TRANSITION-METAL CHEMISTRY OF MAIN GROUP HYDRAZIDES .1. SYNTHESIS AND CHARACTERIZATION OF CYCLOMETALLAPHOSPHOHYDRAZIDES OF COBALT(I), COPPER(I), AND PALLADIUM(II) - X-RAY STRUCTURES OF COBALT(I) AND PALLADIUM(II) REPRESENTATIVES

The reactions of the phosphohydrazide PhP(S)(NMeNH2)2 (1) with the perchlorates of Co(II) and Cu(II) led to the formation of spirocyclic cyclometallaphosphohydrazides containing Co(I) (2) and Cu(I) (3) metal centers. Compound 1 in its reaction with PdCl2(PhCN)2 produced the Pd(II) metallacycle 4 wherein coordination with the metal center occurs through P=S and one of the hydrazine -NH2 units. Phosphohydrazide 1 undergoes Schiff base reactions with aromatic- and aliphatic-substituted aldehydes such as salicylaldehyde and piperazinecarboxaldehyde to give new phosphohydrazide ligands 5 and 6, respectively, in high yields. The Pd(II) metallacycles 7 and 8 obtained from the reactions of 5 and 6 respectively showed similar ligating characteristics as in 4. The structural elucidation of all the new ligands and the cyclometallaphosphohydrazides has been done by analytical and complete NMR (H-1, P-31) and IR spectroscopic data. The structures of 2 and 7 were further confirmed by X-ray diffraction study. Crystal data for 2: monoclinic space group P2(1)/c, a = 12.362 (4) angstrom, b = 11.013 (9) angstrom, c = 10.842 (3) angstrom, beta = 100.08 (9)-degrees, Z = 4. Crystal data for 7: triclinic space group P1BAR, a = 9.491 (3) angstrom, b = 11.480 (20) angstrom, c = 12.896 (4) angstrom, beta = 88.170 (15)-degrees, Z = 2. The structures were solved by direct methods and were refined to R = 0.030 and 0.028 for 2 and 7 respectively.