JP2007223950A - 1,3-dioxane ring-containing ester compound, composition comprising the compound, retardation film and display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a compound having a high dielectric anisotropy ▵ε. <P>SOLUTION: The compound is represented by general formula (A-1) (R<SP>1</SP>, R<SP>2</SP>and X<SP>1</SP>-X<SP>12</SP>are each independently a hydrogen atom or a substituted group; A is a six-membered ring or a polycyclic condensed ring constituted of at least one six-membered ring; m is 1 or 2; L is any one connecting group represented by general formula (A-II)). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ester compound having a 1,3-dioxane ring, and particularly to a compound that can be suitably used for a liquid crystal composition, a retardation plate, and a display device.

Liquid crystals (compounds) are widely used in applications such as devices such as displays and optical elements such as retardation plates, and development of new materials according to the purpose is desired. The types of liquid crystals known so far include nematic liquid crystals, cholesteric liquid crystals, smectic liquid crystals, and discotic liquid crystals, and various liquid crystal display elements have been put to practical use by utilizing the electro-optic effect unique to each liquid crystal. .
Among these liquid crystals, liquid crystal display elements using nematic liquid crystals are particularly widely used. The display methods include dynamic scattering, birefringence control, guest / host, and twisted nematic (TN). In addition, there are a super twist nematic type (STN type), a super twist birefringence type, etc., and there are a static drive method, a time division drive method, an active matrix drive method, a dual frequency drive method, and the like.

  Liquid crystals must have good chemical stability and stability to heat, and good stability to electric fields and electromagnetic radiation. Furthermore, the liquid crystal material preferably has a low viscosity from the viewpoint of driving speed, and must exhibit a short address time, a low threshold voltage and a large contrast in the cell.

The threshold voltage (Vth) is a function of dielectric anisotropy (Δε) as expressed by the following equation (Mol. Cryst. Liq. Cryst., 12, 57 (1970)).
Vth = π {K / (ε ₀ × Δε)] ^1/2
In the above equation, K represents an elastic constant, and ε ₀ represents the dielectric constant of vacuum.

  As can be seen from this equation, in order to reduce the threshold voltage (Vth), two methods of increasing the dielectric anisotropy (Δε) or decreasing the elastic constant K are conceivable. . However, since it is difficult to control the elastic constant K with the existing technology, the requirement for a low threshold voltage is addressed by using a material having a large dielectric anisotropy (Δε). For this reason, liquid crystal compounds having a large dielectric anisotropy (Δε) are being actively developed.

Under such circumstances, for example, a 1,3-dioxane derivative is disclosed as a liquid crystal material having a positive dielectric anisotropy (see, for example, Patent Document 1).
International Publication No. 01/027221 A1 Brochure

  An object of the present invention is to provide a compound having a large value of dielectric anisotropy Δε.

  The above object of the present invention has been achieved by the following constitution.

<1> A compound represented by the following general formula (AI).

In general formula (AI), R ¹ , R ² , and X ^{1 to} X ⁶ each independently represent a hydrogen atom or a substituent, and L is any of the following general formula (A-II) Represents one linking group, and A represents a 6-membered ring or a polycyclic fused ring composed of at least one 6-membered ring. M represents 1 or 2.

<2> The compound according to <1>, wherein the linking group represented by L is —COO—.

<3> The compound according to <1> or <2>, wherein X ^{2 to} X ⁶ in the general formula (AI) are hydrogen atoms.

<4> Any one of the above <1> to <3>, wherein when A in the general formula (AI) is a 6-membered ring, it is a 6-membered ring having a bonding position at the 1,4-position The compound according to item 1.

一般式（Ｂ−Ｉ）〜（Ｂ−Ｖ）中、Ｒ¹、Ｒ²、Ｒ³及びＸ¹は、各々独立に、水素原子又は置換基を表し、Ｌは前記一般式（Ａ−ＩＩ）で表されるいずれか１つの連結基を表す。 <5> The compound represented by the general formula (AI) is a compound represented by the following general formulas (BI) to (BV): Compound.

In the general formulas (BI) to (BV), R ¹ , R ² , R ³ and X ¹ each independently represent a hydrogen atom or a substituent, and L represents the general formula (A-II). Any one linking group represented by the formula:

<6> In the general formula (AI), when A is a bicyclo group composed of a 6-membered ring, it is a bicyclo group having a bonding position at positions 3 and 8, <1> to < 3. The compound according to any one of 3>.

<7> A composition containing at least one compound according to any one of <1> to <6>.

<8> A retardation plate having a transparent support and at least one optically anisotropic layer containing the composition according to <7> on the transparent support.

<9> A display device having a pair of electrode substrates and a liquid crystal layer containing the composition according to <7> between the pair of electrode substrates.

  According to the present invention, a compound and a composition having a large dielectric anisotropy Δε can be provided, and a retardation plate and a display device having a small threshold voltage (Vth) can be provided.

1. Compound represented by general formula (AI) First, the structure of a compound represented by general formula (AI) (hereinafter, referred to as “the compound of the present invention” as appropriate) and dielectric anisotropy Δ The relationship of ε will be described.
The dielectric anisotropy (Δε) represents the difference between the dielectric constant in the direction parallel to the molecular orientation direction and the dielectric constant in the vertical direction, and is represented by the following formula.
Dielectric anisotropy (Δε) = ε‖−ε⊥

  In the above formula, ε‖ represents a dielectric constant in a direction parallel to the direction of molecular orientation, and ε⊥ represents a dielectric constant in a perpendicular direction. That is, in order to increase the dielectric anisotropy (Δε), it is effective to increase the polarization in the major axis direction in the molecule of the rod-like liquid crystal compound.

  Here, the compounds represented by the general formula (AI) of the present invention are as follows.

