Compounds of the formulae I, II, III, IV and V
##STR1##
wherein R1 i.a. is C4-C9cycloalkanoyl, C1-C12alkanoyl,
C4-C6alkenoyl, or benzoyl; R2 is for example phenyl,
C1-C20alkyl, C3-C8cycloalkyl, C2-C20alkanoyl,
or benzoyl; Ar1 is R4S-phenyl or NR5R6-phenyl,
each of which optionally is substituted; or Ar1 i.a. is
##STR2##
optionally substituted; or Ar1 is naphthyl or anthracyl each
of which is unsubstituted or substituted; or Ar1 is benzoyl, naphthalenecarbonyl,
phenanthrenecarbonyl, anthracenecarbonyl or pyrenecarbonyl, each of which is unsubstituted
or substituted, or Ar1 is 3,4,5-trimethoxyphenyl, phenoxyphenyl or biphenyl;
Ar2 i.a. is
##STR3##
optionally substituted, or naphthyl or anthracyl, each of which is unsubstituted
or substituted, x is 2 or 3; M1 when x is 2, for example is phenylene,
naphthalene, anthracylene, each of which optionally is substituted; M1,
when x is 3, is a trivalent radical; M2 for example is
##STR4##
M3 is for example C1-C12alkylene,
cyclohexylene, or phenylene; n is 1-20; R3 is for example hydrogen or
C1-C12alkyl; R3 i.a. is C1-C12alkyl;
substituted or —O-interrupted C2-C6alkyl; R4 is
for example hydrogen, or C1-C12alkyl; and R5 and
R6 independently of each other i.a. are hydrogen, C1-C12alkyl,
or phenyl; are suitable as photoinitiators in particular in resist applications.
