Alternativ-Liganden XXVIII. Neue Komplexe M(CO)4L mit Dipodliganden des Typs R2M′(OCH2PMe2)x(CH2CH2PMe2)2-x(M = Cr, Mo, W; M′ = Si, Ge; R = Me, Ph; x = 0 - 2 ) / Alternative Ligands XXVIII. Novel Complexes M(CO)4L with Dipod Ligands of the Type R2M'(OCH2PMe2)x(CH2CH2PMe2)2-x(M = Cr, Mo, W; M' = Si, Ge; R = Me, Ph; x = 0 -2)

Abstract

Abstract The coordinating properties of dipod ligands of the type R2M′(OCH2PMe2)x(CH2CH2PMe2)2-x(R = Me, Ph; M' = Si, Ge; x = 0 -2) have been investigated by the preparation of the novel cis-M (CO)4L complexes (M = Cr, Mo, W). They are obtained under mild conditions in cyclohexane or n-hexane solution by the reaction of the norbornadiene precursors M(CO)4NBD with the corresponding ligands. In case of the Ge containing ligands the dilution principle was used to improve the yields of the mononuclear derivatives. The rate of the NBD replacement is mainly determined by the central atom M (Mo > W > Cr) and only little by R, M' or x . The new com pounds have been characterized by analytical (C, H) and spectroscopic investigations (1H, 31P NMR, IR, MS). The ligand properties are discussed on the basis of spectroscopic data (in particular coordination effects) and the molecular structure of the complexes Cr(CO)4[Ph2Si(OCH2PMe2)2] (12) and Mo(CO)4Me2Ge(CH2CH2PMe2)2] (28) obtained by X-ray diffraction studies.