Method for controlling the molecular weight during poly(arylene vinylene) synthesis, and polymers produced therewith
View Patent ↗The present invention relates to a process in which addition of certain bis(methyl)aryl compounds which have a further substituent other than hydrogen and on which at least one of the two methyl groups bears a leaving group, the molecular weight in the synthesis of poly(arylenevinylenes) is controlled reproducibly and can be deduced by the GILCH polymerization or by the sulfinyl precursor route, and to the polymers obtainable by means of the process according to the invention.
1. A process for preparing poly(arylenevinylenes) from bis(halomethyl)arylene of the formula (XXVI),
which comprises base-induced dehydrohalogenation, wherein the reaction is carried out in the presence of between 2 and 40 mol% of one or more compounds of the formula (I):
where the symbols are defined as follows:
Aryl is the same or different at each instance and is a bivalent aromatic or heteroaromatic ring system which has from 2 to 40 carbon atoms and is substituted by R 1 radicals, or an R 1 -substituted or unsubstituted stilbenylene unit; the two substituents CHXR and CHYR are arranged in such a way that there is an even number of aromatic atoms between them; the aryl and heteroaryl systems may also be part of a larger fused aromatic ring system; the possible substituents R 1 may potentially be situated at any free position;
R is the same or different at each instance and is an alkyl chain which has from 4 to 40 carbon atoms, and may also be substituted by one or more R 1 radicals or be unsubstituted, in which one or more nonadjacent carbon atoms may also be replaced by —CR 2 ═CR 2 —, —C≡C—, —NR 2 —, —O—, —S—, —CO—, —CO—O—, —CONR 2 —, —O—CO—O—, and one or more hydrogen atoms may also be replaced by fluorine, an aromatic or heteroaromatic ring system which has from 2 to 40 carbon atoms and may be substituted by R 1 or be unsubstituted, an R 1 -substituted or unsubstituted stilbenyl or tolanyl unit, —Si(R 2 ) 3 , —N(R 2 ) 2 , —OR 2 or a combination of these systems; the aryl and heteroaryl systems may also be part of a larger fused aromatic ring system; the possible substituents may potentially be situated at any free position;
X is the same or different at each instance and is Cl, Br, I, trifluoromethanesulfonate or arylsulfonate;
Y is the same or different at each instance and is Cl, Br, I, trifluoromethanesulfonate, arylsulfonate or R 1 ;
Z is the same or different at each instance and is Cl, Br, I, trifluoromethanesulfonate, arylsulfonate or —S(O)R 2 ;
R 1 is the same or different at each instance and is a straight-chain, branched or cyclic alkyl chain having from 1 to 40 carbon atoms, in which one or more nonadjacent carbon atoms may also be replaced by —CR 2 ═CR 2 —, —C≡C—, —NR 2 —, —O—, —S—, —CO—, —CO—O—, —CONR 2 —, —O—CO—O—, and one or more hydrogen atoms may be replaced by fluorine, an aromatic or heteroaromatic ring system which has from 2 to 40 carbon atoms and may also be substituted by one or more nonaromatic R 1 radicals, a substituted or unsubstituted vinyl group or Cl, F, CN, N(R 2 ) 2 , B(R 2 ) 2 ; the aryl and heteroaryl systems may also be part of a larger fused aromatic ring system; the possible substituents may potentially be situated at any free position; two or more R 1 radicals together may also form a ring system;
R 2 is the same or different at each instance and is H, a straight-chain, branched or cyclic alkyl chain having 1 to 22 carbon atoms, in which one or more nonadjacent carbon atoms may also be replaced by —O—, —S—, —CO—O—, —O—CO—O—, and one or more hydrogen atoms may also be replaced by fluorine, an aryl or heteroaryl system which has from 2 to 40 carbon atoms and may also be substituted by one or more nonaromatic R 1 .
2. The process as claimed in claim 1 , wherein the halogen atoms in the bis(halomethyl)arylene monomers are the same or different and are each Cl, Br or I.
3. The process as claimed in claim 1 , wherein the polymerization is carried out in an ether, an aromatic hydrocarbon, a chlorinated aromatic compound or a mixture of these solvents.
4. The process as claimed in claim 1 , wherein the reaction is carried out in a concentration range from 0.005 to 5 mol/L (monomer/solution volume).
5. The process as claimed in claim 1 , wherein the bases used are alkali metal hydroxides, alkali metal alkoxides or organic amines or amides, or else alkali metal hydrides or metal organyls, provided that the solvents used are not DMSO, alcohols or chlorinated solvents.
6. The process as claimed in claim 1 , wherein the amount of the base used is in the range from 2 to 10 equivalents (based on one equivalent of monomer).
7. The process as claimed in claim 1 , wherein for the compound of the formula (I):
Aryl is the same or different at each instance and is a bivalent aromatic ring system which has from 2 to 40 carbon atoms and is substituted by up to 4 substituents R 1 , or an R 1 -substituted or unsubstituted stilbenylene unit; the two substituents CHXR and CHYR are arranged in such a way that there is an even number of aromatic atoms between them; the aryl system optionally is part of a larger fused aromatic ring system; the possible substituents R 1 may potentially be situated at any free position; and
X is the same or different at each instance and is Cl, Br, I.
8. The process as claimed in claim 7 , wherein the compound of the formula (I) is selected from the formulae (II) to (XXV) which may be substituted or unsubstituted: