Patent ID: 7847125

Claim:
A compound having the following general formula: wherein R 1 and R 2 together with the carbon atoms to which the are bonded are joined together to form a first substituted or unsubstituted C 3 -C 30 ring, R 3 and R 5 together with the carbon atoms to which they are bonded are joined together to form a second substituted or unsubstituted C 3 -C 30 ring, and R 4 , R 5 and R 7 are independently hydrogen, substituted or unsubstituted C 1 -C 30 alkyl group, substituted or unsubstituted C 2 -C 30 alkenyl group, substituted or unsubstituted C 3 -C 12 cycloalkyl group, substituted or unsubstituted C 5 -C 25 aryl group, substituted or unsubstituted C 6 -C 25 arylalkyl group, or substituted or unsubstituted C 1 -C 30 alkoxy group.