CA2234106A1 - Process for controlling cone tilt angle in mixtures of smectic liquid crystal compounds - Google Patents

Abstract

A process for controlling the cone tilt angle of a tilted smectic liquid crystal composition comprises the step of combining (a) at least one liquid crystal composition comprising at least one smectic or latent smectic liquid crystal compound comprising (i) an aliphatic fluorocarbon terminal portion comprising a terminal fluoroalkyl or fluoroether group and an alkylene group having at least two carbon atoms and containing at least one catenary ether oxygen atom, (ii) an aliphatic hydrocarbon terminal portion, and (iii) a central core connecting the terminal portions; and (b) at least one liquid crystal composition comprising at least one smectic or latent smectic liquid crystal compound; with the provisos that at least one of the compositions (a) and (b) comprises at least one chiral liquid crystal compound and that the combining of compositions (a) and (b) provides an optically active, tilted chiral smectic liquid crystal composition. The process enables control of cone tilt angle and thereby control of the brightness characteristics of liquid crystal display devices.

Description

W O 97/13822 PCTrUS96tlS760 PROCESS FOR CONTROLLING CONE TILT ANGLE II~ l~llX 1 UKES OF
SMECTIC LIQUID CRYSTAL COMPOUNDS

Field of the Invention This invention relates to a process for prepal h~g mixtures of smectic or latent smectic liquid crystal compounds having a controlled cone tilt angle. In other aspects, this invention relates to fluorinated, smectic or latent smec,tic liquid crystal compounds useful in the process; to mixtures prepared by the process; and to e1ectrooptical display devices containing the mixtures.
Back~round of the Invention Devices employing liquid crystals have found use in a variety of electrooptical applic~tions, in particular those which require compact, energy-efficient, voltage-controlled light valves, e.g., watch and calculator displays, as well as the flat-panel displays found in portable computers and compact televisions.
Liquid crystal displays have a number of unique characteristics, including low voltage and low power of operation, which make them the most pror,.i~ing of the noa-emissive electrooptical display ç~n~id~tes currently available.
One of the most important characteristics of a liquid crystal display device is its response time, i.e., the time required for the device to switch from the on (light) state to the off (dark) state. In a ferroelectric or anti-ferroelectric device, response time (T = tlSin2(~/P5E) iS proportional to the rotational viscosity (~) of the liquid crystal compound(s) contained within the device, is also proportional to the square of the sine of the cone tilt angle (~) of a tilted smectic mesophase of the compounds, and is inversely proportional to the polarization (P,) of the compounds and to the applied electric field (E). Thus, response time can be reduced by using compound(s) having high polarizations and/or low viscosities and/or low cone tilt angles, and such compounds are greatly desired in the art.
Other important characteristics of a liquid crystal display device are its brightness and contrast ratio. High brightn~ss and contrast ratios provide enhanced optical discl imindlion and viewing ease and are therefore pl efe. l ed.

2 PCTtUS96/15760 Brightness is related to the intensity of light tr~n.cmitted through a device, which for a surface-stabilized ferroelectric device (as described in U.S. Patent No.
4,367,924) with two polarizers can be lepresenled by the equ~tion I = Io (sin2(4~)) (sin2(7~nd/~)), where Io = tr~n~misiion through parallel polarizers, ~3 = liquid crystal cone tilt angle, ~n = liquid crystal birefringence, d =
device sparing and A = wavelength of light used. The ".a~i,nu", l~;~nc,..;e ;on is obtained when both the terms sin2(4~)) and sin2(7~nd/~) are at a m~im..m (each term equals one). Since the first term is at a m~ximl~m when the liquid crystal composition in the device has a cone tilt angle of 22.5 degrees, liquid crystal compounds which have cone tilt angles close to 22.5 degrees (or which can be mixed with other liquid crystal compounds to form compositions having cone tilt angles close to 22.5 degrees) are also highly desired in the art.
In particular, since many fluorine-cont~ining liquid crystal compounds have cone tilt angles which exceed the optimum value of 22.5 degrees, materials and methods for reducing cone tilt angle are needed. Although hydrocarbon liquid crystal compounds have low cone tilt angles (below 22.5 degrees), they generally cannot be used for this purpose due to their inco",palibility with fluorine-cont~;~.;..g Iiquid crystal compounds (which generally leads to loss of the active mesophase).
In addition to fast re~yollse times and optimized tilt angles, liquid crystal compounds should ideally possess broad smectic temperature ranges (to enable operation of a display device over a broad range of temperatures) or should be capable of co",bh,alion with other liquid crystal compounds without adverselyaffecting the smectic phase behavior of the base mixture.
Summarv of the Invention It has been discovered that the cone tilt angle of certain fluorine-Con~ liquid crystal compounds can surprisingly be reduced (and the smectic C
mesophase often surprisingly bro~dened) by inserting an extended hydrocarbon ether group Adjacent to a terminal fluoroalkyl or fluoroether group. It has alsobeen discovered that such compounds (as well as those which do not exhibit a WO 97/13822 rCT~US96/15760 smectic C mesophase) can be used in adl"iAIure with certain other liquid crystalcompounds to control or adjust the cone tilt angle of the resultant mixture without signifiç~nt adverse effect on the smectic C mesophase of the base composition.
Thus, in one aspect, this invention provides a process for controlling S the cone tilt angle of a tilted smectic liquid crystal composition while subslal,lially ~"~ ing or even improving the tc.~lpclalllre range ofthe tilted smectic ",esophase of the cG"~pos;lion. The process comprises the step of co...l,;n;ne (a) at least one liquid crystal composition cGIlllJlisillg at least one smectic or latent smectic liquid crystal compound comprising (i) an aliphatic fluorocarbon terminal 10 portion co-np~ising a terminal fluoroalkyl or fluoroether group and an alkylene group having at least two carbon atoms and co.~l~;ning at least one catenary (i.e., in-chain and bonded only to carbon atoms) ether oxygen atom, (ii) an aliphatic hydrocarbon terminal portion, and (iii) a central core connecting the terminal portions; and (b) at least one liquid crystal composition co",~,isi"g at least one smectic or latent smectic liquid crystal compound; with the provisos that at least one of the compositions (a) and (b) comprises at least one chiral liquid crystalcompound and that the combinillg of compositions (a) and (b) provides an optically active, tilted chiral smectic liquid crystal composition. (Latent smectic liquidcrystal compounds are those which by themselves may not exhibit certain smectic 20 mesophase(s), e.g., tilted smectic mesophase(s), but which, when in admixture with compounds having smectic mesophases or with other compounds having latent smectic l"esophases, develop or exhibit smectic mesophases under appropriate condilions.) Plcfe.ably, the former composition(s) (i.e., composition(s) (a)) are utilized in ~mol)nt(s) such that the resulting combh~alion has a cone tilt angle25 between about 10 and about 35 degrees. Composition(s) (b) preferably co",p,ise at least one fluorine-co..l~;nil-g liquid crystal compound.
The process of the invention enables control of cone tilt angle and thereby control of the brightness characteristics of liquid crystal display devices.
The process is especially useful for reducing cone tilt angle in mixtures of fluorine-30 con~ p smectic or latent smectic liquid crystal compounds (plcrcldblycompounds having fluorinated terminal portions, such as those compounds wo 97/13822 PCT/US96/15760 disclosed, for example, in U.S. Pat. Nos. 4,886,619 (Janulis), 5,082,587 (Janulis), 5,262,082 (Janulis et al.), 5,399,291 (Janulis et al.), and 5,437,812 (Janulis et al.) and in U.S.S.N. 08/338,957 (Janulis et al.) and U.S.S.N. 08/338,961 (Janulis et al.), as well as compounds having at least one chiral, fluorinated terminal portion).
The compounds used in the process of the invention (in composition(s) (a)), unlike hydrocarbon liquid crystal compounds, in many cases show excellçnt co"lpalibility with such fluorine-col~ai~ liquid crystal compounds, show a beneficial effect oronly a minimal negative effect on the smectic C te"")elal~lre range ofthe resulting mixtures (even when present at high conce..L, aLions)~ and provide tilted chiralsmectic mixtures having low viscosity and fast electrical response times over broad ten~p~.aL~Ire ranges. In addition, many of the compounds have broad smectic C
te"~pe~aL~Ire ranges, making them useful alone, as well as in admixture with other liquid crystal compounds (as dopants or as the major con,ponellts), for electrooptical display applications.
In other aspects, this invention also provides fluorine-conl~in;.~g smectic or latent smectic liquid crystal compounds useful in the process of the invention; mixtures comprising the compounds; mixtures prepared by the process of the invention; and electrooptical display devices conl~ g the compounds or the mixtures.
Detailed D~sc ;plion of the Invention Compositions suitable for use (as composition(s) (a)) in the process of the invention are liquid crystal compositions which comprise at least one smectic or latent smectic liquid crystal compound comprising (i) an aliphatic fluorocarbon terminal portion comprising a terminal fluoroalkyl or fluoroether group and an alkylene group having at least two carbon atoms and con~ g at least one catenary ether oxygen atom, (ii) an aliphatic hydrocarbon terminal portion, and (iii) a central core connecting the terminal portions. Such smectic compounds exhibit surprisingly lower cone tilt angles and, in many cases, surprisingly broader smectic C mesophases than corresponding compounds which do not have such an alkylene group (having at least two carbon atoms and cont~ining at least one catenary ether W 0 97/13822 PCT~US96/15760 oxygen) in the aliphatic fluorocarbon terrninal portion. The aliphatic fluorocarbon terminal portion of the compounds can be 1 e~ sel.led by the formula -D-Rh-Rf, where Rh is an alkylene group having at least two carbon atoms and con~ at least one catenary ether oxygen atom; Rf is fluoroalkyl (preferably, perfluoroalkyl) S or fluoroether (preferably, perfluoroether); and D is non-directionally selected from the group cQn~;c~ g of a covalent bond, --C(=0)0--C~H2r~ {~--CrH2r - ~--0~c~ 03,C,lH2f,--CrH2.r--~C~ 03~C,H2.--,--0S02--~--S02~~~S02~CrH2r~~
--C~H2fN--S02--~--C-C~~--CH=CH-~
CpH2p+1 --C(=0)~~ ~0(0=)C--CrH2r - ~--CrH2r~N~C(=0)~~ ~H=N--, CpH2pt, {) ,--S--,--N(CpH2p+1~, and combinations thereof, where r and r' are independently integers of 0 to about 20, s is independenlly an integer of I to about 10 for each (C,H2,O), t is an intege of I to about 6, and p is an integer of 0 to about 4. When the Rf group of the fluorocarbon terminal portion is perfluoroalkyl or perf~uoroether, it can contain small amounts of residual carbon-bonded hydrogen atoms but is prere~ably completely fluorinated. Preferably, Rf is perfluoroalkyl or perfluoroether (more pref~r~bly, perfluoroether) and contains from 1 to about 20 carbon atoms (more preferably, from about 4 to about 12 carbon atoms). Rh ~lefe.ably contains from 2 to about 12 carbon atoms (more preferably, from 2 to about 8). D is preferably selected from the group con~.sli~.g of-O-,--C(=O)-, a covalent bond, and co.. ,bhlalions thereof; more preferably, D is -O-.
The central core of the compounds generally comprises at least one or two rings independently sPIected from the group consisting of aromatic, heteloalomalic, alicyclic, substituted aromatic, substituted heteroalo,nalic, and substituted alicyclic rings, the rings being connected one with another by a covalent bond or by chemical groups selected from the group consisting of-COO-, -COS-, -HC=N-, -CH=CH-, -C_C-, and -COSe-. The rings can be fused or non-fused.
The heteroatoms within the heteroaromatic rings co",p,ise at least one atom selected from the group con.~icting of nitrogen, oxygen, and sulfur. Non-arlj~cent ring carbon atoms in the alicyclic rings can be substituted by nitrogen, oxygen, or sulfur atoms.
A class of liquid crystal compounds which can be utilized (e.g., in composition(s) (a)) in the process of the present invention can be I epresenled by the general formula I:

R-(M),-A~N3bB~P~C-D-Rh-Rf (I) Xl Ym Zn where M, N, and P are each independently selected from the group consisting of $~
.

