Non-photochemical synthesis of Re(diimine)(CO)2(L)Cl (L = phosphine or phosphite) compounds

• Non-photochemical synthesis of Re(diimine)(CO)2(L)Cl compounds (L = P(OEt)3, PMe3)
• Effect of ligand variation (displaying scope of synthetic method)
• Characterization of three new Re(diimine)(CO)2(L)Cl compounds
• X-ray crystallographic structure ReCl(4,4′-di-tertbutyl-2,2′-bipyridine)(CO)2P(OEt)3

The synthesis and characterization of a series of compounds of the type Re(diimine)(CO)2(L)Cl (where L = P(OEt)3, PMe3) is reported. The non-photochemical ligand substitution (non-PLS) utilizes the trans-labilizing effect of phosphorus ligands to facilitate carbonyl replacement. The non-PLS pathway leads to good yields (> 60%) of single isomer products, comparing favorably to the lower yield, mixed isomer products of analogous PLS pathways. The substitution of a carbonyl group by a phosphine/phosphite ligands shifts absorption further into the visible region without diminishing molar absorptivity. The synthesis presented provides a general facile ligand substitution pathway for related light-sensitive neutral rhenium/manganese carbonyl halide compounds.

A generalized reaction is shown for the primary products of the paper. A light bulb is crossed-out to indicate that the synthesis is non-photochemical in nature. Below this are sample UV/vis spectra (highlighting the bathochromic shift upon ligand substitution).Figure optionsDownload as PowerPoint slide