Transition metal complexes with thiosemicarbazide-based ligands. LIII. [4-(2-Diphenylphosphino-alpha-ethoxybenzyl-kappaP)-S-methyl-1-(4-oxidopent-3-en-4-ylidene-kappaO)thiosemicarbazido-kappa(2)N(1),N(4)]nickel(II).