[~ ~N ~ N~

N~, and N ~N ~,~N~

\~ ~ and WO 97/13822 pcTluss6lls76o ~S~ ~ ~

~ , and y ~0 10 a, b, and c are each independently zero or an integer of from I to 3, with the proviso that the sum of a + b + c be at least 1;

each A and B are non-directionally and indepentlçntly s.olected from the group concicting of a covalent bond, -C(=O)-O-, -C(=O)-S-, -C(=O)-Se-, -C(=O)-Te-, -(CH2CH2),;- where k is 1 to 4, -CH=CH-, -C-C-, -CH=N-, -CH2-O-, -C(=O)-, and-O-;
each X, Y, and Z are independently selected from the group consisting of-H, -Cl,-F, -Br, -I, -OH, -OCH3, -CH3, -CF3, -OCF3, -CN, and-NO2;

each 1, m, and n are independently zero or an integer of 1 to 4;
D is non-directionally selected from the group consisting of a covalent bond, ~C(=O)~O~CrH2r~~~0~CrH2r~7~0~(0=)C~CrH2r~~ -C--C-,-CH=CH-, ~C(=O)~, -O~C~H2~0~C~,H2~-~ ~CrH2r~~C~H2~0~tC~H2~J-~ -0-~ -S-~

S -OSO2~,~SO2~,~SO2~CrH2r~,~CrH2r~N~Sf2~~~N(CpH2p+~
CpH2p+, ~CrH2r~N~C(=O)~~~CH--N~~ and col.lbinalions thereof, where CpH2p+1 r and r' are independently integers of 0 to about 20, s is independently an integer of I to about 10 for each (C,H2,O), t is an integer of I to about 6, and p is an integer of 0 to about 4;
R is selected from the group consisting of ~O~((CqH2q v~(R')v)~O)w~CqH2q+1v~(R')v~
~((CqH2qlv~(R')vl)~O)w~CqH2q+1v~(R')v~

~C(=O)~O~CqH2q+1v~(R')v~ ~O~(O=)C~CqH2q+1v~(R'~v~
D

l\
--W W--CqH2q+l-v~R )v, and \l D

~cR~H-(D)g-cR~H-cqH2q+l-v-(R~)v ~

where each R'is independently selected from the group consisting of-CI, -F, -CF3, -NO2~ -CN, -H~~CqH2q+1~
~O~(O=)C~CqH2q+1~ -C(=O)-O-CqH2q+1, -Br, -OH, and ~OCqH2q+1 (plert;l~bly,-H or -F); q' is independently an integer of I to about 20 for each (CqH2q-O); q is aninteger of I to about 20; w is an integer of 0 to about 10; v is an integer of 0 to g _ about 6; each v' is independently an integer of O to about 6; g is an integer of 1 to about 3; each D is independently and non-directionally selected from the group set forth for D above, with the proviso that the ring cGn~ g D has from about 3 to about 10 ring atoms; each W is independently s~lected from the group consisting of S N, CR', and SiR';

Rh is an alkylene group having at least two carbon atoms (preferably, from 2 to about 12 carbon atoms; more preferably, from 2 to about 8) and co..~ g at least one catenary ether oxygen atom; and Rf is fluoroalkyl or fluoroether (p, er~lably, perfluoroalkyl or perfluoroether; more preferably, perfluoroether) and preferably contains from 1 to about 20 carbon atoms (more preferably, from about 4 to about 12 carbon atoms).
Particularly prerelled Rh moieties can be represented by the general formula ~C,H2,03,CtJH2r--, wherein s is independently an integer of 1 to about l O
for each (C,H2,0) (preferably, about 2 to about 7), t is an integer of 1 to about 6 (preferably, 1 to about 3), and r' is an integer of 1 to about 10 (preferably, 1).
In defining Rf, particularly preferred fluoroalkyl groups are those which can be ~e~,rese~lled by the formula ~CqF2qX'~ where q is as deflned above (and, plefel~bly, is at least about 3) and X' is hydrogen or fluorine. Other useful fluoroalkyl and fluoroether groups are those which can be rel)rese,lled by the formula -Rf'-Rh', where Rf' is a linear or branched, perfluorinated or partially-fluorinated alkylene group having from 1 to about 10 (preferably, from about 2 to about 6) carbon atoms and optionally co..~ nl-g one or more catenary, i.e., in-chain, ether oxygen atoms, and Rh' is a linear or branched alkyl group having from 1 to about 14 (preferably, from about 3 to about 10) carbon atoms and optionallycor.~ ng one or more catenary ether oxygen atoms. Preferably, Rf' is perfluorinated, both Rh' and Rf' are linear, and at least one of the groups Rh' and Rf' cont~ins at least one catenary ether oxygen atom. More preferably, Rh' or 30 both Rh' and Rf' contains at least one catenary ether oxygen atom.

WO 97/13822 PCT/US96tl5760 Particularly pl cçel l ed perfluoroether groups are those which can be ~epl~senled by the formula -(cxF2xo)zcyF2ytl~ where x is independently an integer of I to about 10 for each (CxF2xO)~ y is an integer of 1 to about 10, and z is an integer of 1 to about 10. Pl erel ably, the perfluoroether group is linear, x is~ 5 ;.. ~e~,e,n~ently an integer of 1 to about 8 for each (cxF2~o)~ y is an integer of 1 to about 6, and z is an integer of 1 to about 6.
Many ofthe perfluoroether group-c~ .;..g liquid crystal compounds used in the process of the invention when used alone or when mixed with each other or with other fluorine-cG. ~ g liquid crystal compounds (preferably, the perfluoroether group-cor.l~ g Iiquid crystal compounds described in U.S. Pat. Nos. 5,262,082 (Janulis et al.) and 5,437,812 (Janulis et al.) and in U.S.S.N. 08/338,957 (Janulis et al.) and U.S.S.N. 08/338,961 (Janulis et al.)) exhibit a reduced tel~,l)e~ re dependence of the smectic interlayer spacing This p. op~. ly provides for the spontaneous generation of a bookshelf type layer structure, which is ideal for a tilted chiral smectic liquid crystal device.
A preferred subclass of liquid crystal compounds for use in the process of the invention (e.g., in composition(s) (a)) are those compounds whichcan be rep. t;~en~ed by forrnula I, supra, wherein Rf is fluoroether (pl tÇel ably, perfluoroether) and Rh is represe.-led by the directional general formula ~C,H2,O~,C~H2f, wherein s is independently an integer of 2 to about 10 (preferably, 3 to about 10; more preferably, 3 to about 7) for each (C,H2~O), t is an integer of I to about 6 (preferably, 1 to about 3; more preferably, 1 to 2), and r' is an integer of 1 to about 10 (ple~l~bly, 1 to about 5; more p.e~ldbly, 1); with the proviso that the compounds exhibit at least one tilted smectic mesophase.
25 Preferably, Rh has from about 3 to about 12 carbon atoms (more preferably from about 4 to about 8).
Another preferred subclass of liquid crystal compounds for use in the process of the invention (e.g., in composition(s) (a)) are those compounds which can be represe..led by formula I, supra, wherein Rf is fluoroether (preferably, perfiuoroether) and Rh is ~epresented by the directional general formula ~C~ O~GIH2r--, wherein s is independently an integer of 3 to about 10 WO 97/13822 pcTluss6/ls76o (preferably, 3 to about 7) for each (C~H2,O), t is an integer of 1 to about 6 (preferably, 1 to about 3; more preferably, 1 to 2), and r' is an integer of I to about 10 (preferably, 1 to about 5; more preferably, 1); with the proviso that the compounds do not exhibit at least one tilted smectic mesophase. P, er~, ably, Rh5 has from about 4 to about 12 carbon atoms (more preferably from about 4 to about 8).
Such pr~re.~ed compounds, in general, have enh~nced smectic mesophases and low cone tilt angles (relative to the cG,l~sponding compounds which do not contain an extended hydrocarbon ether group ~tijacçnt to a terminal10fluoroalkyl or fluoroether group) making them useful alone, as well as in ~dmi~re with other liquid crystal compounds (as dopants or as the major components), forelectrooptical display applications. Mixtures of the compounds with other liquidcrystal materials can be formulated to provide desired transition t~llpelaLLlre broad mesophase te~ el~Lllre ranges, and reduced cone tilt angles.
15The fluorine-containing liquid crystal compounds useful in carrying out the process of the invention can be prepared by a process comprising the steps of (a) mixing at least one compound r~rese.lted by the formula R~M~,Aff~b-B' (II) Xl Ym with at least one compound l ~ ,icuLed by the formula B~P3c~D~Rh~Rf (III) Zn WO 97/13822 PCTtuSs6/15760 or rnixing at least one compound represented by the forrnula R~ta~A' (IV) X, with at least one compound represented by the formula A"~N~bB~P3C-D-Rh-Rf (V) l l Ym Zn whereM,N,P,a,b,c,A,B,X,Y,Z,l,m,n,D,R,Rh,andRfareasdefined above for formula I; and each A', A", B', and B" are indep.ond~ntly s~le~led from the group consisting of -H, -Cl, -Br, -I, -OH, -COOH, -CH(CH20H)2, -SH, -SeH, -TeH, -NH2, -COCI, -CHO, -OSO2Rf", -OSO2CH3, ~NH(C=O)OCqH2q+ 1, -NCO, -OSOrcyclo(c6H4)-cH3~ -CH2COOH, and-CH(C(O)O-CqH2q+l)2, where Rf" is a perfluoroalkyl group having from 1 to about 10 carbon atoms and qis an integer of 0 to about 20, and with the proviso that A' can enter into an addition or condenc~tion reaction with A" and that B' can enter into an addition or condenc~tion reaction with B";

and (b) allowing compounds II and III or compounds IV and V to react, optionallyin the p.esel-ce of suitable coupling agent(s), i.e., reagent(s) which effect coupling.
Liquid crystal compositions suitable for use (as composition(s) (b)) in ~miyture with the above-described liquid crystal compositions (i.e., composition(s) (a)) are those liquid crystal compositions which CG"~ ise at least one smectic or latent smectic liquid crystal compound. At least one of compositions (a) and (b) must possess optical activity in order for the resulting co",bina~ion to exhibit a cone tilt angle. Especially suitable compounds for use in - composition(s) (b) are fluorine-cont~ining, smectic or latent smectic liquid crystal compounds (preferably compounds having fluorinated terminal portions such as -- l3 those compounds described, for example, in U.S. Pat. Nos. 4,886,619 (Janulis), 5,082,587 (Janulis), 5,262,082 (Janulis et al.), 5,399,291 (Janulis et al.), and5,437,812 (Janulis et al.) and in U.S.S.N. 08/338,957 (Janulis et al.) and U.S.S.N.
08t338,961 (Janulis et al.), as well as compounds having at least one chiral, fluorinated terminal portion).
The process ofthe invention can be carried out by co.,.hi~ p.
composition(s) (a) and composition(s) (b). The col.lb;ning or mix-ing of the compositions can be effected by introducing the compositions to a vessel, generally with simlllt~neous and/or subsequent agitation or stirring, e.g., roller mixing. The vessel can be either an open or a closed vessel of a size which is sufficient to hold both compositions while allowing room for mixing. The compositions can be formed prior to co.l.bil-alion with each other, or, alternatively, one or more of the components of either can be co.nbined with one or more of the components of the other prior to addition of the rem~ining components. Any order and manner of lS combination of the components of the compositions is acceptable. The resulting colllbinalion is preÇel ~bly ~git~ted or stirred sufficiently that a homogeneousmixture is achieved. This is preferably f~ciiit~ted by applying sufficient heat to melt the conlbil-alion or by dissolving the combination in a solvent, e.g., a polar aprotic solvent, with subsequent solvent removal, e.g., by evaporation.
The liquid crystal compounds to be utilized in the process can be selected based upon the magnitudes of their cone tilt angles (or, in the case oflatent smectic liquid crystal compounds, the m~pnitudes of the cone tilt angle of mixtures cont~ining the latent compound(s)), which can be determined by using a polarizing microscope equipped with a hot stage, as described below in the Exam~lcs. In general, composition (b) (generally having a greater cone tilt angle) can be comhined with composition (a) (generally having a smaller cone tilt angle) to obtain a combination having a desired interme~i~te cone tilt angle. Preferably, composition(s) (a) are utilized in amount(s) such that the resulting cor..hin~l;on has a cone tilt angle between about 10 and about 35 degrees (more preferably, between about 18 and about 26 degrees; most preferably, between about 18 and about 23 degrees). However, in some cases a cone tilt angle outside of these ranges may be -- 14 _ desirable for a particular purpose and can be achieved by the mixing of compositions (a) and (b). Net cone tilt angles within these ranges can generally be achieved through an iterative process of col..bi"i"g co~posilions (a) and (b) invarying ratios- and measuring the net cone tilt angles of the resulting co,.lbhlalions.
Objects and advantages of this invention are further illustrated by the following t,.a"l,~les, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention.
In the following e,~"l~)les, all telnl)e,aL~res are in degrees Celsius 10 and all parts and p~celages are by weight unless in~ ted otherwise.
Commercially available materials were chemically tran~ro.ll.ed by reaction pathways well-known to those skilled in the art and detailed in the examples.
Chemical transformations were comprised of acylation, esterification, etherification, alkylation, and combinations thereof using fluorine-cont~inin~ and non-fluorine-cont~ining react~ntc to provide the precursor compounds, which, in turn, were allowed to react together to yield the fluorine-cont~ining liquid crystal compounds used in the process of the invention.
Liquid crystal compounds pr~pared as desc-i~ed below were characterized by their melting or boiling points, and their structures were confirrned using at least one of the following methods of analysis: high pressure liquid chlol..a~ography (HPLC); 13C, IH, and ~9F nuclear magnetic resonance (NMR); and infrared and mass spectroscopies.

