Metallocenes and a photopolymerisable composition containing them

Claim 1

A process for the preparation of a titanocene of the formula I' wherein M is a tetravalent titanium atom, both symbols R 1 independently of one another are cyclopentadienyl e , indenyl e or both symbols R 1 together are a radical of the formula II wherein X is (CH 2 ) n in which n is 1, 2 or 3, alkylidene having 2 to 12 C atoms, cycloalkylidene having 5 to 7 ring carbon atoms, SiR4 2 or SnR 4 2 , in which R 4 is C 1 -C 12 alkyl, C 5 -C 12 cycloalkyl, C 6 -C 16 aryl or C 7 -C 16 -aralkyl, the radicals cyclopentadienyl Θ , indenyl e or of the formula II being in each case unsubstituted or substituted by linear or branched alkyl, alkoxy, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, CN, halogen, amino or aminoalkyl or quaternized amino or quaternized aminoalkyl, R 2 is a 6-membered carbocyclic or 5- or 6-membered heterocyclic aromatic ring which is substituted by fluorine atoms in at least one of the two ortho-positions relative to the metal-carbon bond, or R 2 and R 3 together are a radical of the formula III in which Q is a carbocyclic or heterocyclic 5- or 6-membered aromatic ring, each of the two bonds to the titanium atom being in the ortho-position relative to the Y group and the other ortho-position relative to these bonds being substituted in each case by a fluorine atom, ad where the carbocyclic and heterocyclic ring R 2 or Q can carry optionally linear or branched alkyl, alkoxy, cycloalkyl, aryl, aralkyl, hydroxyl carboxyl, cyano, halogen, alkoxycarbonyl, aminocarbonyl, amino, quaternized amino, aminoalkyl or quaternized aminoalkyl as further substituents, and Y is CH 2 , alkylidene having 2 to 12 C atoms, cycloalkylidene having 5 to 7 ring carbon atoms, a direct bond, NR 4 , O, S, SO, S0 2 , CO, SiR 4 2 or SnR 4 2 , R 3 is alkynyl, phenylalkynyl which is unsubstituted or substituted by halogen, tertiary amino, C 1 -C 6 alkyl or C 1 -C 6 alkoxy, carboxyl, hydroxyl or cyano, or is N 3 , CN, SiR 4 3 or SnR 4 3 or has the meaning of R 2 , where, if both symbols R 1 are unsubstituted cyclopentadienyl Θ , only one of the radicals R 2 and R 3 is pentafluorophenyl; with the exception of the compounds bis-(cyclopentadienyl)-2,2'-octafluorobiphenyltitanium and bis(indenyl)-bis(pentafluorophenyl)-titanium, which comprises reacting 1 mole of a compound of the formula IV wherein R 1 and M IV are as defined in claim 1 and Z is halogen, in particular chlorine, either with 1 mole of LiR 2 or LiR 3 and subsequently with 1 mole of LiR 3 or LiR 2 , or with 2 moles of LiR 2 , where R 2 is as defined in claim 1 and R 3 is alkynyl, unsubstituted or substituted phenylalkynyl, N 3 , CN, SiR 4 3 or SnR 4 3 , and subsequently isolating the compound of the formula I in a manner known per se.