Patent ID: 6872863

Claim:
A ligand of formula (II): wherein the substituents R 1 and R 2 , the same or different from each other, are selected from the group consisting of linear or branched, C 1 -C 20 aliphatic hydrocarbon, C 3 -C 20 cycloalkyl, C 6 -C 20 aryl, C 7 -C 20 alkylaryl and C 7 -C 20 arylalkyl radicals, optionally containing one or more atoms belonging to groups 13-17 of the Periodic Table of the Elements, —OR, —SR, —NR 2 , N-pyrrolyl, N-indolyl, —PR 2 , —BR 2 and —SiR 3 groups; m is an integer ranging from 0 to 2; n is an integer ranging from 0 to 4; with the proviso that, when m is 0, then n is different from 0.