EXAMPLES
The 5-alkyl-2-(4-hydroxyphenyl) pyrimidinPs used in the examples were prepared eSsenti~lly as described by Zaschke and Stolle in "Synthese niedri~cchmPl~ender Kristallin-Flussiger Heterocyclen; 5-n-Alkyl-2-[4-n-alkanoyloxy-phenyl]pyrimidine," Z.Chem. 15, 441-3 (1975). (S)- and (R)-2-fluoro-decyl-p-tol-lenPsulfonate were prepared essenti~lly as described by Nohira et - 30 al. in Mol. Cryst. Liq. Cryst. 180B, 379 (1990). Fluorinated alcohols were ~re~,ared escp~nti~lly as described in U.S. Patent No. 5,262,082 (Janulis et al.) by sodium borohydride reduction ofthe collea~)onding perfluorinated acids (or derivatives), which had been p~cpa~d by electroçhe...ic~l fluorination (ECF) or by direct fluorination (using elemPnt~l fluorine) ofthe co~s~onding hydrocarbon acids (or derivatives). See, e.g., the description of ECF given in U.S. Patent No.
S 2,519,983 (Simons). Direct fluorination is described, e.g., in U.S. Patent No.
5,362,919 (Costello et al.).

E~amples 1-39 describe procedures for preparing liquid clystal compounds which can be used in the process of this invention. (The compounds of Examples 1-37 are liquid crystal compounds of the invention.) The r' ~ ;c structure of each compound is given in Table 1.

E~ample 1 Preparation of 5-OCtYI2 (4 (2 (2 (I~Q ~1Y~IOI)UtOXY)tetranUOrOethOXY)-2~2-ditluoroetho~y)buto~y)phenyl)pyrimidine A 500 mL flask was charged with 4-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)- 1 -bromobutane (21.9 g, 38.5 mmol; p,epared from 1,4-diblulnob~ltane and 2-(2-(non~fluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethanol), 5-octyl-2-(4-hydroxyphenyl)pyrimidine (10 g, 35 mmol), potassium carbonate (5.4 g, 39 mmol), and acetonitrile (200 mL), and the resulting mixture was stirred and refluxed overnight under nitrogen. Toluene (150 mL) and water (150 mL) were added to the refluxed mixture. The resulting toluene layer was collected and residual water removed by distillation using a Dean-Stark apparatus. The toluene layer was thenfiltered through a pad of silica gel and the toluene removed under reduced pressure. The crude product was further purified by distillation using a Kugelrohr appalat~ls (b.p. 210-15~C at 0.1 torr). The resulting yield was 14.4 g.

Example 2 Preparation of ~Octyl-2-(~(2-(2-(nonatluorobutoxy)tetraf1uoroethoxy~2,2-d-" ~ c~tho~y)pentylo~y)phenyl)pyrimidine The title compound was p,~;paled ~ssenti~lly as in Example 1 by co.. h;~;nP. 5-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy) 2,2 difluoroethoxy)pentyl bromide (23.5 g, 38.5 mmol; prepared from 1 5-d;btc ",up- Iltane and 2-(2-(non~fluorobutoxy)tetrafluoroethoxy)-2,2-difluorocil~ ~-ol) with 5-octyl-2-(4-hydroxyphenyl)p~,i""di"e (10 g, 35 mmol). Ayield of 19.8 g was obtained (b.p. 200-10~C at 0.4 torr).

E~amPle 3 Preparation of S-Octyl-2-(3-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-dinuoroetho~y)propoxy)phenyl)pyrimidine The title compound was p,~paled escenti~lly as in Exarnple 1 by co...~ .; .g 3-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propyl bromide (14.8 g, 26.8 mmol; p,epared by co~.~bin;ng 1,3-dil,~u~op-opane and 2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2 2-difluoroethanol) with 5-octyl-2-(4-hydroxyphenyl)pyrimidine (7.3 g, 26.8 mmol).
Af~er r-ofl~xing for 7 hours toluene and water were added to the resulting mixture, and the resulting organic phase was extracted with three 30 mL aliquots of brineand then dried over anhydrous MgSO4. The organic phase was then filtered, the solvent was removed under reduced pressure and the resulting material was dissolved in 5 volume percent ethyl acetate/hexane. The resulting hexane/ethyl acetate solution was purified by flash chl ol"a~ography on silica gel and the solvent mixture was removed under reduced pressure. The resulting product was further purified by distillation using a Kugelrohr apparatus to provide a yield of 14.5 g.

WO 97/13822 PcT/uss6/15760 Example 4 Preparation of 5-Octyl-2-[4-(6-(2-(2-(ro ~fluorobutoxy)tetranuoroethoy) 2,2- difluoroethoxy)hexyloxy)phenyl]pyrimidine The title compound was prepared eSsenti~lly as in Example 1 by cor"bining 5-octyl-2-(4-hydroxyphenyl)pyrimidine (1.01 g, 3.55 mmol) and 6-(2-(2-(non~fluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)-l-bromohexane (2.4 g, 4.03 mmol; p,~paled by colllbinillg 1,6-dibromohexane and 2-(2-(non~fluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethanol). The resulting crude product was isolated and further purified e~sçnti~lly as descl;l,ed in Example 3, eluting with I vol.% ethyl acetate/toluene Example 5 Preparation of 5-Hexyloxy-2-14-(5-(2-(2-(nol ~fluo.obutoxy)tetranuoroethoxy)-2,2-dillL.oroelhoxy)pentyloxy)phenyl]pyrimidine The title compound was plepaled essenti~lly as in Example 1 by colllbilling 5-hexyloxy-2-(4-hydroxyphenyl)pyrimidine (8.0 g, 29.4 mmol) and 5-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)-l-bronlopenla~le(18.6 g, 32 mmol, Example 2). The resulting crude product was isolated and further purified ess~nti~lly as descl;l~ed in Example 1 (b.p. 210-25~C at 0.3 torr).

Example 6 Preparation of 5-Heptyloxy-2-14-(3-(2-(2-(non~ o. ~,butoxy)tetranuoroethoxy)-2,2-ditluoroethoxy)propoxy)phenyl]pyri~i~ine The title compound was p~,"al ed e~enti~lly as described in Example 1 by colllbil-illg 5-heptyloxy-2-(4-hydroxyphenyl)pyrimidine (3.0 g, 10.0 mmol) and 3-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)-l-bromopropane (6.6 g, 12.0 mmol, Example 10). The product was isolated by addition of water (60 mL) to the resulting mixture, followed by filtration and recryst~ tion from ethanol. The recryst~lli7ed p~eciyilale was dried at about 130~C, and the resulting product was further purified by Kugelrohr distillation (b.p.
180-190~C at 2 torr; yield 5.6 g).

Example 7 Preparation of ~-He~yloxy-2-[4-(7-(2-(2-(nonanuorobutoxy)tetranuoroethoxy)-2,2-din. ~ o~y)heptyloxy)phenyl]pyrimidine The title compound was prepa,ed essçnti~lly as des.";bed in Example I by co...b;.~;..g 5-hexyloxy-2-(4-hydroxyphenyl)pyrimidine (3.0 g, 11.0mmol) and 7-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)-l-bromoheptane (7.7 g, 12.0 mmol; prepared by combining 1,7-dibromoheptane with 2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethanol). Product was isolated by addition of water (50 mL) to the resulting mixture, followed by filtration and recryst~ tion from ethanol. The recryst~ d precip;lale was dried at about 130~C, and the resulting product was further purified by Kugelrohr distillation (b.p. 210-222~C at 0.03 torr; yield 7.3 g).

Example 8 Preparation of 5-Octyl-2-[4-(4-(5-(2-(ncr~tl-~orobutoxy)tetralluoroethoxy)-2,2,3,3,4,4,5,5-octafluoropentoxy)butoxy)phenyllpyrimidine The title compound was prepa~ ed essçnti~lly as in Example 1 by co~"bi"illg 5-octyl-2-(4-hydroxyphenyl)pyrimidine (1.0 g, 3.52 mmol) and 6-(5-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,-octafluo, ope"~yloxy)- 1-bromobutane (3.07 g, 4.0 mmol; prepared by colllb;ning 1,4-dibromobutane and 2-(2-(non~fluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5-octafluoropentanol). Theresulting crude product was isolated and further purified essçnti~lly as described in Example 3, eluting with 20 volume percent ethyl acetate/cyclohexane, to yield 2.53 g of purified product.

Example 9 Preparation of 5-Octyl-2-[4-(2-(6-(2-(non~ robutoxy)tetrafluoroethoxy~
2,~,t,~4,~ 6,6-decanuorohexyloxy)etho~y)phenyllpyrimidine S The title compound was prcpa~d ess~nti~lly as in Example 1 by col"bh-ing 5-octyl-2-(4-hydroxyphenyl)pyrimidine (1.04 g, 3.64 mmol) and 2-(6-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3 ,3 ,4,4,5,5,6,6-dec~fluorohexyloxy)-1-p-tolu~n~s~lfonyl ethane (3.36 g, 4.05 mmol; prepared by colllbil-ing ethyleneca,l,onate and 6-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6 dec~fluQrohexanol and then prepa~ing the p-toluçnçsl~lfonate from p-toluenesulfonyl chloride. The resulting crude product was isolated and further purified e~senti~lly as described in Example 3, eluting with ethyl acetate/hexane, to yield 2.88 g of purified product.

E~ample 10 Preparation of S-Octyl-2-14-(3-(6-(2-(nonanuorobutoxy)tetranuoroethoxy)-2,2,3,3,4,4,~ 6,6-doder~luorohexyloxy)propo~cy)phenyl]pyrimidine The title compound was prepared ess~nti~lly as in Example 1 by co~b;~lJng 5-octyl-2-(4-hydroxyphenyl)pyrimidine (1 g, 3.51 mmol) and 3-(6-(2-(non~fluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6-dec~flllQrohexyloxy)-l-blollloplopane (3.04 g, 4.04 mmol; prepaled by co~llbi~.;ng 1,3-dibromopropane and 2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6-decafluorohexanol). The resulting crude product was isolated and further purified essenti~lly as descl;bed in Example 3, eluting with 2 volume percent ethyl acetateltoluene, to yield 2.68 g of purified product.

E~cample 11 Preparation of S-Octyl-2-[4-(4-(6-(2-(nonatluorobutoxy)tetr~flu0.o~lhoxy)-2,2,3,3,4,1,5,S,6,6 de~ ~fluorohexyloxy)buto~y)phenyl]pyrimidine The title compound was pl epa~ ed ecsçnti~lly as in Example 1 by S cG.. ,binil~g 5-octyl-2-(4-hydroxyphenyl)pyrimidine (1.01 g, 3.56 mmol) and 4-(6-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6-deç~fluQrohexyloxy)-l-bromobutane (3.07 g, 4.0 mmol; prepaled by co,..~ e 1,4-dibromobutane and 2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6-deç~fluorohexanol).
The resulting crude product was isolated and further purified ~cc~nti~lly as described in Example 3, eluting with 15 volume percent ethyl acetate/hexane, to yield 2.3 g of purified product.

