Process for preparing linear organic oligomers
View Patent ↗The present invention relates to a process for preparing compounds of the formula (I), where n is an integer from 2 to 5, R 1 is H or a C 1 -C 20 -alkyl group which may be interrupted by one or more O or S atoms, silylene, phosphonoyl or phosphoryl groups and Ar is substituted or unsubstituted 1,4-phenylene, 2,7-fluorene or 2,5-thiophene, with Ar being able to be identical or different, semiconductive layers comprising these compounds and their use in semiconductor technology.
1. Process for preparing compounds of the formula (I),
where
n is an integer from 2 to 5,
R 1 is H or a C 1 -C 20 -alkyl group optionally interrupted by one or more O or S atoms, silylene, phosphonoyl or phosphoryl groups and
Ar is substituted or unsubstituted 1,4-phenylene, 2,7-fluorene or 2,5-thiophene, with Ar being able to be identical or different,
comprising completely dissolving compounds of the formula (II),
where n, R 1 and Ar are as defined for the formula (I),
in an organic solvent or solvent mixture at a temperature of from −100° C. to +20° C. and coupling with one another at temperatures of from −100° C. to +20° C. with the aid of one or more copper(II) compound(s).
2. Process for preparing compounds of the formula (I-a),
where
n is an integer from 2 to 4,
R 1 is H or a C 1 -C 20 -alkyl group optionally interrupted by one or more O or S atoms, silylene, phosphonoyl or phosphoryl groups and
R 2 , R 3 are each, independently of one another, H or a substituted or unsubstituted C 1 -C 20 -alkyl group, a substituted or unsubstituted C 1 -C 20 -alkoxy group or together form a substituted or unsubstituted C 1 -C 6 -dioxyalkylene group,
comprising completely dissolving compounds of the formula (II-a)
where n, R 1 , R 2 and R 3 are as defined for the formula (I-a),
in an organic solvent or solvent mixture at a temperature of from −100° C. to +20° C. and coupling with one another at temperatures of from −100° C. to +20° C. with the aid of one or more copper(II) compound(s).
3. Process according to claim 1 , characterized in that n is 2 or 3.
4. Process according to claim 1 , characterized in that R 1 is a C 1 -C 12 -alkyl group.
5. Process according to claim 2 , characterized in that R 2 and R 3 are each, independently of one another, H or a C 1 -C 6 -alkyl group.
6. Process according to claim 2 , characterized in that R 2 and R 3 are each H.
7. Process according to claim 1 , characterized in that alkanes, aromatics or compounds containing ether groups or mixtures of two or more of these compounds are used as solvent.
8. Process according to claim 1 , characterized in that tetrahydrofuran or a mixture of tetrahydrofuran with alkanes is used as solvent.
9. Process according to claim 1 , characterized in that the compounds of the formula (II) are prepared by reacting compounds of the formula (III),
where n, R 1 and Ar are as defined in claim 1 , and
X is H, Cl, Br or I,
with an organolithium compound at a temperature of from −100° C. to +20° C. in an organic solvent,
where the resulting reaction mixture is stirred further, optionally at or after heating to a temperature of from −20° C. to +40° C., and is subsequently cooled back down to a temperature of from −100° C. to +20° C. and
the copper(II) compound is added without further work-up.
10. Process according to claim 9 , characterized in that the compounds of the formula (III) are compounds of the formula (III-a),
wherein
n is an integer from 2 to 5,
R 1 is H or a C 1 -C 20 -alkyl group optionally interrupted by one or more O or S atoms, silylene, phosphonoyl or phosphoryl groups and
R 2 and R 3 are each, independently of one another, H or a substituted or unsubstituted C 1 -C 20 -alkyl group, a substituted or unsubstituted C 1 -C 20 -alkoxy group or together form a substituted or unsubstituted C 1 -C 6 -dioxyalkylene group and
X is H, Cl, Br or I.
11. Process according to claim 9 , characterized in that the organolithium compound is a lithium amide, or a complexed or uncomplexed alkyllithium compound.
12. Process according to claim 1 , characterized in that the copper(II) compound is a copper(II) halide, a copper(II) salt of a carboxylic acid or sulphonic acid, or a copper(I) alkoxide.
13. Process according to claim 1 , characterized in that the reaction mixture is stirred further at temperatures of from −80° C. to +40° C. to complete the coupling reaction.