In General Formula (AI), R ¹ , R ² , and X ^{1 to} X ⁶ each independently represent a hydrogen atom or a substituent, and L is a linkage represented by General Formula (A-II) below. Represents a group, and A represents a 6-membered ring or a polycyclic fused ring composed of at least one 6-membered ring. M represents 1 or 2.

  In the compound represented by the general formula (AI), the dipole of the 1,3-dioxane group is parallel to the molecular long axis. Further, the ester group adjacent to the 1,3-dioxane group increases the dielectric constant in the molecular long axis direction.

  Further, when A in the general formula (AI) is not cyclic, the compound represented by the general formula (AI) does not exhibit liquid crystallinity and is composed of a 6-membered ring or at least one 6-membered ring. When the polycyclic fused ring is not used, the linearity of the molecule is lowered, and the dielectric constant in the molecular major axis direction is lowered. Moreover, a preferable liquid crystal phase is not taken. This is shown below.

  As shown in the following structural formula (I-1), when A is a 6-membered aliphatic ring having a bonding position at positions 1 and 4 (trans type), the compound represented by the general formula (AI) The joint extends in the long axis direction.

  On the other hand, for example, when A is a 5-membered aliphatic ring, the compound represented by the general formula (AI) at the position of the 5-membered aliphatic ring is represented by the structural formula (II-1). The shape is bent. Accordingly, the dielectric constant in the molecular long axis direction is lowered.

  Further, as shown in the following structural formula (III), when A is a 6-membered aromatic ring having a bonding position at positions 1 and 4, in the long axis direction of the compound represented by the general formula (AI) The bond is extended. On the other hand, for example, when A is a 5-membered aromatic ring, with respect to the long axis direction of the compound represented by the general formula (AI) at the position A as shown in the following structural formula (IV) At least 36 ° will be refracted. Therefore, in this invention, A in general formula (AI) needs to be a 6-membered ring.

  A in the general formula (AI) may be a heterocyclic ring as long as it is a 6-membered ring. Moreover, since the same effect as a 6-membered ring is produced, A in the general formula (AI) may be a polycyclic fused ring composed of at least one 6-membered ring. Examples of such a polycyclic fused ring include the following. The polycyclic fused ring listed below may be a hetero fused ring in which the carbon on the ring is nitrogen, oxygen, sulfur or the like.

  In the case of a 6-membered aliphatic ring, it may be a saturated aliphatic ring such as a cyclohexyl group or an unsaturated aliphatic ring such as a cyclohexenyl group.

  In addition, the case where m in the general formula (AI) is 2 means that the A is connected by a single bond to be -AA-.

  Further, in the compound represented by the general formula (AI), L represents a linking group represented by the general formula (A-II). Although the function of the linking group L is not clear, it has a function of adjusting the viscosity of the liquid crystal composition to a suitable range when the compound represented by the general formula (AI) is used as the liquid crystal composition. I think that. When the liquid crystal is driven, if the viscosity of the liquid crystal composition is too high, the driving speed becomes slow and the power consumption increases. Further, when the linking group is chemically unstable, it becomes difficult to handle the production of liquid crystal. When the linking group L in the general formula (AI) is a linking group represented by the general formula (A-II), a liquid crystal compound having a suitable viscosity is obtained, and handling in production is facilitated.

Furthermore, in order to increase the polarization in the major axis direction in the compound represented by the general formula (AI), an electron-withdrawing group or an electron-donating group is used for R ² , or —CH═CH is used for the linking group L. - or -N = or with double bonds N-, an oxygen atom or a nitrogen atom having unpaired electron pair or placed in a linking group L _{(e.g., -COO -, - CH 2 -O} -, - N = N− etc.) is effective.

  In addition, in order to make the compound represented by the general formula (AI) into a dual-frequency driving liquid crystal compound, as shown below, in addition to polarization in the long axis direction, polarization is also performed in the short axis direction. Is preferred.

Here, in the compound represented by the general formula (AI), the carbonyl group (C═O) of the ester group adjacent to the 1,3-dioxane group promotes polarization in the major axis direction as described above. It was revealed that this also contributed to the polarization in the minor axis direction. Therefore, a compound having a 1,3-dioxane group and an ester group adjacent thereto is suitable as a dual frequency drive liquid crystal compound. Among them, when L in the general formula (AI) is an ester group (—COO—), the viscosity of the liquid crystal composition is in a particularly suitable range and the polarizability in the minor axis direction increases. Therefore, it becomes a more suitable dual frequency drive liquid crystal compound.
In addition, an electron-withdrawing group is used for X ^{1 to} X ⁶ , an electron-withdrawing group is used for the 6-membered ring represented by A, and an ester group (carbonyl group) that polarizes in the minor axis direction on the linking group L. Use is effective for polarization in the minor axis direction, and such a compound is also suitable as a dual frequency driving liquid crystal compound.

Below, the compound represented by general formula (AI) is demonstrated in detail.
The substituents represented by R ¹ , R ² , and X ^{1 to} X ⁶ in the general formula (AI) are substituents selected from the substituent group W below.

(Substituent group W)
When a halogen atom, an alkyl group (including a cycloalkyl group and a bicycloalkyl group), an alkenyl group (including a cycloalkenyl group and a bicycloalkenyl group), an alkynyl group, an aryl group, and a heterocyclic group (hereinafter referred to as “heterocyclic group”) ), Cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, amino group (including anilino group), acylamino group Alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl and arylsulfonylamino group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group, Sil group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl and heterocyclic azo group, imide group, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, phosphono group, silyl group, ureido The group is given as an example.

