Syntheses, structures and spectroscopic properties of a novel series of metalmetal bonded complexes Ru(E)(E′)(CO) 2( iPrDAB): (E  Br, E′  Mn(CO) 5; E  SnPh 3, E′  Mn(CO) 5, Re(CO) 5, CO(CO) 4; E  Me, E′  Re(CO) 5; E  E′  Mn(CO) 5, Re(CO) 5; iPrDAB  N, N′-diisopropyl-1,4-diaza-1,3-butadiene)

Abstract

This article describes the syntheses, structures and spectroscopic (IR, Raman, NMR, visible absorption) properties of novel metalmetal bonded complexes of the type trans,cis-Ru(E)(E′)(CO) 2( iPrDAB) in which E  Br, Me, SnPh 3, Mn(CO) 5 or Re(CO) 5 and E′  Mn(CO) 5, Re(CO) 5 or Co(CO) 4 (depending on E). The structures of Ru(SnPh 3)(Mn(CO) 5)(CO) 2( iPrDAB) Ru(SnPh 3)(Co(CO) 4)(CO) 2( iPrDAB) and Ru(Re(CO) 5) 2(CO) 2( iPrDAB) were determined by single crystal X-ray diffraction. The complexes have a distorted octahedral geometry with E and E′ in axial positions. The structure of Ru(SnPh 3)(Co(CO) 4)(CO) 2( iPrDAB) is noteworthy, since one of the carbonyl ligands of the Co(CO) 4 group forms a semi-bridge with Ru. The IR and Raman spectra in the ν(CO) and ν s (CN) wavenumber region are assigned. The absorption spectra show one or two charge-transfer bands in the visible region, their position and number depending on E and E′. The SnPh 3-complexes show in the 1H NMR spectra a large 4J( 117 119 Sn,H) coupling constant for the imine protons of their iPrDAB ligands, which points to a strong delocalisation of charge within these complexes.