| abstract |
A compound represented by the formula: n n n n n n n n n n n n wherein R is selected from the group consisting of (i) substituted or unsubstituted alkyl with C=0 to 12 inclusive; (ii) substituted or unsubstituted aryl; and (iii) substituted and unsubstituted alkylaryl; n wherein X 1 , X 2 , X 3 and X 4 are each selected from the group consisting of alkyl, aryl, alkylaryl groups and hydrogen; wherein R 1 , R 2 , R 3 , and R 4 are each selected from the group consisting of alkyl, aryl, alkylaryl groups and hydrogen and R 2 and R 3 may optionally be bridged by a polymethylene group; wherein when C=0 in R, the combined group R 1 R 2 is the same as the combined group R 3 R 4 ; and wherein when C=1 in R, each of R 1 , R 2 , R 3 , and R 4 are hydrogen. |