  More specifically, the substituent group W represents a halogen atom (for example, a fluorine atom or a chlorine atom), an alkyl group [a linear, branched or cyclic substituted or unsubstituted alkyl group. They are alkyl groups (preferably alkyl groups having 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, t-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl). A cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably having 5 to 30 carbon atoms). A substituted or unsubstituted bicycloalkyl group, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms, for example, bicyclo [1,2,2] heptan-2-yl, bicyclo [2,2,2] octane-3-yl). An alkyl group (for example, an alkyl group of an alkylthio group) in the substituent described below represents an alkyl group having such a concept, but further includes an alkenyl group and an alkynyl group. ], An alkenyl group [represents a linear, branched, cyclic substituted or unsubstituted alkenyl group. They include alkenyl groups (preferably substituted or unsubstituted alkenyl groups having 2 to 30 carbon atoms, such as vinyl, allyl, prenyl, geranyl, oleyl), cycloalkenyl groups (preferably substituted or unsubstituted 3 to 30 carbon atoms, or An unsubstituted cycloalkenyl group, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms (for example, 2-cyclopenten-1-yl, 2-cyclohexen-1-yl), Bicycloalkenyl group (a substituted or unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a bicycloalkene having one double bond. For example, bicyclo [2,2,1] hept-2-en-1-yl, bicycl [2,2,2] oct-2-en-4-yl). An alkynyl group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, such as ethynyl, propargyl, trimethylsilylethynyl group),

An aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms such as phenyl, p-tolyl, naphthyl, m-chlorophenyl, o-hexadecanoylaminophenyl), a heterocyclic group (preferably 5 or 6 A monovalent group obtained by removing one hydrogen atom from a substituted or unsubstituted aryl group or non-aromatic heterocyclic compound, more preferably a 5- or 6-membered aromatic having 3 to 30 carbon atoms For example, 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazolyl, and cationic heterocyclic rings such as 1-methyl-2-pyridinio and 1-methyl-2-quinolinio Group), a cyano group, a hydroxyl group, a nitro group, a carboxyl group, an alkoxy group (preferably a C 1-30 substituent or A substituted alkoxy group such as methoxy, ethoxy, isopropoxy, t-butoxy, n-octyloxy, 2-methoxyethoxy), an aryloxy group (preferably a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms) For example, phenoxy, 2-methylphenoxy, 4-t-butylphenoxy, 3-nitrophenoxy, 2-tetradecanoylaminophenoxy), a silyloxy group (preferably a silyloxy group having 3 to 20 carbon atoms, for example, trimethylsilyloxy , T-butyldimethylsilyloxy), a heterocyclic oxy group (preferably a substituted or unsubstituted heterocyclic oxy group having 2 to 30 carbon atoms, 1-phenyltetrazol-5-oxy, 2-tetrahydropyranyloxy), An acyloxy group (preferably formyloxy A substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms, such as formyloxy, acetyloxy, pivaloyloxy, stearoyloxy, benzoyloxy, p -Methoxyphenylcarbonyloxy), a carbamoyloxy group (preferably a substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms, such as N, N-dimethylcarbamoyloxy, N, N-diethylcarbamoyloxy, morpholinocarbonyloxy N, N-di-n-octylaminocarbonyloxy, Nn-octylcarbamoyloxy),

An amino group (preferably an amino group, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted anilino group having 6 to 30 carbon atoms, such as amino, methylamino, dimethylamino, anilino, N-methyl-anilino, diphenylamino), acylamino group (preferably formylamino group, substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms) Groups such as formylamino, acetylamino, pivaloylamino, lauroylamino, benzoylamino, 3,4,5-tri-n-octyloxyphenylcarbonylamino), alkoxycarbonylamino groups (preferably substituted with 2 to 30 carbon atoms or Unsubstituted alkoxycarbonyl Amino group, e.g., methoxycarbonylamino, ethoxycarbonylamino, t-butoxycarbonylamino, n- octadecyloxycarbonylamino amino, N- methylcyclohexyl methoxycarbonylamino)

An aryloxycarbonylamino group (preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms, such as phenoxycarbonylamino, p-chlorophenoxycarbonylamino, mn-octyloxyphenoxycarbonylamino), Alkyl and arylsulfonylamino groups (preferably substituted or unsubstituted alkylsulfonylamino having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonylamino having 6 to 30 carbon atoms, such as methylsulfonylamino, butylsulfonylamino, phenyl Sulfonylamino, 2,3,5-trichlorophenylsulfonylamino, p-methylphenylsulfonylamino), an alkylthio group (preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms). Group, such as methylthio, ethylthio, n-hexadecylthio), arylthio group (preferably substituted or unsubstituted arylthio having 6 to 30 carbon atoms, such as phenylthio, p-chlorophenylthio, m-methoxyphenylthio), heterocyclic thio group (Preferably a substituted or unsubstituted heterocyclic thio group having 2 to 30 carbon atoms, such as 2-benzothiazolylthio, 1-phenyltetrazol-5-ylthio), a sulfamoyl group (preferably a substituent having 0 to 30 carbon atoms) Or an unsubstituted sulfamoyl group such as N-ethylsulfamoyl, N- (3-dodecyloxypropyl) sulfamoyl, N, N-dimethylsulfamoyl, N-acetylsulfamoyl, N-benzoylsulfamoyl, N- (N′-phenylcarbamoyl) sulfur Moil),

A sulfo group, an alkyl and an arylsulfinyl group (preferably a substituted or unsubstituted alkylsulfinyl group having 1 to 30 carbon atoms, a substituted or unsubstituted arylsulfinyl group having 6 to 30 carbon atoms, such as methylsulfinyl, ethylsulfinyl, phenylsulfinyl; , P-methylphenylsulfinyl), alkyl and arylsulfonyl groups (preferably a substituted or unsubstituted alkylsulfonyl group having 1 to 30 carbon atoms, a substituted or unsubstituted arylsulfonyl group having 6 to 30 carbon atoms, such as methylsulfonyl, Ethylsulfonyl, phenylsulfonyl, p-methylphenylsulfonyl), acyl group (preferably formyl group, substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, substituted or unsubstituted group having 7 to 30 carbon atoms) A reel carbonyl group, a heterocyclic carbonyl group bonded to the carbonyl group with a substituted or unsubstituted carbon atom having 4 to 30 carbon atoms, such as acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, pn-octyl Oxyphenylcarbonyl, 2-pyridylcarbonyl, 2-furylcarbonyl), an aryloxycarbonyl group (preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms, such as phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, pt-butylphenoxycarbonyl), an alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, -Butoxycarbonyl, n-octadecyloxycarbonyl), a carbamoyl group (preferably a substituted or unsubstituted carbamoyl having 1 to 30 carbon atoms, such as carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N, N- Di-n-octylcarbamoyl, N- (methylsulfonyl) carbamoyl), aryl and heterocyclic azo groups (preferably substituted or unsubstituted arylazo groups having 6 to 30 carbon atoms, substituted or unsubstituted groups having 3 to 30 carbon atoms) A heterocyclic azo group such as phenylazo, p-chlorophenylazo, 5-ethylthio-1,3,4-thiadiazol-2-ylazo), an imide group (preferably N-succinimide, N-phthalimide),

