GB2184743A

GB2184743A - Electroconductive bis-pyridone methine dye salts

Info

Publication number: GB2184743A
Application number: GB08629352A
Authority: GB
Inventors: Douglas James Edwards; Stephen Roderick Postle; Martin Christopher Grossel; Terence Charles Webb
Original assignee: Ciba Geigy AG
Current assignee: Novartis AG
Priority date: 1985-12-11
Filing date: 1986-12-03
Publication date: 1987-07-01
Also published as: GB8629352D0; GB8530456D0

Abstract

Novel dye salts (I) are useful as semiconductors and as bleachable dyes. <IMAGE> wherein T<1>-T<4> and Z<1>-Z<2> are each H or specified substituents, and D<+> is selected from cations (II)-(V):- <IMAGE> wherein V<1>-V<6> are each S, Se, Te; X is S or Se; and the remaining symbols are as defined in the specification.

Description

SPECIFICATION Organic electroconductive compounds THIS INVENTION relates to organic dyes which are of use as semiconductors.

There are a large number of uses for semiconducting dyes for example in rectifiers, in microwave generation, in thermoelectric devices, as gas detectors, as electrets, as infra-red light detectors and as pressure indicators. Organic dyes which are semi-conducting and readily bieachable find use in semi-conductor layers wherein it is required that the later be rendered substantially colourless after it has been used. Often inorganic semi-conductors are difficult to coat. A number of organic polymeric compounds are known which exhibit semi-conductor properties, but these compounds are highlycoloured and this colourcannot easily be reduced or destroyed.

According to the present invention there are provided compounds of the general formula:

wherein T1 and T3 each represent a hydrogen atom or a hydroxy, -CN,-COOR1,-CONB1R2 or-COR1 group oran optionally substituted alkyl, arlykl, cycloalkyl aryl or heterocyclicradical;T2 and T4each represent a hydrogen atom or a -ON, -COOR3, --CONR3R4 or-COR3 group or an optionally substituted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic ring and R1, R2, R3 and R4 each independently represent a hydrogen atom or an optionally substituted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical or R1 and R2 together form with thenitrogen atom N a 5- or6-membered nitrogen containing heterocyclic radical or R3 and R4 together form with the nitrogen atom N a 5- or 6-membered nitrogen containing heterocyclic radical.Z' and Z2 each represent a hydrogen atom or an optionally su bsti- tuted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical, an optionally substituted amino ring or a grou p -(CH2jx-R2 where R2 is a group which contains an amino nitrogen and xis 1 to 6, and D+ isa cation selected from cations of the general formula Il:-

where Va, V2, V3 and V4 are each selectedfrom S, Se or Te and W1 toW4 are each hydrogen, ethyl or methyl or W1 and W2 and/orW3 and W4 can together form a carbocylic ring, cations of general formula Ill::-

where V5 and V6 are each selected from S, Se or Te and W5 to W12 are each hydrogen, ethyl or methyl and any one of W5 and W6, W7 and W8, W9 and W10 and W11 and W12 can together form a carbocyclic ring, cations ofthe general formula IV::

wherein Tis S or Se and R4 and R6 are each hydrogen, or R4 is-COR1 and R6 is-COR1 or hydrogen wherein R1 is alkoxy with 1 to 12 carbon actoms, cycloalkoxy with 5to 16 carbon atoms, hydroxyalkoxywith 2to 12 carbon atoms, arlyoxy with 6 to 16 carbon atoms, aralkoxy with 7 to 12 carbon atoms, -OH, -NH2, -01,-Br or-NR2R3 wherein R2 is alkyl with 1 to 12 carbon atoms, cycloalkyl with 5 to 16 carbon atoms, hydroxyal kyl with 2 to 12 carbon atoms, aryl with 6 to 16 carbon atoms or aralkyl with 7 to 16 carbon atoms and R3 is hydrogen or has one of the values of R2 as just set forth, or R4 and R6form together an anhydride group::-

ora cyclic imidegroup:

where Raisdefined above orwhen Xis Se R4 may be F and R6 hydrogen, or cations ofthe formula V:

where R7, R8 and R9 are each alkyl or aryl.

Preferablyin formulal T1 =T34T2 = T4 and zl = Z2 Preferably T1 and T3 are either methyl or ethyl.

Mostpreferably T2 and T4 are either-CN or -CON H2.

Most preferably2' and Z2 are either an alkyl group having 1 to 6carbon atoms or phenyl.

Preferably in formula ll V1 = v2 and V3 = V4. Most preferably in formula Il V1 = V2 = V3 = V4.

Preferably in formula Ill V5 = V6.

For ease of preparation it is preferred thatthe cations of formulae II and Ill are symmetrical compounds.

Particularly preferred cations are cations 1 to 6 is as setforth below: Cation 1 N-methyl phenazinium

Cation 2 tetrathiafulvalinium

Cation 3tetraselenafulvalinium

Cation 4 hexamethylenetetraselenafulvalinium

Cation 5 tetramethyl tetrathiafulvalinium

and Cation 64,4-bithiopyranium

According to another feature of the present invention there is provided the use ofthecompounds of formula las organic semi-conductors-.

It is thought that some of those compounds which act as organic semi-conductors do so because the anion portion ofthe molecules are planar molecules which are packed face-to-face like a packof playing cards with separated stacks of cations ratherthan a mixed stackwith alternating donors and acceptors. In this case it isthoughtthatthe bispyridone anions are thin planar molecules which are able to pack face-to face.

