R40 and R41, even when bearing the same index, can be identical or different and are each a hydrogen atom, a C1-C40 group such as an alkyl group having from 1 to about 30 carbon atoms, an aryl group of from 6 to about 40 carbon atoms, a fluoroalkyl group of from 1 to about 10 carbon atoms, an alkoxy group of from 1 to about 10 carbon atoms, an aryloxy group of from 6 to about 10 carbon atoms, an a