Synthesis and characterization of osmium nitrosyl porphyrins containing organo, halogeno, and μ-oxo ligands, and extensions to the first organometallic thionitrosyl porphyrin

The sequential reaction of (OEP)Os(CO) with NOPF6 (in CH2Cl2) followed by RMgX (in THF) gives variable isolated yields of the new (OEP)Os(NO)R (5-44%), (OEP)Os(R)(2) (1-10%), (OEP)Os(NO)X (14-19%), and [(OEP)Os(NO)](2)(mu-O) (up to 24%) compounds, depending on the reaction conditions and the nature of R and X (OEP = octaethylporphyrinato dianion; R = Me, Et, Pr-i, Bu-t, p-C6H4F; X = Cl, Br). The IR v(NO) values of the complexes (in CH2Cl2) decrease in the order (OEP)Os(NO)X(1799-1795 cm(-1)) > [(OEP)Os(NO)](2)(mu-O) (1770 cm(-1)) > (OEP)Os(NO)R (1748-1703 cm(-1)). The delta(meso) peaks in the H-1 NMR spectra of the (OEP)Os complexes (in CDCl3) also decrease in the order (OEP)Os(NO)X (10.41-10.40 ppm) > [(OEP)Os(NO)](2)(mu-O) (10.35 ppm) > (OEP)Os(NO)R (10.24-10.21 ppm) > (OEP)Os(R)(2) (9.71-9.03 ppm). The thionitrosyl (OEP)Os(NS)Cl and (OEP)Os(NS)Me compounds have also been prepared. The solid-state molecular structures of [(OEP)Os(NO)](2)(mu-O), (OEP)Os(NS)Cl, and (OEP)Os(NS)Me have been determined by single-crystal X-ray diffraction.