The co-ordination chemistry of tris(3,5-dimethylpyrazolyl)methane manganese carbonyl complexes: Synthetic, electrochemical and DFT studies

摘要: The tricarbonyl [Mn(CO)3{HC(pz′)3}][PF6] 1+[PF6]− (pz′ = 3,5-dimethylpyrazolyl) reacts with a range of P-, N- and C-donor ligands, L, in the presence trimethylamine oxide to give [Mn(CO)2L{HC(pz′)3}]+ {L PEt33+, P(OEt)34+, P(OCH2)3CEt 5+, py 6+, MeCN 7+, CNBut8+ CNXyl 9+}. complex [Mn(CO)2(PMe3){HC(pz′)3}]+2+ is formed by reaction 7+ PMe3. Complexes 2+ 6+ were structurally characterised X-ray diffraction methods. Reaction half molar equivalent 4,4′-bipyridine gives purple compound assumed be bridged dimer [{HC(pz′)3}Mn(CO)2(μ-4,4′-bipy)Mn(CO)2{HC(pz′)3}]2+102+. relative electron donating ability HC(pz′)3 has been established comparison cyclopentadienyl tris(pyrazolyl)borate analogues. Cyclic voltammetry shows that each complexes undergoes an irreversible oxidation. correlation between average carbonyl stretching frequency oxidation potential for P- ligands coincident observed [Mn(CO)3−mLm(η-C5H5−nMen)]. data N-donor however, are not due node (and phase change) metal HOMO as suggested preliminary DFT calculations.