Synthesis, characterization and catalytic applications of rhodium(I) organometallics with substituted tertiary phosphines

Organometallics of the type [Rh(COD)(L)Cl] (where, L = carboxyl/formyl/pyridyl tertiary phosphines) have been synthesized by treating the precursor [Rh(COD)Cl]2 with substituted tertiary phosphines. [Rh(COD)(Ph2P-2-C6H4COO)] and [Rh(COD)(Ph2P-CH2COO)] were synthesized by halide abstraction from the precursor [Rh(COD)Cl]2 in the presence of AgPF6 in tetrahydrofuran by involving 2-carboxy phenyl/carboxy methyl group of tertiary phosphines in coordination as bidentate ligands. Similarly, the cationic compounds of the type [Rh(COD)L2]PF6 were also synthesized by treating [Rh(COD)Cl]2 in the presence of AgPF6. All these compounds were characterized by elemental analysis, conductance measurements, IR, 1H, 13C, 31P NMR, mass, and electronic spectral studies. [Rh(COD)(Ph2-P-2-C6H4COOH)Cl] and [Rh(COD)(Ph2-P-2-C6H4COO)] were studied on the catalytic reduction reactions of 2-nitroanisole, 3-nitro anisole, 4-nitroanisole, 2-nitrobenzoicacid, 3-nitrobenzoicacid, 4-nitrobenzoicacid under mild conditions and [Rh(COD)(Ph2-P-2-C6H4COO)] was found to be more efficient than [Rh(COD)(Ph2-P-2-C6H4COOH)Cl].