E~cample 12 Preparation of 5-(2-(Ethoxy)ethoxy)-2-[4-(3-(2-(2-1 5 (non~tluorobutoxy)tetr:ltluoroethoxy)-2,2-dinuoroethoxy)propoxy)phenyl]pyrimidine A S00 mL flask was charged with 5-ben_yl-2-[4-hydroxyphenyl]pyrimidine (10.0 g, 40 mmol), 3-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)-1-bromopropane (24.2 g, 44 mmol, Example 3), potassium carbonate (6.1 g, 44 mmol), and anhydrous acetonitrile (100 mL), and the resulting mixture was stirred ovemight at 85~C
under nitrogen. Water (150 mL) was added and the mixture was cooled to 5~C
and then filtered and dried to produce 5-benzyloxy-2-[4-(3-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrirnidine. This inte~ ediale was filrther purified by recryst~lti7~tion from acetone, and the benzyl protecting group was removed by hydrogenation using Pd/C catalyst.
The title compound was prepared essenti~ily as in Example 1 by con.l)in.ng 5-hydroxy-2-[4-(3-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (1.0 g, 1.51 mmol,) and 2-bromoethyl ethyl ether (0.58 g, 3.79 mmol). The resulting crude product was isolated and fiJrther purified eSsenti~ly as described in Example 3, eluting with 30 volume percent ethyl acetate/hexane, to yield 0.76 g of purified product.

Example 13 Preparation of ~(2-(2-(Butoxy)ethoxy)ethoxy~2-14-(3-(2-(2-(nonanuorobutoxy)tetr~'' Q~ ~tho~y)-2,2-dinuoroethoxy)propoxy)phenyl~pyrimidine The title compound was prepared essPnti~lly as in Example 1 by colllbinillg 5-hydroxy-2-[4-(3-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (1.22 g, 1.85 mmol, Example 10) and l-bromo-2-(2-butoxyethoxy)ethane (0.81 g, 3.62 mmol). The resulting crude product was isolated and further purified essçnti~lly as described in Example 3,eluting ~vith 30 volume percent ethyl acetate/hexane, to yield 1.13 g of purified product.

Example 14 Preparation of 5-(2-(S)tluorooctyloxy)-2-14-(3-(2-(2-D~ orobutoxy)tetranuoroelhoxy)-2,2-ditluoroethoxy)propoxy)phenyl]pyrimidine The title compound was prepared essçnti~lly as in Example 1 by co~..b;..ing 5-hydroxy-2-[4-(3-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (5.9 g, 8.9 mmol, Example 12) and 2-(R~fluorooctyl-l-p-toluenes~lfonate (2.75 g, 9.5 mmol; which can be prepared as described by Nohira et al. in Mol. Cryst. Liq. Cryst. 1 80B, 379 (1990)). The resulting crude product was isolated and further purified by recryst~lli7~tion from ethanol to provide a yield of 5.3 g.

WO 97/1~822 PCTtUS96/15760 Example 15 Preparation of 5-Hexyloxy-2-[4-(2-(2-(2-(2-(nonanuorobutoxy)tetran-.oroethoxy)-2,2-~-~ o oethoxy)ethoxy)ethoxy)phenyl]pyrimidine The title compound was prepared ess~nti-lly as in Example 1 by col.lbining 2-(2-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)ethoxy)ethyl bromide (7.7 g of 90% purity by gas ~_I,J orl,atography 11.8 mmol) with 5-hexyloxy-2-(4-hydroxyphenyl)pyrimidine (3.0 g, 11.0 mmol).
The resulting product was isolated by addition of water (50 mL) to the reaction mixture, followed by filtration and recryst,A,lli7~tion from ethanol. The recrystA~ Pd preci~ te was dried at about 130~C, and the resulting product was further purified by distillation using a Kugelrohr apparatus (b.p. 185-210~C at 0.01 torr; yield 5.6 g).

ExamPle 16 Preparation of S-Octyl-2-[4-(4-(4-(2-(non~1uDrobutoxy)tetra~luoroethoxy)-"1,q ~AY~nno obutoxy)butoxy)phenyllpyrimidine The title compound was prepared essenti-lly as in Example 1 by col"bill;l,g 4-(4-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4-hey~fluorobutoxy)butyl bromide (25.6 g, 38.5 mmol; plepart;d by combining 1,4-dibromobutane and 2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethanol) with 5-octyl-2-(4-hydroxyphenyl)pyrimidine (10 g, 35 mmol).
The resulting product was further purified by recryst~ tion from heptane, followed by Kugelrohr distillation (b.p. 200-210~C at 0.4 torr; yield of 20.4 g).

CA 02234l06 l998-04-06 W 0 97/13822 PCT~US96/15760 E~ample 17 Preparation of 5-Hexyloxy-2-[4-(3-(2-(2-(tritluoromethoxy)tetran- Dl~oethoxy)-2,2-difluoroethoxy)propo~y)phenyllpyrimidine The title compound was prepared es~enti~lly as in Example 1 by co.,.bil~ing 3-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)-1 chlolop.upane (4.5 g, 11.7 mmol; })re?arc~ by colllb;ning 1-bromo-3-chloroplopane with 3-(2-(2-(trifluoron ethoxy)tetrafluoroethoxy) 2,2 difluoroethanol) with 5-hexyloxy-2-(4-hydlo~phe,lyl)pyl;lllidille (3.0 g, 11.0 mmol). The resulting product was isolated by addition of water (50 mL) to the reaction mixture, followed by filtration and recryst~lli7~tion from ethanol. Therecryst~lli7ed precip;late was dried at about 130~C, and the resulting product was further purified by distillation using a Kugelrohr appala~us (b.p. 180-183~C at 0.1 torr; yield of 3 .9 g).

Example 18 Preparation of S-Octy1-2-[4-(3-(2-(2-(pent~f ~1 oell.oxy)tetratluoroethoxy)-2,2-ditluoroethoxy)propoxy)phenyllpyrimidine The title compound was prepared essenti~lly as in Example 1 by coll~ g 5-octyl-2-(4-hydroxyphenyl)pyrimidine (2.0 g, 7.3 mmol), 3-(2-(2-(pentafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)-1-bromop.opane (3.38 g, 7.47 mmol; prepared by co--.bh~ g 1,3-dibromopropane with 3-(2-(2-(pentafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethanol), and potassium carbonate (1.16 g, 8 43 mmol) in acetonitrile (20 mL) and refluxing the resulting mixture under nitrogen overnight. The mixture was cooled and filtered, and the resulting solids were washed with toluene (50 mL). The toluene was then removed under reduced pressure, and the resulting waxy solid was dissolved in toluene (50 mL) and washed with three 30 mL aliquots of perfluorohexane. A~er removing the toluene under reduced pressure, the resulting crude product was further purified by silica gel chromatography, eluting with 20 volume percent ethyl acetate/hexane, to yield 3.60 g of purified product.

E~ample 19 Preparation of 5-Octyl-2-[4-(4-(2-(2-(pent~" ~rvelho~ty)tetrafluoroetho~cy) 2,2-ditluoroethoxy)butoxy)phenyl]pyrimidine The title compound was prepared ecsçnti~lly as in Example I by C~ g S-octyl-2-(4-hydroxyphenyl)pyrimidine (1.99S g, 7.01 mmol) and 4-(2-(2-(pent~fluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)-1 -bron.ob.ltane (3.44 g, 7.36 mmol; prepa~ed by cG~ ;ng 1,4-dibromob~lt~ne with 3-(2-(2-(pentafl~loroethoxy)tetrafluoroethoxy)-2,2-difluoroethanol). The resulting crudeproduct was isolated and further purified essenti~lly as described in Example 3,eluting with lS volume percent ethyl acetate/hexane, to yield 4.12 g of purifiedproduct.

Example 20 Preparation of S-~Iexyloxy-2-(3-~2-(2-(pentafluoroetho~cy)tetrafluoroethox9)-2,2-di11uoroethoxy)propoxy)phenyl)p~ id- ~
The title compound was prepared essentially as in Example 1 by combining 3-(2-(2-(pent~fl~loroethoxy)tetrafluoroethoxy)-2~2-difluoroethoxy)propyl bromide (5.3 g, 11.7 mmol, Example 18) with 5-hexyloxy-2-(4-hydroxyphenyl)pyrimidine (3.0 g, 11 mmol~ The resulting cmde product was fi~rther purified byKugelrohr distillation (b.p. 185-195~C at 0.4 torr; yield of 4.1 g) WO 97/13822 pcTluss6ll576o E~ample 21 Preparation of 5-Hexyloxy-2-14-(4-(2-(2-(pentaJluoroethoxy)tetranuoloe~' ~xy~2,2-dinuoroethoxy)butoxy)phenyl]pyrimidine The title compound was pl epa- ~d ecs~nti~lly as in Example 1 by co,l,binll-g 4-(2-(2-(pe~t~fl-lQroethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)-1-b~or..obutane (14.9 g, 32.0 mmol, Example 19) with 5-hexyloxy-2-(4-hydroxyphenyl)pyrimidine (8.0 g, 29.4 mmol). The resulting product was isolated by addition of water (160 mL), followed by filtration and recryst~lli7~tion fromethanol. The recrystA~ ed p~ecipitale was dried at about 130~C, and the resulting product was further purified by distillation using a Kugelrohr apparatus (b.p 190-205~C at 0.3 torr; yield of 1~.2 g).

Example 22 Preparation of 5-Hexyloxy-2-14-(5-(2-(2-(pentafluoroetho~y)tetrafluoroethoxy)-2,2-dinuoroethoxy)pentyloxy)phenyl]pyrimidine The title compound was p~ )a, ed escenti~lly as in Example 1 by co.nbin;"g 5-hexyloxy-2-(4-hydroxyphenyl)pyrimidine (2.26 g, 8.3 mmol) with 5-(2-(2-(pent~fl~ .oroethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)- 1 -bromopel-lalle (4.08 g, 8.3 mmol; p.epared by co...bi.-i.-g 1,5-diblolnopentane with 2-(2-(pentafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethanol). Productwasisolated by addition of water (160 mL) to the resulting rnixture, followed by filtration and recryst~ tion from ethanol. The recryst~lli7~d p.ec;~,;tale was dried at about 130~C, and the resulting product was further purified by Kugelrohr distillation (b.p.
190-205~C at 0.3 torr; yield of 15.2 g).

WO 97/13822 PCTtUS96/lS760 E~ample 23 Preparation of 5-(2-(2-(2-Methoxy(ethoxy)etho~cy)ethoxy))-2-14-(4-(2-(2-(pentall~,~ro~lhoxy)tetratluoroethoxy) 2,2-d j A Dr~)~thoxy)butoxy)phenyll pyrimidine - 5 The title compound was prepalt;d ~ss~nti~lly as in Example 12 by first co~l.bining 5-benzyl-2-[4-hydroxyphenyl]pyrimidine (5.0 g, 18 mmol) and 3-(2-(2-(pent~fluoroethoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)- 1 -bl ol,lobul~le (10.3 g, 22 mmol, FY~mple 19) to produce 5-benzyloxy-2-[4-(4-(2-(2-(pent~fluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)butoxy)phenyl~pyrimidine. This intermediate was further purified by recryst~lli7~tion from acetone, and the benzyl protecting group was removed by hydrogenation using Pd/C catalyst.
The resulting 5-hydroxy-2-[4-(4-(2-(2-(pent~fluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)butoxy)phenyl]pyrimidine (1.0 g, 1.74 mmol) was combined with 2-(2-(2-methoxy(ethoxy)ethoxy)-1-chloroethane (0.38 g, 2.1 mmol) using essenti~llythe procedure of Example 1, to provide a product yield of 0.99 g.

E~ample 24 Preparation of 5-Octyl-2-14-(3-(2-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)tetr~ . c ~ thoxy)-2,2-diûuoroethoxy)propoxy)phenyl]pyrimidine The title compound was prepa, ed essenti~lly as in Example 1 by cGmh;~ e 3-(2-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)l-chlolopropane (18.3 g, 38.5 mmol; prepared from 1-bromo-3-chloropropane (107 g, 0.7 mol) and 2-(2-(2-(trifluoromellloxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethanol (125 g, 0.31 mol) ~ossçnti~ily as in Example 2) with S-octyl-2-(4-hydroxyphenyl)pyrimidine (10 g, 35 mmol). The crude product was further purified by Kugelrohr distill~sion (b.p. 200-210~C at 0.4 torr; yield of 10.0 g).

