Inorganic Chemistry, Vol.35, No.23, 6724-6734, 1996
Oxo-Centered Mixed-Ligand Triruthenium Complexes Having Redox-Active N-Methyl-4,4’-Bipyridinium Ions (Mbpy(+)) - Reversible Multistep Electrochemical Properties of (Ruiii2Ruii(Mu(3)-O)(Mu-Ch3Co2)(6)(Mbpy(+))(2)(Co))(2+) and (Ruiii3(Mu(3)-O)(Mu-Ch3Co2)(6)(Mbpy(+))(2)(L))(3+) (L=h2O and N-Heterocyclic Ligands)
A new series of oxo-centered acetate-bridged triruthenium comlexes having two redox-active N-methyl-4,4’-bipyridinium ions (mbpy(+)) have been prepared, and their reversible multistep and multielectron electrochemical properties are reported : [(Ru2RuII)-Ru-III(mu(3)-O)mu-CH3CO2)(6)(mbpy(+))(2)(CO)](2+) and [Ru-3(III)(mu(3)-O)mu-CH3CO2)(6)(mbpy(+))(2)- (L)](3+) (L = H2O, pyrazine (pz), pyridine (py), imidazole (Him), and 4-(dimethylamino)pyridine (dmap)). Among these series, the CO complex, [(Ru2RuII)-Ru-III(mu(3)-O)mu-CH3CO2)(6)(mbpy(+))(2)(CO)](ClO4)(2) . 2DMF (1b . 2DMF) was structurally characterized by X-ray crystallography. 1b . 2DMF crystallizes in the monoclinic space group P2(1)/m (No. 11) with a = 8.740(6) Angstrom, b = 32.269(6) Angstrom, c = 10.276(4) Angstrom, beta = 103.37(5)degrees, V = 2820(2) Angstrom(3), Z = 2, d(calcd) = 1.636 g cm(-3), and R = 0.071 (R(w) = 0.074) for 5277 independent reflections (F-o > 3 sigma(F-o). The (CO)- Ru ... Ru distance (3.410(2) Angstrom) is appreciably longer than the other Ru ... Ru distance (3.276(2) Angstrom), indicating that the trinuclear core is in the valence-trapped (Ru2RuII)-Ru-III(CO) oxidation state. : [(Ru2RuII)-Ru-III(mu(3)-O)mu-CH3CO2)(6)(mbpy(+))(2)(CO)](2+) and [Ru-3(III)(mu(3)-O)mu-CH3CO2)(6)(mbpy(+))(2)- (L)](3+) (L = H2O, pyrazine (pz), pyridine (py), imidazole (Him), and 4-(dimethylamino)pyridine (dmap)). Among these series, the CO complex, [(Ru2RuII)-Ru-III(mu(3)-O)mu-CH3CO2)(6)(mbpy(+))(2)(CO)](ClO4)(2) . 2DMF (1b . 2DMF) was structurally characterized by X-ray crystallography. 1b . 2DMF crystallizes in the monoclinic space group P2(1)/m (No. 11) with a = 8.740(6) Angstrom, b = 32.269(6) Angstrom, c = 10.276(4) Angstrom, beta = 103.37(5)degrees, V = 2820(2) Angstrom(3), Z = 2, d(calcd) = 1.636 g cm(-3), and R = 0.071 (R(w) = 0.074) for 5277 independent reflections (F-o > 3 sigma(F-o). The (CO)- Ru ... Ru distance (3.410(2) Angstrom) is appreciably longer than the other Ru ... Ru distance (3.276(2) Angstrom), indicating that the trinuclear core is in the valence-trapped (Ru2RuII)-Ru-III(CO) oxidation state.
Keywords:BRIDGED TRINUCLEAR RUTHENIUM;DINUCLEAR RUTHENIUM;MANGANESE COMPLEXES;PHYSICAL-PROPERTIES;MAGNETIC-PROPERTIES;ELECTRON-TRANSFER;PHASE-TRANSITION;METAL-COMPLEXES;ACETATE CLUSTER;HEAT-CAPACITY