A phosphino group (preferably a substituted or unsubstituted phosphino group having 2 to 30 carbon atoms, such as dimethylphosphino, diphenylphosphino, methylphenoxyphosphino), a phosphinyl group (preferably a substituted or unsubstituted phosphino group having 2 to 30 carbon atoms) An unsubstituted phosphinyl group such as phosphinyl, dioctyloxyphosphinyl, diethoxyphosphinyl), a phosphinyloxy group (preferably a substituted or unsubstituted phosphinyloxy group having 2 to 30 carbon atoms such as , Diphenoxyphosphinyloxy, dioctyloxyphosphinyloxy), a phosphinylamino group (preferably a substituted or unsubstituted phosphinylamino group having 2 to 30 carbon atoms, such as dimethoxyphosphinylamino, Dimethylaminophosphinylamino), phosphor A silyl group (preferably a substituted or unsubstituted silyl group having 3 to 30 carbon atoms, such as trimethylsilyl, t-butyldimethylsilyl, phenyldimethylsilyl), a ureido group (preferably a substituted or unsubstituted group having 0 to 30 carbon atoms). Represents a substituted ureido group, such as N, N-dimethylureido.

  Two Ws may be bonded to each other to form a ring. Examples of such a ring include an aryl group, a non-aromatic hydrocarbon ring, and a heterocyclic ring. These can be further combined to form a polycyclic fused ring. For example, benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyridine ring, pyrazine ring, pyrimidine Ring, pyridazine ring, indolizine ring, indole ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, quinolidine ring, quinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinoxazoline ring, isoquinoline ring, carbazole ring, phenanthridine Ring, acridine ring, phenanthroline ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, phenothiazine ring, phenazine ring

Next, a polycyclic fused ring composed of a 6-membered ring and a 6-membered ring represented by A in the general formula (AI) will be described.
The 6-membered ring represented by A and the polycyclic fused ring composed of the 6-membered ring are as described above, and more preferably a linking group shown below.

  The polycyclic fused ring composed of the 6-membered ring or at least one 6-membered ring may further have a substituent. Examples of the substituent include the substituent group W.

These 6-membered rings or polycyclic fused rings composed of at least one 6-membered ring have no aromatic ring having a substituent to control various physical properties such as transition temperature, Δε, viscosity, and Δn of the liquid crystal. Any of the substituted aromatic rings can be preferably used.
When the 6-membered ring represented by A or the polycyclic fused ring composed of at least one 6-membered ring has a substituent, examples of the substituent include the substituents listed in the substituent group W described above. it can. As the substituent of A, in order to facilitate polarization in the minor axis direction among the substituent group W, a halogen atom (particularly a fluorine atom), an alkoxy group, a perfluoroalkoxy group, a cyano group, a carbonyl group , A carboxyl group, a nitro group, and the like are preferable, and a fluorine atom, a perfluoroalkoxy group, and a cyano group are more preferable.

When used as a compound exhibiting liquid crystallinity, R ¹ in the general formula (AI) is preferably a hydrogen atom, a fluorine atom, a chlorine atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, A cyano group, a nitro group, a carboxyl group, an alkoxy group, an aryloxy group, and an ester group. Here, the alkyl group, alkenyl group, alkynyl group, and alkoxy group may be linear, branched, or cyclic. Further, the alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, alkoxy group, and aryloxy group may have a substituent or may be unsubstituted.

More preferably, R ¹ is an alkyl group (preferably an alkyl group having 1 to 30 carbon atoms, more preferably 1 to 15 carbon atoms, still more preferably 4 to 12 carbon atoms), an alkenyl group (preferably carbon atoms). An alkynyl group (preferably an alkynyl group having 1 to 30 carbon atoms, more preferably an alkynyl group having 1 to 15 carbon atoms), an alkoxy group. (Preferably an alkoxy group having 1 to 30 carbon atoms, more preferably an alkoxy group having 1 to 15 carbon atoms), an aryloxy group (preferably a phenyloxy group). When the alkyl group, alkenyl group, alkynyl group and alkoxy group represented by R ¹ are longer than the above range of the carbon number, the melting point becomes high or a preferable liquid crystal phase is not taken.

R ² in the general formula (AI) is preferably an aryl group, a heterocyclic group, an alkyl group (cycloalkyl group) in order for the compound represented by the general formula (AI) to exhibit liquid crystallinity. , A bicycloalkyl group), an alkenyl group (including a cycloalkenyl group), and an alkynyl group. These groups may have a substituent or may be unsubstituted, may be monocyclic, or may form a polycyclic fused ring.

In particular, when R ² is an aryl group, it is preferable that the bonding group L has a substituent at the para position. Further, when the substituent is an electron-withdrawing group, since the polarization in the major axis direction of the compound represented by the general formula (AI) increases, a liquid crystal compound having a large positive dielectric anisotropy is obtained. Is preferred.