Example 25 Preparation of 5-Octyl-2-[4-(4-(2-(2-(2-(trinuoromethoxy)tetrafluoroetho~y)tetranuoroetho~y)-2,2-dinuoroethoxy)butoxy)phenyl]pyrimidine The title compound was p,epdred essçnti~lly as in Example 1 by CQ~ g 4-(2-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)l-bromobutane (20.9 g, 38.5 mol; pleyaled from 1,4-dibromobutane and 2-(2-(2-(trifluolo.l.ellloxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethanol) with 10 5-octyl-2-(4-hydroxyphenyl)pyrimidine (10.0 g, 0.35 mol). The resulting product was further purified by recryst~lli7~tion from ethanol and subsequent Kugelrohr distillation to provide a yield of 17.5 g (b.p. 195-220~C at 0.1 torr).

Example 26 15 Preparation of 5-Octyl-2-[4-(5-(2-(2-(2-(trinuoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-ditluoroethoxy)pentyloxy)phenyl] pyrimidine The title compound was p.c;pared çcc~nti~lly as in Example 1 by col"bil-ing 5-(2-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-20 difluoroethoxy)l-bromopentane (18.3 g, 38.5 mmol; p,epared from 1,5-dibromope..lane (107 g, 0.7 mol) and 2-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethanol (125 g, 0.31 mol) Çscenti~1ly as in Example 2) with 5-octyl-2-(4-hydroxyphenyl)pyrimidine (10 g, 35 mmol) to provide product boiling at 200-210~C at 0.4 torr (yield of 20.8 25 g) Example 27 Preparation of 5-Octyl-2-[4-(6-(2-(2-(2-(trifluoromethoxy)tetranuoroethoxy)tetrafluoroethoxy)-2,2-dinuoroethoxy)hexyloxy)phenyllpyrimidine The title compound was prepaled essenti~lly as in Fy~mple 1 by cor"binil-g 6-(2-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy) 2,2 difluoroethoxy)-l-bromoheY~ne (85 g, 0.155 mol; pret)ated from 1,6-dibromohexane (500 g, 0.7 mol), 2-(2-(2-(trifluoronlclhoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethanol (150 g, 0.37 mol), and potassium t-butoxide (412 mL of lM solution in t-butanol)) with 5-octyl-2-(4-hydroxyphenyl)pyrimidine (45 g, 0.162 mol). The crude product was further purified by recryst~lli7~tion from heptane and subsequently dried in a vacuum oven (yield of 93.0 g).

Example 28 Preparation of 5-~Iexyloxy-2-14-(3-(2-(2-(2-(trinuoromethoxy)tetranuoroethoxy)tetrafluoroethoxy)-2,2-dinuorcelhoxy)propoxy)phenyl]pyrimidine The title compound was pre~,ared ess~nti~lly as in Example 1 by co",bil-~ng 3-(2-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy) 2,2-difluoroethoxy)-l-chloloplopane (5.42 g, 11.4 mmol, Example 24) with 5-hexyloxy-2-(4-hydroxyphenyl)pyrimidine (3 g, 10.0 mmol). Product was isolated by addition of water (100 mL) to the resulting mixture, followed by filtration and recryst~lli7~tion from ethanol. The recryst~lli7ed pl ec;~;lale was dried at about 130~C, and the resulting product was further purified by Kugelrohr distillation (b.p.
170-180~C at 2.0 torr; yield of 5.4 g).

Example 29 Preparation of 5-Pentyloxy-2-14-(3-(2-(2-(2-(lr;nLoromethoxy)tetranuoroethoxy)tetra~luoroetho~y)-2~2 difluoroethoxy)propoxy)phenyl]pyrimidine The title compound was prepared essPnti~lly as in Example 1 by cQ...bi~ 3-(2-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)-l-chloropropane (6.1 g, 28.0 mrnol, Example 24) with 5-pentyloxy-2-[4-hydrox~phenyl]pyrimidine (3 g, 11.6 mmol) in dimethylro,l.,dlllide and stirring at 120~C overnight to provide product boiling at 185-190~C at 0.3 torr (yield of 5.5 g).

Example 30 Preparation of 5-Heptyloxy-2-14-(3-(2-(2-(2-(trinuoromethoxy)tetranuoroethoxy)tetranuoroethoxy)-2,2-ditluoroethoxy)propoxy)phenyllpyrimidine The title compound was prepared esspnti~lly as in Example 1 by colll~iniilg 3-(2-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)1-chloloplopane (5.5 g, 15.0 mmol, Example 24) with 5-heptyloxy-2-(4-hydroxyphenyl)pyrimidine (3 g, 10.5 mmol) in dimethylforrnamide and stirring at 120~C overnight to provide product boiling at 195-210~C at 0.3 torr (yield of 5.6 g) E~cample 31 Preparation of 5-Octyloxy-2-14-(3-(2-(2-(2-2S (trifluoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-dinuoroethoxy)propoxy)phenyl]pyrilnid ne The title compound was prepared es~Pn~i~lly as in Example 1 by conlbi~ g 3-(2-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)-l-chlolol)ropane (5.2 g, lO.9 mmol7 Example 24) with 5-octyloxy-WO 97/13822 PCT/US96/lS760 2-(4-hydroxyphenyl)pyrimidine (3 g, 10.0 mmol) in dhll~lhylfolll~allude and stirring at 120~C overnight The resulting product was further purified by Kugelrohr distillation (b.p. 195-210~C at 0.3 torr), followed by recryst~lli7~tion from ethanol and ad~lhion~l distillation (yield of 3.5 g).

Example 32 Preparation Or S-~Ieptyloxy-2-14-(4-(2-(2-(2 (trinuoromethoxy)tetranuoroethoxy)tetranuoroethoxy)-2,2-dinuoroethoxy)butoxy)phenyl] pyrimidine The title compound was prepared çcsçnti~lly as in Example 1 by Col..~;~.;ng 4-(2-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)l-bromobutane (6.1 g, 15.0 mmol, Example 25) with 5-heptyloxy-2-(4-hydroxyphenyl)pyrimidine (3 g, 10 5 mmol). The resulting crude product was further purified by recrysallization from ethanol and subsequent Kugelrohr dictill~tion (b.p. 200-210~C at 0.3 torr; yield of 5.2 g).

Example 33 Preparation of S-Octyl-2-14-(5-(2-(nor~ norobutoxy)-2,2-ditluoroethoxy)pentyloxy)phenyll pyrimidine The title compound was plepared ecc~onti~lly as in Example 1 by cG--.b;-.h-g 5-octyl-2-(4-hydroxyphenyl)pyrimidine (6.0g, 21 mmol) and 5-(2-(non~fluorobutoxy)-2,2-difluoroethoxy)-1-bromopentane (12 g, 23 mmol prepared by co",b;n;ng 1,5-dibromope"~ane with 2-(nonafluorobutoxy)-2,2-difluoroethanol). A~er refluxing overnight, the resulting crude product was isolated by filtration and further purified by recryst~lli7~tion from ethanol, followed by Kugelrohr distillation (b.p. 190-200~C at 0.1 torr; yield of 6.4 g).

Wo 97/13822 PCT/US96/15760 Example 34 Preparation of 5-Octyl-2-14-(6-(2-(nonatluorobutoxy)-2,2-dilluoroethoxy)hexyloxy)phenyl]pyrimidine The title compound was prepa~ cd essent~ y as in Example 1 by co-~-bi.. ing 5-octyl-2-(4-hydroxyphenyl)pyrimidine (8.0 g, 28.13 mmol) and 6-(2-(non~flllQrobuloAy)-2~2-difluoroethoxy)-1-bromohexane (14.15 g, 29.54 mmol;
~.~pa.~d by co-,.bh-i.,g 1,6-dibromohexane with 2-(nonafluorobutoxy)-2,2-difluoroethanol). After refluxing overnight, the resulting crude product was isolated by filtration and further purified by recrystalli7~tion from ethanol, followed by Kugelrohr distillation (b.p. 200~C at 0.25 torr).

E~cample 35 Preparation of 5-Octyl-2-14-(4-(2-(2-(tridecafluorohexyloxy)tetrafluoroethoxy)-2,2-difluoroethoxy)butoxy)phenyllpyr~
The title compound was p~ epared es~enti~lly as in Example 1 by co..,bh~ing 5-octyl-2-(4-hydroxyphenyl)pyrimidine (1.03 g, 3.61 mmol) and 4-(2-(2-(tridec~fluorohexyloxy)tetrafluoroethoxy)-2,2-difluoroethoxy)- 1 -bromobutane(2.68 g, 4.02 mmol; prepared from 1,4-dibromobutane and 2-(2-20 (tridec~fluorohexyloxy)tetrafluoroethoxy)-2,2-difluoroethanol). The resultingcrude product was isolated essenti~lly as described in Example 3 and further purified by recryst~lli7~tion from cyclohexane/ethyl acetate to yield 1.85 g of purified product.

25 Example 36 Preparation of 5-Octyl-2-14-(4-(4-(2-(tridecanuorohexyloxy)tetrafluoroethoxy)-2,2,3,3,4,4-hexafluorobutoxy)butoxy)phenyl]pyrimidine The title compound was prepal ed essenti~lly as in Example 1 by col.,bhling 5-octyl-2-(4-hydrophenyl)pyrimidine (1.02 g, 3.60 mmol) and 4-(2-(tridec~fluorohexyloxy)tetrafluoroethoxy)-2,2,3,3,4,4-heY~fll-orobutoxy) 1-bromobut~ne (3.03 g, 3.95 mmol; plepared from 1,4-dibromobut~ne and 4-(2-(trideç~fluorohexyloxy)tetrafluoroethoxy)-2,2,3,3,4,4-hexafluorobutanol). The resulting crude product was isolated and further purified ess~nti~lly as described in Example 3, eluting with 15 volume percent ethyl acetate/hexane, to yield 2.73 g of purified product.

ExamPle 37 Preparation of S-Hexyloxy-2-14-(4-(4-(2-(tridec~tluorohexyloxy)tetrafluoroethoxy)-~ ,4,4 he~atluorobutoxy)butoxy)phenyllpyrimidine The title compound was prepared ess~nfl~lly as in Example 1 by col.. bh~ g 5-hexyloxy-2-(4-hydrophenyl)pyrimidine (2.0 g, 7.3 mmol) and 4-(2-(tridec.~fluorohexyloxy)tetrafluoroethoxy)-2,2,3,3,4,4-hP~flllorobutoxy) l-bromobutane (6.1 g, 8.0 mmol, Example 36). The resulting crude product was isolated and filrther purified by Kugelrohr distillation (b.p. 210-220~C at 0.4 torr;
yield of 4.5 g). The distilled product was determined to be 96.7% pure by gas 20 chlol,.atographic analysis.

Example 38 ~r.ip&ration of 5-Octyl-2-[4-(3-(2,2,3,3,4,4,5,~6,6,6-I rsler~fluorohexyloxy)propoxy)phenyl]pyrimidine The title compound was prepared essenti~lly as in Example 1 by - co,nbi"ing 5-octyl-2-(4-hydrophenyl)pyridine (1.0 g, 3.52 mmol) and 3-(2,2,3,3,4,4,5,5,6,6,6-1lndec~flllorohexyloxy)-l-bromopropane (1.69 g, 4.01 mmol;
plepaled by co~.,bi";ng 1,3-dibromopropane with 2,2,3,3,4,4,5,5,6,6,6-undec-~fluorohexanol). The resulting crude product was isolated and further WO 97/13822 pcT/uss6lls76o purified ess~nti~lly as described in Example 3, eluting with 5 volume percent ethyl acetate/toluene, to yield 1.92 g of purified product.

ExamPle 39 Preparation of 5-Octyl-2-14-(6-(2,2,3,3,q"1,5,~,6~
undecafluorohe~ylo~y)hexylo~y)phenyl] pyrimidine The title compound was pl ~,pal ed ecsenti~lly as in Example 1 by cGlllbil-;llg 5-octyl-2-(4-hydroxyphenyl)py.i...;di..e (10.0 g, 35.2 rnmol) and 6-(2,2,3,3,4,4,5,5,6,6-undec~fl~lorohexyloxy)-l-bromohexane (17.1 g, 36.92 mmol;
prepared by combining 1,6-dibromohexane with 2,2,3,3,4,4,5,5,6,6,6-l~ndec~flllorohexanol). A~er refluxing overnight, toluene was added, and the resulting mixture was filtered. The resulting filtrate was concel~trated under reduced pressure, was washed with three 30 mL aliquots of perfluorohexane, was diluted with toluene, and was then again conce..ll ~ted under reduced pressure.
The resulting crude product was further purified by recryst~ tion from ethanol (yield of 17.3 g).

