Heterometallic complexes containing 1,1′-(C≡C)₂Fc′ units linking two different metal centres

Abstract

Proto-desilylation of 1-(Me3SiC{triple bond, long}C)-1′-{Cp*(dppe)RuC{triple bond, long}C}Fc′ (1) afforded the corresponding ethynyl derivative 2, from which the green Co2(μ-dppm)n(CO)8-2n (n = 0, 1) adducts 3 and 4 were obtained. Replacement of the ethynyl proton in reactions between 2 and AuCl(PPh3), Hg(OAc)2 or FeCl(dppe)Cp* gave complexes 1-(RC{triple bond, long}C)-1′-{Cp*(dppe)RuC{triple bond, long}C}Fc′ [R = Au(PPh3) 5, 1/2Hg 6, Fe(dppe)Cp* 8]; the latter gave bis-vinylidene 9 with MeI, characterised (as was 2) by a single crystal X-ray study. Oxidative coupling of 2 (CuCl/tmeda/acetone, air) gave diyne 10, while coupling of 5 with Co3(μ3-CBr)(μ-dppm)(CO)7 afforded 1-{Cp*(dppe)RuC{triple bond, long}C}-1′-{(OC)7(μ-dppm)Co3(μ3-CC{triple bond, long}C)}Fc′ (11). Cyclic voltammetric measurements indicated that there was no significant electronic coupling between the end-groups through the ferrocene centre in any of these compounds. © 2006 Elsevier B.V. All rights reserved.