When used as a compound exhibiting liquid crystallinity, X ^{1 to} X ⁶ in formula (AI) are preferably a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, or an alkyl group, more preferably a hydrogen atom, A fluorine atom, a chlorine atom, a cyano group, an alkyl group, and a trifluoromethyl group.

Furthermore, X ¹ is particularly preferably a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and X ^{2 to} X ⁶ are particularly preferably a hydrogen atom or an alkyl group.

  In general formula (AI), L represents a linking group represented by the following general formula (A-II).

Among the linking groups L represented by the general formula (A-II), —COO— is preferable. When the compound represented by formula (AI) having a —COO— linking group L is used in the liquid crystal composition, the viscosity becomes suitable for driving the liquid crystal. In the case where the bonding group L is —CF ₂ —O—, there is a problem that the production is difficult from the viewpoint of the stability of the compound.

The compound represented by the general formula (AI) of the present invention is a compound represented by the following general formula (A-III) when used as a compound exhibiting liquid crystallinity. It is preferable from the viewpoint of spreading. The general formula (A-III) is a case where X ^{2 to} X ⁶ in the general formula (AI) are all hydrogen atoms.

In the general formula (A-III), R ¹ , R ² , X ¹ , m, A, and L are R ¹ , R ² , X ¹ , m, and A described in the general formula (AI), respectively. , And L.

  Among the compounds represented by the general formula (AI), compounds represented by the following general formulas (BI) to (BV) are preferable. The general formula (BI) is a case where A in the general formula (AI) is a 1,4-cyclohexylene group, and the general formula (B-II) is the general formula (A). -I) is the case where A is a 1,4-phenylene group, and the general formula (B-III) is a group in which A in the general formula (AI) is a decahydronaphthalene-2,6-diyl group. In the general formula (B-IV), A in the general formula (AI) is a naphthalene-2,6-diyl group, and the general formula (BV) is the general formula (BV). This is the case where A in (AI) is a tetrahydronaphthalene-2,6-diyl group. The compounds represented by the general formulas (BI) to (BV) are preferable from the viewpoint of extending the liquid crystal temperature range.

In the compounds represented by the general formulas (BI) to (BV), R ¹ , R ² , X ¹ and L are R ¹ and R ² described in the general formula (AI), respectively. , X ¹ and L have the same meaning, R ³ has the same meaning as R ² , and n represents an integer of 0 to 2.

  Among the compounds represented by the general formula (AI), a compound represented by the following general formula (A-IV) is preferable from the viewpoint of increasing the dielectric anisotropy.

In the general formula (A-IV), R ¹ , X ¹ , A and L have the same meanings as R ¹ , X ¹ , A and L described in the general formula (AI), and R ⁴ is a substituted group. Represents a group, and B has the same meaning as A described in formula (AI). m represents 1 or 2, and p represents 1 or 2.
The substituent represented by R ⁴ is preferably each independently a fluorine atom, a chlorine atom, a cyano group, a nitro group, a perfluoroalkoxy group, an alkyl group, an alkenyl group, an alkynyl group, or an alkoxy group. More preferably, they are an atom, a chlorine atom, a cyano group, a perfluoroalkoxy group, an alkyl group, and an alkoxy group.

In B in the general formula (A-IV), the positional relationship between the linking group L and the substituent R ⁴ is in the para position, so that the liquid crystallinity and dielectric constant in the compound represented by the general formula (DI) From the viewpoint of

  Among the compounds represented by the general formula (AI), particularly preferred are compounds represented by the following general formulas (CI) to (CV), and further a dual frequency driving liquid crystal. In the case of a compound, among these, it is a compound represented by the following general formula (D-I) to general formula (D-V).

R < ¹ >, R < ³ >, R < ⁴ >, X < ¹ >, L, and B in the general formulas (CI) to (CV) and (D-I) to (DV) are respectively represented by the general formula (A- It is synonymous with R < ¹ >, R < ³ >, R < ⁴ >, X < ¹ >, L, and B demonstrated by I), (BI)-(BV), and (A-IV).

Specific examples of the compound represented by formula (AI) in the present invention are shown below, but the present invention is not limited thereto.

By using the compound having a specific structure of the present invention, a compound having a large dielectric anisotropy | Δε | can be obtained. The large dielectric anisotropy | Δε | is effective for high-speed response of a device using a liquid crystal composition because the threshold voltage is low, and is a physical property necessary for various liquid crystal display systems.
In addition, since the compound having a specific structure of the present invention exhibits dual-frequency drive characteristics, a device using the compound of the present invention can be driven for display or the like by a dual-frequency drive method.

  The compound represented by the general formula (AI) of the present invention can be synthesized by a condensation reaction of a 1,3-dioxane-2-carboxylic acid compound and an alcohol compound (including an aromatic alcohol such as phenol). In the condensation reaction, as shown in Scheme 1 below, it can be synthesized by using a condensing agent used for organic synthesis such as dicyclohexylcarbodiimide. Alternatively, a carboxylic acid can be reacted with a chlorinating agent such as thionyl chloride or phosphorus oxychloride to synthesize an acid chloride, and then a condensation reaction with an alcohol can be performed.

  At this time, as shown in the following scheme 2, the corresponding 1,3-dioxanoic acid compound is subjected to a dehydration condensation reaction between the corresponding 1,3-diol compound and ethyl glyoxylate in the presence of an acid catalyst, and subsequently with an alkali. It can be synthesized by hydrolysis of the ester. At this time, functional groups that are weak to acids and bases such as cyano groups and ester groups are decomposed during the synthesis. Therefore, when introducing these substituents, they should be introduced after the synthesis of the 1,3-dioxane compound. Is preferred.

  The 1,3-dioxane ring into which two groups are introduced has a cis form and a trans form. Among them, a trans form compound exhibits exclusively liquid crystallinity. Therefore, the synthesized 1,3-dioxane compound needs to be purified by column chromatography or recrystallization. When the number of carbon atoms of the substituent of the 1,3-dioxane ring is increased, purification by column chromatography becomes difficult. In such a case, a method of purification by recrystallization is preferable.

