CHROMIUM AND MOLYBDENUM COMPLEXES OF TERTIARY ALKYL AND PENDANT DONORTRIPHOSPHAMACROCYCLES

The first tritertiary (1,5,9-triphosphacyclododecane)chromium(0) compl exes have been prepared from the secondary phosphine macrocycle precur sor complex arbonyl(1,5,9-stiphosphacyclododecane)chromium(0), and the range of molybdenum(0) complexes with tritertiary 1,5,9-triphosphacyc lododecane ligands has been extended. The synthetic routes involve eit her deprotonation of the secondary phosphine precursor followed by alk ylation with alkyl halide or by radical-catalysed hydrophosphination o f selected alkenes. These routes are general and allow access to a ran ge of macrocyclic triphosphines with alkyl functions or with alkyl arm s containing pendant donor functions (N, P, O, S) attached to phosphor us fdr both chromium and molybdenum. All compounds have been spectrosc opically and analytically characterised.