The compounds of Table 1 below were evaluated for transition te".pe~alLIres by d;~e,enlial sc~nning calorimetry (DSC) and/or optical observation of material phase changes using a ~.inl~h~m TMH600 hot stage and a polarizing microscope. The transition temperatures (~C) were obtained upon cooling through the isotropic state (I) to the smectic A mesophase (SA), the smectic C mesophase(Sc), and higher order mesophases (Ml and M2) or the crystalline state (K) and are set forth in the table. Using essenti~lly the method described below for Co.. "~a. ~ /e Example A, cone tilt angle was measured for some of the compounds shown in Table 1.

OD
- e U~ U~
~~: oo o V
o OD

~ O v~ ~

-~ o ~ ~ o~ ~ ~ ~
~J -o IL

o ~ r -- U~ Z~Z Z~Q~Z Z~Z Z~QZ Z~Z Z~Z

r. I~ _ ~ O
L) L L~L ' I T T

OD

", V V

o X ~ I~ X ~ ~ X

o ~ ~ _ ", _ X

b 3 ~, ~, 3 ~ T

E z x ~ ~ -- ~ ~ ~ ~

o~
--C~ m X
o .~ ~, x ~ ~, 8 J ~ J ~
cn Z~ Z ~ Z z~z o o ~ X ~ o ~ ~Z

r -~ ~ Ct~ X ~ ~
-~O \D X
o ~ ~ X ~ oo X 1--C~ o o ~ X ~ Cr~ X
o o~ _ o o ~ '~ -- ---- _ '3 0 S ~ ~ I ~ o o ~1 1: I I C.
~ O

o ~ u) ~ X O~ O --Z
~3 o~

-o ~ , ~ X

o '-- _ cn ~ o~
o X o~ ~ ~ ~ X C~

0 ~ ~

o ~;~ J

# Z ~ ~ 'O ~-- X c wO 97/13822 PCT/US96/15760 The data in Table 1 shows that most of the compounds exhibit smectic mesophases and that many of the compounds exhibit a broad smectic C
mesophase, which makes the compounds well-suited for use in liquid crystal display devices. As a result of the breadth of the smectic C mesophase, the compounds are useful in admixture with themselves or with other liquid crystal compounds, even at high concentration.

E~amples 40-54 describe liquid crystal compound mixtures and liquid clystal display devices according to the process of the invention.
In each of the following EY~mplçs and Co.--pa. ~ e Examples, liquid crystal compounds having high cone tilt angles were mixed with various concentrations of liquid crystal compounds having an extended hydrocarbon ether group ~jacent to a terminal fluorinated group and having low cone tilt angles (or latent low cone tilt angles), in order to demonstrate the ability of the latter compounds to provide mixtures having a reduced cone tilt angle relative to those of the former compounds. In these Examples, a mixture was prepared and placed into a glass ferroelectric liquid crystal (FLC) test cell having asymmetric alignmentlayers composed of, e.g., nylon faced with polysiloxane, essPnti~lly as described in U.S. Patent No. 5,377,033 (Radcliffe). The cell was placed on a microscope equipped with a hot stage and a photodetector/oscilloscope. The smectic A to C
transition temperature of the mixture was determined by heating the test cell to the smectic A phase of the mixture without an applied electric field (electrodes shorted), aligning the cell to obtain extinction between crossed polarizers, then slowly cooling and watching for a waveform shif't on the oscilloscope. The reduced te..,peralllre for each subsequent data point was calculated by subtracting the smectic A to C transition tel"?e,~tLlre from the hot stage temperature. Then a square wave signal was applied to the cell at a field of 12.5 V/micron, and cone tilt angle data was collected at each reduced te",pel ~Lure by measuring and averaging WO 97/13822 PCTtUS96/15760 the angle between "off' states (smectic C extinction) on either side of the smectic A
extinction angle. Cone tilt angle data was collected for each mixture at reducedte~ Jelatures of-1~C, -5~C, -10~C, -15~C, -20~C, -30~C, -40~C, and -50~C and is shown in Table 2 below. The .~.esophases of the mixtures were also determined 5 (essenti~lly as described above for individual compounds) and are shown in Table 3.

ComParati~e Example A
95 weight percent 5-octyloxy-2-[4-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)phenyl]pyrimidine (prepared essenti~lly as in Example 80 of U.S. Patent No. 5,437,812 (Janulis)) and 5 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine as a high polarization additive (which can be prepared ess~nti~lly as described below) were combined in a small vial at15 room temperature, and the resulting cobhldlion was heated to the isotropic state with manual roller mixing.

Preparation of 5-Octyl-2-14-((R)-2-fluoro-3-(2-(2-(~O''~t~l orobueoxy)tetranuoroethoxy)-2,2,-difluoroethoxy)propoxy)phenyllpyrimidine A solution of 5-octyl-2-[4-((S)-2-hydroxy-3-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,-difluoroethoxy)propoxy)phenyl]pyrimidine (prepared essenti~lly as described below, 8.0 g, 10.35 mmol) in dry tetrahydrofuran (50 ml) was added dropwise to a -70~C
solution of diethyl~minosl.lfilr trifluoride (3.3 g, 20.7 mmol) in tetrahydrofuran (S0 ml). The resulting mixture was warmed to -30~C over a period of 2 hours, and then pyridine (3.3 g, 41.4 mmol) was added to the mixture. The mixture was allowed towarm to ambient ten.pe.~ re and was stirred for 12 hours. The mixture was then poured into a slurry of silica gel (40 g) in diethyl ether and was concentrated onto the silica gel under reduced pressure. The product-coated silica was placed on top wO 97/13822 pcTluss6ll576o of 100 g offresh silica gel and was eluted with a 10:1 heY~nes/ethyl acetate solution Fractions collected cont~ining the product were conce..~ ed under reduced pressure. The product was then recryst~ ed from meth~nol to give 4.9 g of the title compound as a white solid.

Preparation of 5-Octy1-2-14-((S)-2-hydroxy-3-(2-(2-(nonailuorobutoxy)tetra~luoroethoxy)-2,2,-difluoroethoxy)propoxy)phenyl]pyrimidine A solution of potassium hydroxide (1.97 g, 35 mmol) in water (1.97 ml) was added to a solution of (S)-S-octyl-2-[4-(2,3-oxiranylpropoxy)phenyl]
pyrimidine (10.0 g, 29.3 mmol) (prepared ecsenti~lly as described by Sa~ çhi et al. in Ferroelectrics 114, 269 (1992)), 2,2-difluoro-2-[1,1,2,2-tetrafluoro-2-nonfluorobutoxy)ethanol] (15.2 g, 35.16 mmol), and tetrabutyl ammonium hydrogen sulfate (500 mg, 1.5 mmol) in tetrahydrofuran (20 ml). The resulting mixture was heated to reflux temperature for 23 hours, was diluted with water (100 ml), and was extracted with three 100 ml aliquots of ethyl acetate. The organic extracts were concen~ ed under reduced pressure, and the resulting product was recryst~lli7ed from acetonitrile (150 ml) to give -2-[4-((S)-2-hydroxy-3-(2-(2-(non~fl~lorobutoxy) 1,1,2,2-tetrafluoroethoxy)-2,2,-difluoroethoxy)propoxy)phenyl]-5-octyl-pyrimidine as a white solid.

E~ample 40 31.5 weight percent 5-octyl-2-[4-(6-(2-(nonafluorobutoxy)-2,2-difluoroethoxy)hexyloxy)phenyl]pyrimidine (Example 34), 63.6 weight percent 5-octyloxy-2-[4-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)phenyl]pyrimidine, and 4.9 weight percent 5-octyl-2-[4-((R)-2-fluoro-3 -(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined essenfl~lly as described in Con.;)a.~ e Example A.

E~ample 41 47.5 weight percent 5-octyl-2-[4-(6-(2-(nonafluorobutoxy)-2,2-difluoroethoxy)hexyloxy)phenyl]pyrimidine (Example 34), 47.8 weight percent 5-octyloxy-2-[4-(2-(2-(non~fluorobutoxy)tetrafluoroethoxy)-5 2,2- difluoroethoxy)phenyl]pyrimidine, and 5.2 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)p~opo~y)phenyl]pyrimidine (as a high polarization additive) were col..b.-.ed essenti~lly as described in Co,..pa.dlive Example A.

10 Example 42 31.8 weight percent 5-hexyloxy-2-[4-(4-(2-(2-(pentafluoroethoxy)tetrafluoroethoxy) 2,2-difluoroethoxy)butoxy)phenyl]pyrimidine (Example 21), 63.2 weight percent 5-octyloxy-2-[4-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-lS 2,2- difluoroethoxy)phenyl]pyrimidine, and 4.9 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined essential1y as described in Comparative Example A.

20 E~ample 43 47.4 weight percent 5-hexyloxy-2-[4-(4-(2-(2-(pent~fluoroethoxy)tetrafluoroethoxy) 2,2-difluoroethoxy)butoxy)phenyl]pyrimidine (Example 21), 47.7 weight percent 5-octyloxy-2-[4-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-25 2,2- difluoroethoxy)phenyl]pyrimidine, and 5.0 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were co",bi"ed ~ossent~ y as described in Co",l)a~ e Example A.

E~ample 44 31.7 weight percent 5-octyl-2-[4-(6-(2-(2-S (non~fluorobutoxy)tetrafluoroethoxy) 2,2 difluoroethoxy)hexyloxy)phenyl]pyrimidine (Example 4), 63.4 weight percent 5-octyloxy-2-[4-(2-(2-(non~fluQrobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)phenyl]pyrimidine, and 4.9 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-1 0 (nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined Pssenti~lly as described in Co".pa,alive Example A.

E~ample 45 47.4 weight percent 5-octyl-2-[4-(6-(2-(2-1 5 (nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)hexyloxy)phenyl]pyrimidine (Example 4), 47.4 weight percent 5-octyloxy-2-[4-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)phenyl]pyrimidine, and 5.2 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined essenti~lly as described in Co"")ala~ e Example A.

Example 46 47.4 weight percent 5-octyl-2-[4-(4-(4-(2-(tridecafluorohexyloxy)tetrafluoroethoxy)-2,2,3,3,4,4-hPY~fluorobutoxy)butoxy)phenyl]pyrimidine (Example 36) 47.5 weight percent 5-octyloxy-2-[4-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)phenyl]pyrimidine, and 5.2 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined çss~nti~lly as described in Cor..par~ re Fx~mple A.
S
Comparative Examp1e B
95 weight percent 5-octyl-2-[4-(6-(2-(2-(2-(trifluorolnethoxy)tetrafluoroethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6-decafluorohexyloxy)phenyl]pyrimidine (p.e"a-~d essenti~lly as in 10 Example 110 of U.S.S.N 08/3389S7) and 5 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined e~enti~lly as described in Co...pa. ~ti~/e Example A
Example 47 47 4 weight percent 5-octyl-2-[4-(4-(4-(2-(tridecafluorohexyloxy)tetrafluoroethoxy)-2,2,3 ,3 ,4,4-hexafluorobutoxy)butoxy)phenyl]pyrimidine (Example 36), 47.5 weight percent 5-octyl-2-[4-(6-(2-(2-(2-(trifluo. o...elhoxy)tetrafluoroethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6-decafluorohexyloxy)phenyl]pyrimidine, and 5.2 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-25 difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined essentially as described in Comparative Example A

ComParative Example C
47.4 weight percent 5-octyl-2-[4-(6-(2-(nonafluorobutoxy)-2,2-30 difluoroethoxy)hexyloxy)phenyl]pyrimidine (Example 34), 47.4 weight percent 5-octyl-2-[4-(6-(2-(2-(2-(trifluo. Ul~ ,elhoxy)tetrafluoroethoxy)tetrafluoroethoxy)tetrafluoroethoxy) 2,2,3,3,4,4,5,5,6,6-deç~fluQrohexyloxy)phenyl]pyrimidine, and 5.1 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-5 (nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were cG..,b;"ed e~enti~lly as described in Co.--?a.~live Example A.
Due to concentration effects, the resulting cG~Ibh~alion yielded no smectic A to smectic C transition te.~.pel ~ re, and the tilt angle of the mixture 10 could not be measured.

ComParative Example D
47.5 weight percent 5-octyl-2-[4-(6-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-15 difluoroethoxy)hexyloxy)phenyl]pyrimidine (Example 4), 47.5 weight percent 5-octyl-2-[4-(6-(2-(2-(2-(trifluoromethoxy)tetrafluoroethoxy)tetrafluoroethoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6-dec~fluorohexyloxy)phenyl]pyrimidine, and 4 9 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-20 (nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined ecsenti~lly as described in Co,..pa-~live Example A
Due to conce.-l-~ion effects, the resulting co.,.binalion yielded no smectic A to smectic C transition temperature, and the tilt angle of the mixture25 could not be measured.