2. Composition In addition, the present invention provides a composition containing at least one compound represented by formula (AI).
Such a composition may contain a compound represented by formula (AI) alone or in combination of two or more thereof, and a known compound used for liquid crystals may be added as appropriate to form a liquid crystal composition (preferably for a guest host). (Liquid crystal composition). The ratio of the compound of this invention in a composition is not specifically limited, According to a desired physical characteristic, it can mix in arbitrary ratios.
When the composition of the present invention is used as a liquid crystal composition, the physical characteristics (optical characteristics and the like) of the liquid crystal composition may be appropriately adjusted using the liquid crystal to be mixed. In the composition of the present invention, a liquid crystal compound that can be used in combination is not limited, but a dual-frequency liquid crystal (nematic or smectic) is preferable.

3. Display Device The compound and composition of the present invention can be used in a display device such as a liquid crystal display. For example, the display device includes a pair of electrode substrates and a liquid crystal layer disposed between the pair of electrode substrates, and the liquid crystal layer includes a compound represented by the general formula (AI) of the present invention. Contains at least one.

As an electrode, what formed the electrode layer on the board | substrate which usually consists of glass or a plastics can be used. Examples of the plastic substrate include acrylic resin, polycarbonate resin, epoxy resin, PES, and PEN.
As the substrate, for example, those described in pages 218 to 231 of “Liquid Crystal Device Handbook” (Japan Society for the Promotion of Science 142nd edition, Nikkan Kogyo Shimbun, 1989) can be used. The electrode layer formed on the substrate is preferably a transparent electrode layer. For example, it can be formed from indium oxide, indium tin oxide (ITO), tin oxide, or the like. As the transparent electrode, for example, those described in pages 232 to 239 of “Liquid Crystal Device Handbook” (Japan Society for the Promotion of Science 142nd edition, Nikkan Kogyo Shimbun, 1989) can be used.
Since the display device of the present invention uses the compound represented by the general formula (AI) having a large dielectric anisotropy | Δε |, the threshold power is reduced and the power consumption can be suppressed. In addition, since the compound represented by the general formula (AI) exhibits dual-frequency drive characteristics, the display device of the present invention using this compound can be displayed by dual-frequency drive.

  The display device of the present invention can be produced, for example, by placing a pair of substrates facing each other at intervals of 1 to 50 μm via a spacer or the like and arranging the liquid crystal composition of the present invention in a space formed between the substrates. it can. As the spacer, for example, those described in pages 257 to 262 of “Liquid Crystal Device Handbook” (edited by Japan Society for the Promotion of Science 142nd Committee, Nikkan Kogyo Shimbun, 1989) can be used. The liquid crystal composition of the present invention can be disposed in a space between substrates by coating or printing on the substrates.

  The display device of the present invention can be driven by a simple matrix driving method or an active matrix driving method using a thin film transistor (TFT). The driving method is described in detail, for example, on pages 387 to 460 of “Liquid Crystal Device Handbook” (edited by the 142th Committee of the Japan Society for the Promotion of Science, Nikkan Kogyo Shimbun, 1989). Available as a method.

  In addition to the compound represented by the general formula (AI) of the present invention, the display device of the present invention can employ compounds and members generally used for display devices as appropriate.

4). Optical Element The compounds and compositions of the present invention can also be suitably used as an optical element described below.
Specifically, the optical element in the present invention includes a circularly polarized light-emitting film, an optical film, a retardation film, a ferroelectric film, an antiferroelectric film, a functional film such as a piezoelectric film, etc., and (circular) polarized light. Functions of light-emitting elements, laser oscillation elements by optical excitation or electric field excitation (based on the primary photonic crystal effect), LCD backlights, non-linear optical elements, electro-optical elements, pyroelectric elements, piezoelectric elements, light modulation elements, etc. This refers to a sexual element.

In the present invention, the optical element is, for example, 1) a method in which the compound (or composition) of the present invention is applied to a single support or a pair of supports (cells, etc.) and then crosslinked, or 2) It can be produced by a method of injecting the compound (or composition) of the invention as it is.
Since these optical elements use a compound represented by the general formula (AI) having a large dielectric anisotropy | Δε |, the threshold power is reduced and the power consumption can be suppressed. In addition, since the compound represented by the general formula (AI) exhibits dual frequency drive, the optical element of the present invention using this compound can be displayed by dual frequency drive.

  In the case of a phase difference plate, a transparent support is used as the support. Although there is no restriction | limiting in particular as this transparent support body, Glass, TAC, PET, PEN, COP, PMMA, PS, a polycarbonate, etc. can be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.

[Example 1]
<Synthesis of Exemplary Compound (1)>

(Synthesis of Compound 1a)
Into a 500 ml three-necked flask purged with nitrogen, 1.0 mol / l lithium aluminum hydride (100 ml (0.1 mol), manufactured by Aldrich) is placed, and the internal temperature is adjusted to 5 ° C. or lower with an ice bath. Diethyl normal butylmalonate (8.0 g (0.037 mol)) is dissolved in 100 ml of dehydrated THF and added dropwise over 30 minutes with a dropping funnel. After completion of the dropwise addition, the reaction solvent is refluxed by heating to an internal temperature of 65 ° C. in a hot water bath. After 4 hours, disappearance of the raw materials was confirmed by thin layer chromatography, and the temperature of the reaction solution was lowered to 30 ° C or lower. 10 ml of water is added to the reaction solution to decompose unreacted lithium aluminum hydride. A 1N aqueous hydrochloric acid solution is added until the pH is 2 or more, and the reaction solution is extracted three times with 50 ml of ethyl acetate. The obtained ethyl acetate solution is washed with saturated brine and an aqueous sodium bicarbonate solution and dried over magnesium sulfate. Magnesium sulfate is filtered off and the resulting solution is concentrated to obtain 5.0 g of a crude product. The component organism is purified by flash column chromatography (hexane / ethyl acetate = 2/1) to obtain 4.4 g (yield 90%) of compound 1a.