Notonly are the compounds offormula I semi conductors, they are also bleachable dyes. Thus the α, ss-unsaturated carbonyl centres can be bleached by nucleophic ions such as --S032-, CN-, OH-, S2-- SH- and compounds such as RNH21 and NH3. This renders the compounds offormula I useful for the laying down of integrated circuits (I.C's) wherein the circuit ing can be etched onto a thin deposited layer of the semi-conductor offormula I by etching with a mild aqueous-based bleachant, for example aqueous sodium sulphite. This compares with the strong acids which are required to etch silicon based I.C.'s.

Compounds offormula I may be prepared electrochemicallyfrom compounds offormula I, but wherein D+ isa different cation,forexample Bu4N+.

The schematic formation of a compound offormula I where D+ is tetrathiafulvalinium (orTTF) is shown in the Figure I which accompanies this specification.

Forthe preparation of each compound offormula I a narrow potential range only is availableto ensure that the compound is obtained in high purity and yield.

The following Examples will serveto illustratethe invention: Example 1 Preparation of Compouynd I oftheformula VI:

Referring tothe accompanying figure 1 equimolecular parts of the bispyridone having the Bu4N+cation (5.0 x 10-4 mol) and TTF (5.0 x mol) dissolved in a mixture ofacetonitrile and tetrabutylammoniu m perchlorate were electrolysed in a cell having platinum electrodes art a current of 2mAfor4 hours.

Compound offormula VI as setforth above crystallised on the anode. it is a black crystaline solid having a melting pointof230'C. (decomp).

FoundC, 53.6%, H. 4.0%, N.9.4% and S, 21.7%.

Calculated for C27H23Q4N4S4 C,54.0%, H.3.9%, N, 9.4%, S,21.4%.

Spectral details ofthe compound u.v./visible, Amax (EtOH)597, (smax 4.72 x 104) 552 nm (Sh, 1.16 x 104 mol-1 dm3cm-1) The room temperature d.c. conductivity ofthe compacted powderwas8.0 x 10-4Q- cm~1.

The electrochemistry oftheformation of compound I was investigated by cyclic voltametry to determine the optimum conditions for its preparation. An electrocrystallisation potential of =0.7v versus the Standard Calomel Electrode is required.

However if the potential is raised to 1.1Vversusthe Standard Calomel ElectrodetheTTF + radical cation isfurtheroxidisedtoTTF2+.

Claims

1. A compound of the general formula:-

wherein T' and T3 each represent a hydrogen atom or a hydroxy,-CH,-COOR1,-CONR1R2or-COR1 group or an optionally substituted alkyl, arylkyl, cycloalkyl aryl or heterocyclic radical; T2 and T4 each represent a hydrogen atom ora-CN,-COOR3, -CONR3R4 or-COR3 group or an optionally substituted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic ring and R1 R2, R3 and R4 each independently represent a hydrogen atom or an optionallysubsti- tuted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical or Rt and R2 together form with the nitrogen atom N a 5- or6-membered nitrogen containing heterocyclic radical or R3 and R4togetherform with the nitrogen atom N a5-or 6-membered nitrogen containing heterocyclic radical.Z' and Z2 each represent a hydrogen atom oran optionally substituted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical, an optionally substituted amino ring ora grnup-(CH2)-R2 wherein R2 is a group which contains an amino nitrogen and xis 1 to 6, and D+ is a cation selected from cations ofthe general formula Il:-

where V', V2, V3 and V4 are each selected from S, Se or Te and W1 toW4 are each hydrogen, ethyl or methyl or W1 and W2 and/or W3 and W4 cantogether form a carbocylic ring, cations of general formula Ill::-

where V5 and V8 are each selected from S, Se orTe and W5 toW12 are each hydrogen, ethyl or methyl and any one of W5 and W6, W7 and W8, Wg and W,O and W11 and W12 can together form a carbocyclic ring, cations of the general formula IV:cations ofthe general formula IV::

wherein Xis S or Se and R4 and R6 are each hydrogen, orR4is-COR1 and R6is-CO R1 or hydrogen wherein R1 is alkoxy with 1 to 12 carbon atoms, cycloalkoxywith Sto 16carbon atoms, hydroxyalkoxy with 2 to 12 carbon atoms, arlyoxy with 6 to 16 carbon atoms, aralkoxy with 7 to 12 carbon atoms, -OH, NH2,-Cl,-Bror-NR2R3wherein R2is alkyl with 1 to 12 carbon atoms, cycloalkyi with 5 to 16 carbon atoms, hydroxyalkyl with 2 to 12 carbon atoms, aryl with 6 to 16 carbon atoms or aralkyl with 7 to 16 carbon atoms and R3 is hydrogen or has one of thevaluesofR2asjustsetforth,orR4and R6form together an anhydride group::

or a cyclic imide group:

where R3 is as defined above orwhen Xis Se R4 may be F and R6 hydrogen, ora cation oftheformula V:

where R7, R8 and Rg are each alkyl or aryl.

2. A compound according to claim 1 wherein formula I Ta = T3, T2 = T4 and z1 =z2.

3. A compound according to either claim 1 or claim 2 wherein T' and T3 are either methyl or ethyl.

4. A compound according to any one of claims 1 to 3 wherein T2 and T4 are either or-OONH2.

5. A compound according to any one of claims 1 to 4 wherein Z1 and Z2 are either an alkyl group having 1 to 6 carbon atoms or phenyl.

6. A compound according to any one of claims 1 to Swhere in formula Il V1 = V2 and V3 = V4.

7. A compound according to claim 6 wherein V1 = V3.

8. A compound accordingto any one of claims 1 to 7 where in formula lil V5 = V6.

9. Acompoundaccordingto any one of claims 1 to 5 wherein D is one ofthe cations 1 to 6 as hereinbefore set forth.

10. The use of a compound as claimed in any one of claims 1 to 9 as an organic semi-conductor.

11. The use of a compound as claimed in any one of claims 1 to 9to prepare an integrated circuit.