The development of new ligands for specific catalytic applications is of continuous interest in both academia and industry. Literature precedents of nickel complexes with diphosphine and diimine ligands show that minor modifications in either electronic or steric properties can make a significant difference in the rate of such an important catalytic process as CO/R migratory insertion in CO/CH2=CH2 copolymerization catalysis. In nature, a C-C coupling reaction is observed in the active site of acetyl-CoA synthase, which contains an N1N2S2 unit as a """"""""ligand"""""""" to a second nickel. It is our hypothesis that the discovery of multimetallic complexes containing NIN2S2 signals nature's use of a metallothiolato ligand to facilitate organometallic chemistry. It has inspired development of such ligands in model chemistry. Structural studies of polynuclear aggregates of Ni-1 and Ni-1* with added exogenous metals, Nill and Cul, find comparisons with diphosphines. Preliminary studies of the donor ability of the metallothiolate ligands will be determined by means of (CO) stretching frequencies utilizing W(CO)4(L2) complexes. The electrochemisty of NiN2S2W(CO)4 complexes will be discussed and the reactivity compared to traditional ligands. ? ?
Jeffery, Stephen P; Green, Kayla N; Rampersad, Marilyn V et al. (2006) NiN(2)S(2) complexes as metallodithiolate ligands to Rh(I), Rh(II) and Rh(III). Dalton Trans :4244-52 |
Rampersad, Marilyn V; Jeffery, Stephen P; Golden, Melissa L et al. (2005) Characterization of steric and electronic properties of NiN2S2 complexes as S-donor metallodithiolate ligands. J Am Chem Soc 127:17323-34 |