Chromium and molybdenum complexes of tertiary alkyl and pendant donor triphosphamacrocycles

Abstract

The first tritertiary (1,5,9-triphosphacyclododecane)chromium(0) complexes have been prepared from the secondary phosphine macrocycle precursor complex tricarbonyl(1,5,9-stiphosphacyclododecane)chromium(0), and the range of molybdenum(0) complexes with tritertiary 1,5,9-triphosphacyclododecane ligands has been extended. The synthetic routes involve either deprotonation of the secondary phosphine precursor followed by alkylation with alkyl halide or by radical-catalysed hydrophosphination of selected alkenes. These routes are general and allow access to a range of macrocyclic triphosphines with alkyl functions or with alkyl arms containing pendant donor functions (N, P, O, S) attached to phosphorus for both chromium and molybdenum. All compounds have been spectroscopically and analytically characterised.