PL200555B1 - New metallic complexes of enamino ketone derivatives of 2, 3-diamino-2-dinitrile butene - Google Patents

Abstract

1. New metallic enaminoketone complexes 2,3-diamino-2-butenedinitrile derivatives of general formula I, wherein R1 and R4 are the same and represent hydrogen or C1- -C10alkyl, straight or branched chain, R2 and R3 are the same and represent a group Straight chain or branched C1-C12alkyl or an optionally substituted phenyl group 1 to 4 the same or different substituents selected from the groups C1- -C14alkoxy and C1-C14alkyl and M is Ni, Co, Cu or a VO group.

Description

The subject of the invention is new metallic complexes of enaminoketone derivatives of 2,3-diamino-2-butenedinitrile having the properties of a discotic liquid crystal material. This material can be used in electronic devices, especially in displays.

Most of the commercially used liquid crystal compounds have elongated (rod-shaped) molecules, while discotic liquid crystal compounds have rather limited applications.

Discotic liquid crystal materials used in electronic devices, e.g. displays, are presented in various publications. Known materials include polycyclic compounds, mainly triphenylenes (US Patent No. 6,380,996, International Application WO 02/054141), azacorone derivatives (US Patent No. 6,380,996, Japanese Patent No. JP2000327667), phenylacetylene derivatives (US Patent No. 6,380,996) , benzene or cyclohexane derivatives (EP 1207408).

The enaminoketone metal complexes with bidentate ligands known from the Polish patent specification No. 164001 show the presence of liquid crystalline calamitic phases - they are not discotic compounds.

The novel enaminoketone derivatives of the invention have been found to be more stable than the bidentate ligand complexes described in cited patent No. 164001, and the presence of strongly polar cyano groups facilitates the orientation of the molecules by the electric field.

The invention relates to compounds of general formula 1 wherein R1 and R4 are the same and represent hydrogen or C1-C1 ₀ alkyl straight or branched chain, _R2 and R3 are the same and represent a C1-C1 ₂ alkyl, straight chain or branched, or a phenyl group optionally substituted with 1 to 4 with the same or different substituents selected from C1-C14 alkoxy and C1-C14alkyl groups, and M is Ni, Co, Cu or a VO group.

The term alkyl includes straight and branched radicals and may be chiral. When the substituent is a chiral group, the compound of formula I can be obtained as pure optical isomers, mixtures of enantiomers predominantly of one of them, or as a racemate. Preferred groups are C8-C 1 -C ₂ alkyl or C1-C8 alkoxy _two.

Preferred compounds of formula 1 include those in which R 1 and R 4 are hydrogen, M is Ni, and R ₂ and R 3 are phenyl substituted with 1 to 3 C 8 -C _1-2 alkoxy groups, especially phenyl group substituted with 3 C ₀ alkoxy groups.

Exemplary complexes according to the invention are compounds of formula I in which:

R1 and R4 are hydrogen, _R2 and R3 are -C6H4-OC8H17, and M is Ni;

R1 and R4 -C6H13, _R2 and R3 are -C7H15 and M represents Cu or Ni;

R1 and R4 are hydrogen, _R2 and R3 are 2,3,4-C6H4 (OC1 _{0 2} 1 H) 3, and M is Ni;

A process for preparing complexes lies in the fact that 2,3-diamino-2-butenodinitryl is reacted with the enol form of formyloketonu of Formula 2: HO-CH = CR _r CO-R ₂ wherein R 1 and R ₂ are as defined above then the resulting intermediate is reacted with a salt or a transition metal complex. The reaction of 2,3-diamino-2-butenedinitrile with formyl ketone generally takes place at the reflux temperature of the reaction mixture, preferably in organic solvents such as, for example, alcohols. The metal complexes are obtained by reaction with a salt or complex of a transition metal such as Ni, Co, Cu or V in the form of a VO group. Preferred transition metal salts are fatty acid salts such as acetates or formates. If salts of stronger acids are used, the reaction mixture must be neutralized. The reaction is usually carried out in an alcoholic or hydroalcoholic medium at the boiling point of the reaction mixture. The starting materials used are known compounds or can be obtained from known compounds. Formyl ketone derivatives are obtained from the corresponding ketones by reaction with an ester of formic acid in the presence of molecular sodium. The complexes of formula 1, due to their liquid crystal properties and intense color, are useful mainly as components of mixtures for liquid crystal displays.

