| abstract |
A compound where n is 0, 1, 2 or 3; R1, R2, R7 and R8 are each independently an alkyl group, including cycloalkyl, an alkyl aryl group, or an aryl group, optionally with heteroatoms, with the proviso that R1 and R2 together can form a cycloalkylene group and, independently, R7 and R8 together can form a cycloalkylene group; Y is an oxygen free radical, a sulfide free radical, OR9 or SR9; R3, R4, R5, R6 and R9 are each independently H or an alkyl group, a cycloalkyl group, an aryl group, or an alkylaryl group, optionally with heteroatoms. (see formula). |