Syntheses and Structures of Tungsten<i>o</i>-(Diphenylphosphino)benzaldehyde Complexes Bearing π-Bonded Aldehyde Groups

Abstract

Reaction of the bidentate ligand Ph 2 P( o -C 6 H 4 )C( O)H (abbreviated as PCHO) with W(CO) 3 (η 3 -(MeNCH 2 ) 3 ) at room temperature affords W(CO) 3 (η 1 -PCHO)(η 3 -PCHO) ( 1 ), which subsequently loses a carbonyl ligand to give W(CO) 2 (η 3 -PCHO) 2 ( 2 ). Further treatment of 2 with PCHO in refluxing benzene results in carbon−carbon coupling of the PCHO ligands to produce W(CO)(η 3 -PCHO)(η 3 -(PCHO) 2 ) ( 3 ). The structures of 1 − 3 have been determined by an X-ray diffraction study. The PCHO ligands in these compounds act as chelating phosphine−aldehydes with the aldehyde groups coordinating in a π fashion.