Reductive carbonylation route to Co(0) and Co(I) carbonyl complexes containing bridging, chelating and cleaved diphosphazanes. Structures of [Co(CO){P(OR)(2)(NHMe)}(2){P(O)(OR)(2)}{P(H)(OR ')(2)}] (R = CH2CF3, R ' = CH2CH3), [Co-2(CO)(2){mu-MeN{P(OR)

摘要

Reduction of CoCl2 by NaBH4 in ethanol in the presence of MeN{P(OR)(2)}(2) (R = CH2CF3 L-1) and carbon monoxide at one atmospheric pressure gives an unusual mononuclear complex, [Co(CO){P(OR)(2)(NHMe)}(2){P(O)(OR)(2)} {P(H)(OR)(2)}], (R = CH2CF3, R' = CH2CH3) 1 formed by cleavage of a P-N bond and by trans esterification. When the reductive carbonylation is carried out by using Zn as the reducing agent in the presence of the diphosphazanes, MeN{P(OR)(2)}(2) (R = CH2CF3 L-1; Ph L-2), the complexes [Co-2(CO)(2)(mu-L-1)(3)] 2, [Co-2(CO)(4)(mu-L-2)(2)] 3, and [Co(CO)(eta(2)-L-2)(2)][CoCl3(thf)] 4 are isolated. All the complexes have been characterised by elemental analyses and IR, H-1- and P-31-NMR spectroscopic data. The structures of the complexes 1, 2 and 4 are confirmed by single-crystal X-ray diffraction studies. (C) 1998 Elsevier Science S.A. All rights reserved. [References: 30]