Patent ID: 7767840

Claim:
A compound of formula IIA or IIB: wherein R 1 and R 2 are independently chosen from alkyl, alkenyl, alkynyl or aryl; each R 3 is independently chosen from (C 1 -C 12 )alkyl, alkenyl, alkynyl and aryl; each R 4 is independently chosen from branched and cyclic (C 3 -C 5 )alkyl; each R 5 is independently chosen from (C 1 -C 12 )alkyl, alkenyl, alkynyl and aryl; X is halogen; a′=0-3; b′=1-2; c′=1-3; d′=0-3; a′+b′+c′+d′=4; a″=0-2; b″=1-2; e″=1-2; f″=0-2; a″+b″+e″+f″=4; wherein at least two of a″, b″ and f″≠0.