(Synthesis of Compound 1b)
An ethyl glyoxylate monomer is synthesized from ethyl glyoxylate (polymer type) (47% by mass toluene solution) manufactured by Tokyo Chemical Industry according to the purification method manual of Tokyo Chemical Industry. 25 g of 85% by mass phosphoric acid is added to 25 g of ethyl glyoxylate (polymer type) (47% by mass toluene solution), and vacuum distillation is performed at 80 to 81 ° C./20.4 kPa to obtain 10 g of ethyl glyoxylate monomer. It should be noted that the obtained monomer is highly reactive and readily used after polymerization because it can be easily polymerized. In addition, the polymerization reaction is an exothermic reaction, and the internal pressure of the container may increase due to gas generated when stored in a tightly sealed container, so be careful not to store it.

  A 50 ml eggplant flask was charged with compound 1a (2.0 g (15.1 mmol)), ethyl glyoxylate monomer (1.7 g (17 mmol)), AMBERLIST (200 mg, manufactured by ICN Biomedicals) and 10 ml of chloroform, and a Dean-Stark reflux tube and Install Jim Roth. The mixture is heated to reflux in an oil bath for 4 hours, and the reaction solution is cooled with water. The reaction solution is filtered, and the compound in the container is washed out with ethyl acetate. The resulting chloroform-ethyl acetate solution is concentrated. Purification by silica gel chromatography (eluent: hexane / ethyl acetate = 3/1) gives 2.9 g (yield 89%) of compound 1b.

(Synthesis of Compound 1c)
A 100 ml eggplant flask is charged with compound 1b (2.9 g (13.4 mmol)), potassium hydroxide (7.5 g (134 mmol)), methanol 30 ml, and 12 ml water. The reaction vessel is heated in an oil bath at 70 ° C. After 4 hours, disappearance of raw materials is confirmed by thin layer chromatography, and the reaction solution is cooled in an ice bath. 1N hydrochloric acid aqueous solution is added until the reaction solution reaches pH 1, and the reaction solution is extracted three times with 20 ml of ethyl acetate. The resulting ethyl acetate solution is dried over magnesium sulfate and the magnesium sulfate is filtered off. By concentrating the obtained ethyl acetate solution, 2.0 g (yield 80%) of compound 1c is obtained.

(Synthesis of Compound 1d)
In a 2.0-liter eggplant flask, 2-fluoro-4-hydroxybenzonitrile (40 g (0.29 mol), manufactured by Tokyo Chemical Industry), sodium hydroxide (233 g (5.8 mol)), and 800 ml of water are added. . The reaction vessel is heated in an oil bath at 120 ° C. to reflux the reaction solvent. After 4 hours, disappearance of the raw materials was confirmed by thin layer chromatography, and the reaction solution was cooled to 30 ° C. A 3N aqueous hydrochloric acid solution is added until the reaction solution reaches pH 1 or higher. The reaction solution is ice-cooled to obtain 36.4 g of a crude product. The crude product is suspended in hexane and collected by filtration to obtain 40.1 g (yield 80%) of Compound 1d.

(Synthesis of Compound 1e)
In a 300 ml three-necked flask, compound 1d (10 g (64 mmol)), triethylamine (26.8 ml (192 mmol) manufactured by Wako Pure Chemical Industries), and 100 ml of THF are added. While adjusting the internal temperature from 35 ° C. to 40 ° C. with a water bath, tert-butyltrimethylsilyl chloride (21 g (141 mmol), manufactured by Tokyo Chemical Industry) is added in three portions. Stir for 2 hours and cool the reaction solution with water. To the reaction solution are added 1N hydrochloric acid (100 ml) and ethyl acetate (100 ml), and the organic layer is separated with a separatory funnel. The obtained solution is put into a separating funnel, the organic layer is washed with 1N hydrochloric acid, and the obtained organic layer is dried over magnesium sulfate. Magnesium sulfate is filtered off and the resulting ethyl acetate solution is concentrated to give a liquid on oil. The obtained liquid is dissolved in 90 ml of THF, and 80 ml of 12% potassium carbonate solution is added dropwise. After completion of the dropwise addition, the mixture is diluted with 400 ml of ethyl acetate and neutralized with 100 ml of 1N hydrochloric acid. The organic layer is separated with a separatory funnel, and the obtained organic layer is dried over magnesium sulfate. Magnesium sulfate is filtered off, and the resulting ethyl acetate solution is concentrated to obtain 15.7 g of a crude product. Purification by silica gel chromatography (eluent: hexane / ethyl acetate = 3/1) gives 14.0 g of compound 1e (yield 81%).

(Synthesis of Compound If)
In a 300 ml three-necked flask, compound 1e (14.2 g (53 mmol)), p-fluorophenol (5.9 g (53 mmol) manufactured by Wako Pure Chemical Industries), 4-dimethylaminopyridine (1.28 g (10.5 mmol) Tokyo 100 ml of dichloromethane). The external temperature is adjusted to 40 ° C. with a water bath, and 50 ml of a dichloromethane solution of dicyclohexylcarbodiimide (13 g (63 mmol)) is added dropwise. Heat to reflux for 2 hours and cool the reaction solution with water. To the reaction solution is added 30 ml of 1N hydrochloric acid and 100 ml of hexane, followed by filtration. The obtained solution is put into a separating funnel, and the organic layer is separated. The organic layer is washed with saturated brine and aqueous sodium bicarbonate, and the resulting organic layer is dried over magnesium sulfate. Magnesium sulfate is filtered off, and the obtained ethyl acetate solution is concentrated to obtain 15.6 g of a crude product. The obtained crude product is purified by silica gel chromatography (eluent: hexane / ethyl acetate = 10/1) to obtain 12.7 g (yield 67%) of compound 1f.

