Bi- and poly-metallic cyanide-bridged complexes of the redox-active cyanomanganese nitrosyl unit [Mn(CN)(PR3)(NO)(eta-C5H4Me)].
Cationic nitrile complexes and neutral halide and cyanide complexes, with the general formula [MnL1L2(NO)(eta-C5H4Me)]z, undergo one-electron oxidation at a Pt electrode in CH2Cl2. Linear plots of oxidation potential, Eo', vs. nu(NO) or the Lever parameters, EL, for L1 and L2, allow Eo' to be estimated for unknown analogues. In the presence of TlPF6, [MnIL'(NO)(eta-C5H4Me)] reacts with [Mn(CN)L(NO)(eta-C5H4Me)] to give [(eta5-C5H4Me)(ON)LMn(mu-CN)MnL'(NO)(eta5-C5H4Me)][PF6] which undergoes two reversible one-electron oxidations; DeltaE, the difference between the potentials for the two processes, differs significantly for stable cyanide-bridged linkage isomers. Novel pentametallic complexes such as [Mn[(mu-NC)Mn(CNBut)(NO)(eta5-C5H4Me)]4(OEt2)][PF6]2 and [Mn[(mu-NC)Mn(CNXyl)(NO)(eta5-C5H4Me)]4(NO3-O,O')][PF6], containing a trigonal bipyramidal and a distorted octahedral Mn(II) centre, respectively, result either from slow decomposition of the binuclear cyanide-bridged species or from the reaction of anhydrous MnI2 with four equivalents of [Mn(CN)L(NO)(eta5-C5H4Me)] in the presence of TlPF6.
Adams
Christopher J
CJ
School of Chemistry, University of Bristol, Bristol, UK BS8 1TS.
Anderson
Kirsty M
KM
Bardaji
Manuel
M
Connelly
Neil G
NG
Goodwin
Nicholas J
NJ
Llamas-Rey
Estefania
E
Orpen
A Guy
AG
Rieger
Philip H
PH
D001952:Bridged-Ring Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003486:Cyanides / Q000737:chemistry*; D004563:Electrochemistry; D008024:Ligands; D008345:Manganese / Q000737:chemistry*; D008958:Models, Molecular; D009603:Nitroso Compounds / Q000737:chemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010084:Oxidation-Reduction
D001952:Bridged-Ring Compounds; D003486:Cyanides; D008024:Ligands; D009603:Nitroso Compounds; D009942:Organometallic Compounds; D008345:Manganese