residue wherein residues R10 are independently selected from hydrogen atoms and C1-C3 alkyl groups, and residues R11 are independently selected from C1-C6 alkyl groups which are optionally interrupted by 1 to 2 hetero atoms and which are optionally substituted by 1 to 3 hydroxyl groups, and r is an integer of 1 to 3, or g) X is a residue ???(C(R92))n???W, wherein each R9 is independently hydrogen