| abstract |
Compounds of the formula (I), wherein A 1 is formula (II); A 2 is formula (III); A 3 is formula (IV); A 4 is formula (V); w, x, y and z independently of each other are an integer from 0-4, provided that the sum of x+y+z is an integer from 2-4, corresponding to the valency of Q; M 1 , M 2 , M 3 and M 4 for example are a direct bond, CO or O; Y for example is a direct bond or S; Q is a (x+y)-valent linking group; R 1 is for example hydrogen, C 1 -C 20 alkyl or phenyl or naphthyl; R 2 and R″ 2 for example are is hydrogen or C 1 -C 20 alkyl; R 3 , R 4 , R′ 3 , R′ 4 , R″ 3 and R″ 4 for example are hydrogen, halogen, phenyl, or C 1 -C 20 alkyl; and R 24 is for example a direct bond; exhibit an unexpectedly good performance in photopolymerization reactions. |