Carboxylation of a μ₃-Diazo Methylidyne Triosmium Cluster

Abstract

The unsaturated cluster Os 3 (CO) 8 (Ph 2 PCH 2 P(Ph)C 6 H 4 )(μ-H) ( 1 ) reacts with CH 2 N 2 at −10 to 25 °C to give two novel compounds Os 3 (CO) 7 (μ 3 -CN 2 )(μ-dppm)(μ-H) 2 ( 2 ) and Os 3 (CO) 7 (μ 3 -CCO 2 H)(μ-dppm)(μ-H) 3 ( 3 ) characterized by single-crystal X-ray crystallography. Compound 2 is converted to 3 in almost quantitative yield by reaction with CO (atmospheric pressure) and trace H 2 O. The reaction of 2 with molecular hydrogen at atmospheric pressure at 80 °C yields Os 3 (CO) 8 (μ-dppm)(μ-H) 2 ( 4 ) and Os 3 (CO) 10 (μ-dppm) ( 5 ).