The following examples illustrate the invention in more detail. The following designations were adopted in the examples: Cr - crystal phase, Dh - hexagonal disco phase, Ph-phenyl.

P r z x l a d I.

A mixture of 0.750 g of 4-octyloxyacetophenone with 0.4 g of ethyl formate was added dropwise with stirring to 0.1 g of molecular sodium in 15 cm ^{3 of anhydrous ether and left overnight.} Ether removed under

Under reduced pressure, the remaining sodium formylketone was dissolved in 20 ml of methanol, 0.11 g of 2,3-diamino-2-butenedinitrile in 10 ml of methanol was added and neutralized with a solution of acetic acid in methanol. The resulting mixture was heated to reflux for 5 minutes, 0.25 g of nickel acetate in 5 ml of methanol was added and heated to reflux for a further 5 minutes. After cooling, the resulting precipitate was filtered off and subjected to thin-layer chromatography (silica gel, methylene chloride). 70 mg (yield about 10%) of the compound of formula I was obtained, in which R1 and R4 = H, R2 and R3 = p-Ph-OC ₈ H17, M = Ni in the form of red crystals.

Melting point 186 ° C.

¹ H NMR (CDCl 3): δ = 0.90 (m, 6H); 1.22-1.86 (m, 24H); 4.04 (t, J = 6.6 Hz, 4H); 6.48 (d, J = 7.1 Hz, 2H); 6.96 (d, J = 9.3 Hz, 4H); 7.35 (d, J = 7.1 Hz, 2H); 7.95 (d, J = 9.3 Hz, 4H).

P r x l a d II - III.

The reaction was carried out analogously to example 1, except that 8-pentadecanone (0.7 g) was used instead of 4-octyloxyacetophenone. Chromatography was not used either, only crystallization from hexane. The yield was 0.4 g (about 60% yield) of the compound of formula I, where R1 and R4 = n-C6H13, R2 and R3 = n-C7H15, M = Ni in the form of red crystals.

Melting point 112 ° C.

¹ HNMR (CDCls): δ = 0.90 (m, 12H); 1.22-1.72 (m, 18H); 2.38 (t, J = 7.3 Hz, 6H); 2.59 (t, J = 7.3 Hz, 6H); 7.15 (s, 2H).

An analogous compound where M = Cu was obtained in similar yield by using copper acetate instead of nickel acetate. Red crystals with a melting point of 95 ° C.

P r x l a d IV.

The reactions were carried out in the same way as in Example 1, except that 2,3,4-tridecyloxyacetophenone (1.7 g) was used instead of 4-octyloxyacetophenone. The product was purified by thin layer chromatography (silica gel, methylene chloride). Afforded 92 mg (approximate yield 9%) of the compound of formula 1 wherein R1 and R4 = H, R2 and R3 = 2,3,4-Ph (OC1 ₀ H21) 3, M = Ni as a red substance.

Phase transitions (in ° C) Cr 44 Dh 75 I.

¹ HNMR (CDCls): δ = 0.84-0.91 (m, 18H); 1.20-1.87 (m, 48H); 3.94-4.03 (m, 16H); 6.70 (d, J = 9.0 Hz, 2H); 6.89 (d, J = 7.0 Hz, 2H); 7.35 (d, J = 7.0 Hz, 2H); 7.55 (d, J = 9.0 Hz, 2H).

Claims (3)

1. New metaliccne komplekky enaminoketonowyyh ppohoonyyh 2,3-diamino-2-butenodinitrylu of formula 1 wherein R1 and R4 are the same and represent hydrogen or C1-C1 ₀ alkyl straight or branched chain, R2 and R3 are alone and represent a straight or branched C1-C12alkyl group or a phenyl group optionally substituted with 1 to 4 with the same or different substituents selected from C1-C14alkoxy and C1-C14alkyl groups, and M is Ni, Co, Cu or VO. 2. Komelenky weeługzzstry. k, wherein R ₁ 1 R _{4 is} vodr, R ₂ and R _{3 are} rppfetyl substituted with 1 to 3 C ₈ -C 12 alkoxy groups, and M is Ni. 3. Komelenk weeług kzstry. 2, in ΜΟ ^ πρ R ₂ and R ₃ denote 2enol crrPp ppd with 2 C ₀ alkoxy caps.