(Synthesis of Compound 1g)
Compound 1f (12.7 g (35 mmol)) and 130 ml of THF are placed in a 300 ml three-necked flask. The internal temperature is adjusted to 10 ° C. with an ice bath, and 42 ml (42 mmol) of a 1 mol / l tetrabutylammonium fluoride THF solution is added dropwise. The mixture is stirred at room temperature for 30 minutes, and 200 ml of ethyl acetate and 50 ml of 1N hydrochloric acid are added dropwise to the reaction solution. The obtained solution is put into a separating funnel, and the organic layer is separated. The organic layer is washed with saturated brine and aqueous sodium bicarbonate, and the resulting organic layer is dried over magnesium sulfate. Magnesium sulfate is filtered off, and the resulting ethyl acetate solution is concentrated to obtain 8.1 g of a crude product. The obtained crude product is recrystallized from methanol / water solution to obtain 7.5 g (yield 86%) of compound 1g.

(Synthesis of Compound 1)
Compound 1c (500 mg (2.7 mmol)), compound 1 g (660 mg (2.7 mmol)), and dichloromethane 10 ml are placed in a 100 ml three-necked flask. The internal temperature is adjusted to 5 ° C. or lower with an ice bath, and 15 ml of a dichloromethane solution of dicyclohexylcarbodiimide (710 mg (3.4 mmol)) is added dropwise. Stir at the same temperature for 3 hours and at room temperature for 1 hour. Add 100 ml of hexane to the reaction solution and filter. The obtained solution is put into a separating funnel, and the organic layer is separated. The organic layer is washed with saturated brine and aqueous sodium bicarbonate, and the resulting organic layer is dried over magnesium sulfate. 950 mg of a crude product is obtained by filtering off magnesium sulfate and concentrating the resulting ethyl acetate solution. The obtained crude product is purified by silica gel chromatography (eluent: hexane / ethyl acetate = 10/1 to 4/1) to obtain 870 mg (yield 78%) of Compound 1.

<Synthesis of Exemplified Compound (29)>
Bromination of p-hydroxybenzyl alcohol (manufactured by Wako Pure Chemical Industries), esterification of 4- (4-trifluoromethoxy-phenoxymethyl) phenol synthesized by reaction of this with p-trifluoromethoxyphenol and compound 1c Synthesized by reaction.

(Dielectric anisotropy Δε)
The dielectric anisotropy Δε is calculated by an extrapolation method using liquid crystal ZLI-1132 manufactured by Merck. The calculated dielectric anisotropy Δε is shown in Table 1 below. The structures of compounds 1 and 2 used for comparison are shown below.

  As shown in Table 1, it can be seen that the compound of the present invention has a large value of dielectric anisotropy at a low frequency and a high frequency and is suitable as a two-frequency driving liquid crystal.

[Example 2]
<Synthesis of Exemplary Compound (12)>
Below, the synthetic scheme of exemplary compound (12) is shown.

In a 1.0 liter stainless steel autoclave, p-hydroxybenzoic acid (100 g (0.72 mol), manufactured by Tokyo Chemical Industry), 5% Ru / C (35 g (0.017 mol), manufactured by Tokyo Chemical Industry), potassium hydroxide ( 91 g (1.4 mol)) and 500 ml of water. The inside of the autoclave is purged with nitrogen three times and replaced with hydrogen three times. As the hydrogen pressure decreases as the reaction proceeds, hydrogen is added as appropriate. When the decrease in hydrogen pressure is no longer observed, the hydrogen pressure is released and replaced with nitrogen. The reaction solution is filtered through Celite, and the resulting aqueous solution is neutralized with 5N hydrochloric acid to bring the pH to 1 or less. Extract three times with ethyl acetate and dry the resulting organic layer over magnesium sulfate. Magnesium sulfate is filtered off and the resulting ethyl acetate solution is concentrated to yield 78 g of crude product. This composition organism is suspended in hexane and collected by filtration to obtain 40 g (yield: 39%) of a mixture (2a) having a cis / trans ratio of 1: 7.
The cyclohexanol compound (2a) synthesized as described above was subjected to an esterification reaction with a dioxane carboxylic acid derivative synthesized in the same manner as in Example 1. The compound 12 can be synthesized by deprotection by hydrogenation and esterification with phenols.

Claims (9)

The compound represented by the following general formula (AI).

[In General Formula (AI), R ¹ , R ² , and X ^{1 to} X ⁶ each independently represent a hydrogen atom or a substituent, and L is represented by the following General Formula (A-II) It represents any one linking group, and A represents a 6-membered ring or a polycyclic fused ring composed of at least one 6-membered ring. M represents 1 or 2]

  The compound according to claim 1, wherein the linking group represented by L is -COO-. X < ² > -X < ⁶ > in the said general formula (AI) is a hydrogen atom, The compound of Claim 1 or Claim 2 characterized by the above-mentioned.   When A in the general formula (AI) is a 6-membered ring, it is a 6-membered ring having a bonding position at the 1,4-position. Compound. The compound represented by said general formula (AI) is a compound represented by the following general formula (BI)-(BV), The compound of Claim 4 characterized by the above-mentioned.

[In the general formulas (BI) to (BV), R ¹ , R ² , R ³ and X ¹ each independently represents a hydrogen atom or a substituent, and L represents the general formula (A-II). ) Represents any one linking group represented by: ]   When A in the general formula (AI) is a bicyclo group composed of a 6-membered ring, it is a bicyclo group having a bonding position at positions 3 and 8; 2. The compound according to item 1.   The composition which contains at least 1 sort (s) of the compound of any one of Claims 1-6.   A retardation plate having a transparent support and at least one optically anisotropic layer containing the composition according to claim 7 on the transparent support.   A display device comprising: a pair of electrode substrates; and a liquid crystal layer containing the composition according to claim 7 between the pair of electrode substrates.