Comparative Example E
95 weight percent 5-octyl-2-[4-(10-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9, 10, 10-oct~ec~fluorodecyloxy)phenyl~pyrimidine (pl e~)ared ess~nti~lly as in Example 111 of U.S.S.N. 08/338957) and 5 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were 5 cG...bined eSspnti~lly as described in Con~p~-ali~re Example A.

Example 48 47.6 weight percent 5-octyl-2-[4-(4-(4-(2-(tridec~fluorohexyloxy)tetrafluoroethoxy)-2,2,3 ,3 ,4,4-10 hexafluorobutoxy)butoxy)phenyl]pyrimidine (Example 36),47.4 weight percent 5-octyl-2-[4-(10-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,1 0-oct~dec~fluorodecyloxy)phenyl]pyrimidine (p~epaled eesenti~lly as in Example 101 of U.S.S.N. 08/338957), and 5.0 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-15 2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were con-b;ned ÇcS~nti~lly as described in Comparative Example A.

E~ample 49 47.5 weight percent 5-octyl-2-[4-(6-(2-(nonafluorobutoxy)-2,2-20 difluoroethoxy)hexyloxy)phenyl]pyrimidine (Example 34),47.3 weight percent 5-octyl-2-[4-(10-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9, 10, 10-octadecafluorodecyloxy)phenyl]pyrimidine, and 5.2 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-25 (nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined çseçnti~lly as described in Col~par~ e Example A.

WO 97/13822 PCTtUS96/15760 Example 50 47.5 weight percent 5-octyl-2-[4-(6-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)hexyloxy)phenyl]pyrimidine (FY~mple 4), 47.7 weight percent 5-octyl-2-[4-(10-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-oct~dec-~fluorodecyloxy)phenyl]pyrimidine,and 4.8 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined eSspnti~lly as described in Con.pal ~ e Example A.

Comparative Example F
95 weight percent 5-octyl-2-[4-(4-(2-(tridec~fluorohexyloxy)tetrafluoroethoxy)-2,2,3,3,4,4-hexafluorobutoxy)phenyl]pyrimidine (prepared éssenti~lly as in Example 116 of U.S.S.N. 08/338957) and 5 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)plopoxy)phenyl]pyrimidine (as a high polarization additive) were combined essenti~lly as described in Colll~,ala~ e Example A.

Example ~1 47.5 weight percent 5-octyl-2-[4-(4-(4-(2-(trirler~flllorohexyloxy)tetrafluoroethoxy)-2,2,3,3,4,4-hexafluorobutoxy)butoxy)phenyl]pyrimidine (Example 36), 47.3 weight percent 5-octyl-2-[4-(4-(2-(tridec~fluorohexyloxy)tetrafluoroethoxy)-2,2,3,3,4,4-hexafluorobutoxy)phenyl]pyrimidine, and 5.1 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were co-,.bined essenti~lly as described in Comparative Fy~rnrle A.

ComParative Example G
47.3 weight percent 5-octyl-2-[4-(6-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)hexyloxy)phenyl]pyrimidine (Example 4), 47.5 weight percent 5-octyl-2-[4-(4-(2-(tridecafluorohexyloxy)tetrafluoroethoxy)-2,2,3,3,4,4-hPx~fl-lorobutoxy)phenyl]pyrimidine, and S.2 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined essçnfl~lly as described in Col"paldlive Example A.
Due to concenl . ~lion effects, the resulting colllbil,alion yielded no smectic A to smectic C transition temperature, and the tilt angle of the mixturecould not be measured.

Comparative Example ~I
95 weight percent 5-octyl-2-[4-(6-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3 ,3 ,4,4, 5,5,6,6-dec~fl~lorohexyloxy)phenyl]pyrimidine (plepared essPnti~lly as in Example 99 of U.S.S.N. 08/338957) and 5 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)ylopoxy)phenyl]pyrimidine (as a high polarization additive) were combined essenti~lly as described in Comparative Example A.
Example 52 47.4 weight percent 5-octyl-2-[4-(4-(4-(2-(tridec~flllorohexyloxy)tetrafluoroethoxy)-2,2,3,3 ,4,4-h~Y~fluorobutoxy)butoxy)phenyl]pyrimidine (Example 36), WO 97/13822 PCT/US96/lS760 - 47.5 weight percent 5-octyl-2-[4-(6-t2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6-decafluorohexyloxy)phenyl]pyrimidine (prepalt:d essenti~lly as in Example 107 of U.S.S.N. 08/338957), and 5.2 weight percent 5-octyl-2-[4-((R)-2-fluoro-3 -(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-S difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined escenti~lly as described in Comparative Example A.

Comparative Example I
47.5 weight percent 5-octyl-2-[4-(6-(2-(non~flllorobutoxy)-2,2-difluoroethoxy)hexyloxy)phenyl]pyrimidine (Example 34), 47.4 weight percent 5-octyl-2-[4-(6-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6-dec~fluorohexyloxy)phenyl]pyrimidine, and 5.0 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined essentially as described in Comparative Example A.
Due to concentration effects, the resulting combination yielded no smectic A to smectic C transition temperature, and the tilt angle of the mixturecould not be measured.

Comparative Example J
47.4 weight percent 5-octyl-2-[4-(6-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)hexyloxy)phenyl]pyrimidine (Example 4), 47.3 weight percent 5-octyl-2-[4-(6-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2,3,3,4,4,5,5,6,6-decafluorohexyloxy)phenyl]pyrimidine, and 5.4 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined eccenti~lly as described in Comparative Example A

Wo 97/13822 PCT/US96/15760 Due to concentration effects, the resulting co,.,binalion yielded no smectic A to smectic C transition temperature, and the tilt angle of the mixturecould not be measured.

5 Comparative Example K
95 weight percent 5-octyl-2-[4-(6-(2-(2-(non~fluorobutoxy)tetrafluoroethoxy)tetrafluoroethoxy-2,2,3,3,4,4,5,5,6,6-dec~fluQrohexyloxy)phenyl]pyrimidine (plepa-ed ess~nfl~lly as in Example 104 of U.S.S.N. 08/338957) and 5 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-l 0 (nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined essenti~lly as described in Co",?a,~live Example A

Example 53 47.4 weight percent 5-octyl-2-[4-(4-(4-(2-(tridec~flnQrohexyloxy)tetrafluoroethoxy)-2,2,3,3,4,4-h~x~flllorobutoxy)butoxy)phenyl]pyrimidine (Example 36), 47.5 weight percent 5-octyl-2-[4-(6-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)tetrafluoroethoxy-2,2,3,3,4,4,5,5,6,6-dec~fluQrohexyloxy)phenyl]pyrimidine (plepa,t;d essenti~lly as in Example 104 ofU.S.S.N. 08/338957), and 5.2 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy),~opo~y)phenyl]pyrimidine (as a high polarization additive) were combined e~senti~lly as described in Co,l")a~ /e Example A.
Comparative Example L
47.7 weight percent 5-octyl-2-[4-(6-(2-(nonafluorobutoxy)-2,2-difluoroethoxy)hexyloxy)phenyl]pyrimidine (Example 34), 47.3 weight percent 5-octyl-2-[4-(6-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)tetrafluoroethoxy-2,2,3,3,4,4,5,5,6,6-wO 97/13822 PCT/US96/15760 dec~fluorohexyloxy)phenyl]pyrimidine, and 5.2 weight percent 5-octyl-2-[4-((R)-2-fluoro-3 -(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined eSsçnti~lly as described in Co-"pa-d~ e Example A.
Due to concenl. ~Lion effects, the resulting co..... l)inalion yielded no smectic A to smectic C transition temperature, and the tilt angle of the mixturecould not be measured.

Comparative Example M
47.7 weight percent 5-octyl-2-[4-(6-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)hexyloxy)phenyl]pyrimidine (Example 4), 47.4 weight percent 5-octyl-2-[4-(6-(2-(2-(non~fluorobutoxy)tetrafluoroethoxy)tetrafluoroethoxy-2,2,3 ,3 ,4,4,5,5,6,6-dec~fluorohexyloxy)phenyl]pyrimidine, and 4 9 weight percent 5-octyl-2-[4-((R)-2-fluoro-3 -(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined essenfl~lly as described in Co.-.pa.~ e Example A.
Due to concentration effects, the resulting co-.lbinalion yielded no 20 smectic A to smectic C transition temperature, and the tilt angle of the mixture could not be measured Comparative Example N
47 5 weight percent 5-octyl-2-[4-(4-(2-25 (nonafluorobutoxy)tetrafluoroethoxy)-4,4-difluorobutoxy)phenyl]pyrimidine (prepared eSspnti~lly as in Example 114 of U S S N 08/338957 using 4,4-difluoro-4(perfluorobutoxyethoxy)-butanol), 47.7 weight percent 5-octyloxy-2-[4-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)phenyl]pyrimidine, and 5.2 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoro~lhoxy),uropoA.~)phenyl]pyrimidine (as a high polarization additive) were cG."~i..ed ess~nti~lly as described in Cor..pa.~ re Example A.

Comparative Example O
47.5 weight percent 5-octyl-2-[4-(5-(2-(nonqfluorobutoxy)tetrafluoroethoxy)-5,5-difluoropentoxy)phenyl]pyrimidine (p.~pa.ed eSsenti~lly as in Example 114 of U.S.S.N. 08/338957), 47.7 weight percent 5-octyloxy-2-[4-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)phenyl]pyrimidine, and 5.2 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were 15 cGbined essenti~lly as described in Con.~a.~live Example A.

ComParative Example P
47.5 weight percent 5-octyl-2-[4-(10-(2-(nonqfluorobutoxy)tetrafluoroethoxy)-i,4,5,5,6,6,7,7,8,8-dec~fl-lorooctyloxy)phenyl]pyrimidine (pl epa. ed essenti~lly as in Example 115 of U.S.S.N 08t338957), 47.7 weight percent 5-octyloxy-2-[4-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)phenyl]pyrimidine, and 5.2 weight percent 5-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were combined eCcenti~lly as described in Col,.pa,~live Example A.

ExamPle 54 47.6 weight percent 5-octyl-2-(4-(2-(2-(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-W O 97/13822 rCT~US96/15760 p~nt~dec~fl~lorooctyloxy)ethoxy)ethoxy)phenyl)pyrimidine (prel)aled ess-onti~lly as in Example 75 of U.S. Patent No. 5,437,812), 47.6 weight percent 5-octyloxy-2-[4-(2-(2-(nonafluorobutoxy)tetrafluoroethoxy)-2,2- difluoroethoxy)phenyl]pyrimidine, and 4.9 weight percent S-octyl-2-[4-((R)-2-fluoro-3-(2-(2-(nonfluorobutoxy)tetrafluoroethoxy)-2,2-difluoroethoxy)propoxy)phenyl]pyrimidine (as a high polarization additive) were co-n~;ned e~nti~lly as described in Co,,li)arali~e Example A.

