Synthesis and structural characterization of {μ 3-H(Ph)CC}FeCo 2(CO) 7dppm (dppm=Ph 2PCH 2PPh 2) and {μ 3-H(Ph)CC}FeCo 2(CO) 9− nL n [L=PPh 3 ( n=1, 2), AsPh 3 ( n=1)

Abstract

The new mixed-metal clusters {μ 3-H(Ph)CC}FeCo 2(CO) 7dppm (dppm=Ph 2PCH 2PPh 2) ( 1) and {μ 3-H(Ph)CC}FeCo 2(CO) 9− n L n [L=PPh 3, n=1 ( 2), n=2 ( 3); AsPh 3, n=1 ( 4)] have been synthesized by facile substitution reactions. The molecular structures of 1, 2 and 4 have been determined by single-crystal X-ray analysis; dppm replaces two equatorial carbonyls from two Co(CO) 3 groups, and PPh 3 and AsPh 3 replace one equatorial carbonyl from a Co(CO) 3 group, respectively. The new compounds were characterized by IR, 1H-, 31P- (for 1– 3) NMR and MS. Cyclic voltammetric behavior for 1, 2 and 4 was investigated, and the results show the order of σ-donator ability is CO<PPh 3<AsPh 3<dppm.