Table 2. Cone Tilt Angles (Degrees) Reduced Temperature (~C) F.Y~PIe -1 -5 -10 -15 -20 -30 -40 -S0 NO.
Comp.A 10 26.5 31.2 32.5 34.5 33.S
16.0 21.5 25.5 26.0 27.5 27.5 27.5 27.5 41 10.5 15.5 18.0 19.5 20.5 20.5 20.5 42 15.5 22.5 25.5 26.0 26.5 26.5 28.5 28.5 43 13.0 16.0 18.0 19.5 21.5 21.5 21.5 21.5 44 18.0 24.5 26.5 27.5 27.5 27.5 29.5 29.5 13.0 17.5 19.5 22.0 22.5 24.0 24.0 24.0 46 18.5 23.0 23.25 23.5 25.0 25.25 26.0 25.5 Comp. B 21.5 25.25 23.25 27.5 27.65 29.0 30.5 47 9.5 15.5 18.0 20.0 21.0 21.5 21.5 Comp. E 12.6 20.9 27.9 30.75 31.25 48 11.0 19.0 24.0 26.5 28.0 30.0 31.5 31.5 49 12.5 15.0 17.0 17.5 17.5 18.0 18.0 17.0 22.0 24.5 25.0 26.5 26.5 26.5 26.5 Comp. F 18.0 25.0 26.0 28.5 29.5 29.5 29.5 29.5 51 14.5 16.0 18.5 18.5 18.5 18.5 Comp. H 18.5 23.25 25.75 26.75 27.5 28.25 29.0 WO 97/13822 PCTtUS96tlS760 Reduced Temperature (~C) E;xample -1 -5 -10 -15 -20 -30 -40 -50 No.
52 11.0 16.5 16.5 18.5 18.5 18.5 18.5 53 18.5 21.5 15.3 25.0 25.0 26.0 26.0 54 14.0 20.0 23.25 24.0 25.0 25.5 Comp. K 29.0 30.5 31.8 Comp. N 22.0 26.0 27.5 31.5 32.5 31.0 32.5 32.5 Comp. O 15.0 20.5 23.5 24.5 25.5 25.5 27.5 27.5 Comp. P 12.5 25.5 29.5 32.5 33.0 33.5 33.5 33.5 Table 3. Transition Temperatures (~C) Example No. I to A A to C C to K
Comp.A 95 83 47 101.8 74.4 8.6 41 103.0 62.6 <-10 42 120.9 85.2 -2.7 43 126.5 78.5 clo 44 104.4 75.4 6.8 106.9 66.g <-15 46 109.9 69.0 -8.7 Comp.B 113.3 64.8 -31 47 118.6 58.0 <-10 Comp.C 109.8 none <-10 Comp.D 114.8 none <-10 Comp.E 121.6 85.2 26.8 48 124.1 82.7 <-10 49 115.7 58.8 <-10 120.1 76.8 <-10 Comp.F 95.1 52.7 2.9 Sl 109.4 48.4 <-10 Comp.G 108.8 none <-10 Comp.H 115.6 65.4 <-10 52 118.8 56.7 <-10 Comp.I 108.8 none <-10 Comp.J 112.2 none ~-10 Comp.K 112 63 -14 53 118.0 62.0 <-10 Comp.L 110.4 none <-10 Comp.M 112.3 none <-10 Example No. I to AA to C C to K
Comp. N 96.9 76.2 13.6 Comp. O 104.367.9 -3.5 Comp. P 118.882.7 9.4 54 96.5 65.7 11.5 The data in Table 2 shows that the liquid crystal compound mixtures of the Co~,lparali~e Examples (hereinafter, the co",pa,~Li.~e mixtures) had cone tilt angles generally in excess of the ideal 22.5 degrees. When liquid crystal compounds 5 of Formula I, supra, were added to the co-"pa-ative mixtures, the cone tilt angles of the mixtures were reduced, as shown by the following comparisons:
Comparative Example A / Examples 40-46 and 54 Comparative Example B / Example 47 Comparative Example E / Examples 48-50 Comparative Example F / Example 51 Comparative Example H / Example 52 Corl")ar~Li~e E~al"ples N, O, and P showed the effect of the addition (to base mixtures) of liquid crystal compounds which did not possess an extended hydrocarbon ether group adjacent to a terminal fluorinated group. Such 15 compounds were not as effective in !educing tilt angle while substantially ll~h;~ l;ng the tilted smectic mesophase of the base mixture as were compounds which did possess such an extended group (see, e.g., Examples 41, 45, and 46).
The data in Table 3 shows that the above-described liquid crystal compounds (which do possess an extended hydrocarbon ether group a~jac~nt to a 20 terminal fluorinated group), when used in base mixtures according to the process of the invention, advantageously produce a relatively low suppression (and, in somecases, even a bro~lçning) of the smectic C mesophase of the base mixtures.

WO 97/13822 pcTluss6lls76o Various modifications and alterations of this invention will become appare.lt to those skilled in the art without departing from the scope and spirit of this invention.

Claims (11)

Claims

1. A process for controlling the cone tilt angle of a tilted smectic liquid crystal composition comprising the step of combining (a) at least one liquid crystal composition comprising at least one smectic or latent smectic liquid crystal compound comprising (i) an aliphatic fluorocarbon terminal portion comprising a terminal group and an alkylene group having at least two carbon atoms and containing at least one catenary ether oxygen atom, (ii) an aliphatic hydrocarbon terminal portion, and (iii) a central core connecting saidterminal portions; and (b) at least one liquid crystal composition comprising at least one smectic or latent smectic liquid crystal compound; with the provisos that atleast one of said compositions (a) and (b) comprises at least one chiral liquid crystal compound and that said combining of compositions (a) and (b) provides an optically active, tilted chiral smectic liquid crystal composition.

2. The process of Claim 1 wherein said aliphatic fluorocarbon terminal portion is represented by the formula -D-Rh-Rf, where Rh is an alkylenegroup having at least two carbon atoms and containing at least one catenary ether oxygen atom; Rf is; and D is non-directionally selected from the group consisting of a covalent bond, -C(=O)O-CrH2r, -O-CrH2r-, -O(C~H2~O)tCrH2r-, -CrH2r-, (CsH2sO)tCrH2r-, -OSO2-, -SO2-, -SO2-CrH2r-, , -C(=O)-, -O(O=)C-CH2,-CH2-N-C(=O)-,CH=N, -O-, -S-,-N(CpH2p+1)-, and combinations thereof, where r and r' are independently integers of 0 to about 20, s is independently an integer of 1 to about 10 for each (C,H2,O), t is an integer of 1 to about 6, and p is an integer of 0 to about 4>

3. The process of Claim 1 wherein said smectic or latent smectic liquid crystal compound of said composition (a) is represented by the general formula I:

where M, N, and P are each independently selected from the group consisting of , and , and , , and a, b, and c are each independently zero or an integer of from 1 to 3, with the proviso that the sum of a + b + c be at least 1;

each A and B are non-directionally and independently selected from the group consisting of a covalent bond, -C(=O)-O-, -C(=O)-S-, -C(=O)-Se-, -C(=O)-Te-, -(CH2CH2)k- where k is 1 to 4, -CH=CH-, -C=C-, -CH=N-, -CH2-O-, -C(=O)-, and-O-;

each X, Y, and Z are independently selected from the group consisting of-H, -C~,-F,-Br, -~,-OH, -OCH3, -CH3, -CF3, -OCF3, -CN, and-NO2, each ~, m, and n are independently zero or an integer of 1 to 4;

D is non-directionally selected from the group consisting of a covalent bond, -C(=O)-O-CrH2r-,-O-CrH2r-,-O-(O=)C-CrH2r-,-C~C-,-CH=CH-,-C(=O)-, -O(CsH2sO)1CrH2r-,CrH2r-,(C3H2sO)1CrH2r-,-O-,-S-, -OSO2-,-SO2-,-SO2CrH2R-,,-N(CpH2p+1)-, -CH=N-, and combinations thereof, where r and r' are independently integers of 0 to about 20, s is independently an integer of 1 to about 10 for each (CsH2sO), t is an integer of 1 to about 6, and p is an integer of 0 to about 4;

R is selected from the group consisting of -O-((Cq' H2q'-v-(R')v)-O)w-CqH2q+1-v-(R)v, -((CqH2q'-v-(R)v)-O)w-CqH2q+1-v-(R')v, -C(=O)-O-CqH2q+1-v-(R')v, -O-(O=)C-CqH2q+1-v-(R')v, , and -CR'H-(D)g-CR' H-CqH2q+1v-(R')v, where each R' is independently selected from the group consisting of-Cl, -F, -CF3, -NO2, -CN, -H, -CqH2q+1, -O-(O=)C-CqH2q+1, -C(=O)-O-CqH2q+1, -Br, -OH, and -OCqH2q+1, q' is independently an integer of 1 to about 20 for each (Cq'H2q'-O); q is an integer of 1 to about 20; w is an integer of 0 to about 10; v is an integer of 0 to about 6; each v' is independently an integer of 0 to about 6; g is an integer of 1 to about 3; each D is independently and non-directionally selected from the group set forth for D above, with the proviso that the ring containing D has from about 3 to about 10 ring atoms; each W is independently selected from the group consisting of N,CR', and SiR';

Rh is an alkylene group having at least two carbon atoms and containing at leastone catenary ether oxygen atom; and Rf is perfluoroether.

4. A process for controlling the cone tilt angle of a tilted smectic liquid crystal composition comprising the step of combining (a) at least one liquid crystal composition comprising at least one smectic or latent smectic liquid crystal compound comprising (i) an aliphatic fluorocarbon terminal portion represented by the formula -D-Rh-Rf, where Rh contains from 2 to about 12 carbon atoms and is represented by the general formula (CsH2sO)tCr'H2r'-, wherein s is independently an integer of 1 to about 10 for each (C,H2,O), t is an integer of 1 to about 6, and r' is an integer of 1 to about 10; Rf is, perfluoroether and contains from 1 to about 20 carbon atoms; and D is selected from the group consisting of-O-, -C(=O)-, a covalent bond, and combinations thereof; (ii) an aliphatic hydrocarbon terminal portion; and (iii) a central core connecting said terminal portions; and (b) at least one liquid crystal composition comprising at least one fluorine-containing, smectic or latent smectic liquid crystal compound; with theprovisos that at least one of said compositions (a) and (b) comprises at least one chiral liquid crystal compound and that said combining of compositions (a) and (b) provides an optically active, tilted chiral smectic liquid crystal composition.

5. Fluorine-containing liquid crystal compounds represented by the general formula I:

where M, N, P, A, B, X, Y, Z, a, b, c, l, m, n, D, and R are as defined in Claim 3;
Rh is represented by the directional general formula (-C,H2,O-)~Cr~H22r-, wherein s is independently an integer of 2 to about 10 for each (CsH2sO), t is an integer of 1 to about 6, and r' is an integer of 1 to about 10; and Rf is perfluoroether;
with the proviso that the compounds exhibit at least one tilted smectic mesophase.

6. Fluorine-containing liquid crystal compounds represented by the general formula I:

where M is pyrimidine; N is phenyl; A is a covalent bond; X and Y hydrogen; a and b are integers of 1;1 is an integer of 2; m is an integer of 4; D is -O-; R is an alkyl, fluoroalkyl, alkoxy, or fluoroalkoxy group having from about 4 to about 8 carbonatoms and optionally containing one or more catenary ether oxygen atoms; Rh has from about 4 to about 8 carbon atoms and is represented by the directional general formula (CsH2sO-)~Cr~H2r-, wherein s is independently an integer of 3 to about 7 for each (-CsH2sO), t is an integer of 1 to 2, and r' is an integer of 1; and Rf is a perfluoroether group represented by the formula -(CxF2xO)zCyF2y+1, where x is independently an integer of 1 to about 10 for each(CxF2x,O), y is an integer of 1 to about 10, and z is an integer of 1 to about 10; with the proviso that the compounds exhibit at least one tilted smectic mesophase.

7. Fluorine-containing liquid crystal compounds represented by the general formula I:

where M, N, P, A, B, X, Y, Z, a, b, c, l, m, n, D, and R are as defined in Claim 3;
Rh is represented by the directional general formula (-CsH2sO-)tCr~H2r-, wherein s is independently an integer of 3 to about 10 for each (CsH2s,O), t is an integer of 1 to about 6, and r' is an integer of 1 to about 10; and Rf is perfluoroether;
with the proviso that the compounds do not exhibit at least one tilted smectic mesophase.

8. Fluorine-containing liquid crystal compounds represented by the general formula I:

where M is pyrimidine; N is phenyl; A is a covalent bond; X and Y hydrogen; a and b are integers of 1;1 is an integer of 2; m is an integer of 4; D is -O-; R is an alkyl, fluoroalkyl, alkoxy, or fluoroalkoxy group having from about 4 to about 8 carbonatoms and optionally containing one or more catenary ether oxygen atoms; Rh has from about 4 to about 8 carbon atoms and is represented by the directional general formula (-CsH2sO-)tCr~H2r-, wherein s is independently an integer of 3 to about 7 for each (CsH2sO), t is an integer of 1 to 2, and r' is an integer of 1; and Rf is a perfluoroether group represented by the formula -(CxF2xO)2CyF2y+1, where x is independently an integer of 1 to about 10 for each (CxF2xO), y is an integer of 1 to about 10, and z is an integer of 1 to about 10; with the proviso that the compounds do not exhibit at least one tilted smectic mesophase.

9. A mixture of liquid crystal compounds prepared by the process of Claim 1, wherein said alkylene group has at least 4 carbon atoms.

10. A mixture of liquid crystal compounds comprising at least one compound of Claim 5 or Claim 7.

11. A liquid crystal display device containing the mixture of Claim 9 or Claim 10.