Inorganic Chemistry, Vol.35, No.12, 3643-3658, 1996
Solution Studies of Ru-2(O(2)Cr)(4)(N)+ Complexes (N=0, 1 O(2)Cr=octanoate, Crotonate, Dimethylacrylate, Benzoate, P-Toluate) and Solid-State Structures of Ru-2(O2C-P-Tolyl)(4)(THF)(2), (Ru-2(O2C-P-Tolyl)(4)(THF)(2))(+)(BF4)(-), and Ru-2(O2C-P-Tolyl)(4)(CH3CN)(2) - Investigations of the Axial Ligation of the Ru-2 Core
Ru-2(O2C(CH2)(6)CH3)(4) (1a) is soluble in both coordinating (THF, CH3OH, CH3CN) and noncoordinating solvents (benzene, toluene, cyclohexane, CH2Cl2), allowing its solution properties to be investigated by H-1 and C-13 NMR spectroscopy, UV/visible spectroscopy, resonance Raman spectroscopy, and cyclic voltammetry. In noncoordinating solvents, la exists as an oligomer, presumably by way of axial intermolecular -(--[Ru-2]--O--)(n)- interactions. H-1 NMR studies of 1a and [Ru-2(O2C(CH2)(6)CH3)(4)](+)[X](-)([1a](+)[X](-)) where X = Cl, BF4, or O2C(CH2)(6)CH3, indicate that both dipolar and contact mechanisms contribute to the paramagnetic shifts of the protons. Resonances for axial and equatorial ligands are shifted upfield and downfield, respectively, by a dipolar mechanism.
Keywords:RAY CRYSTAL-STRUCTURE;PROTON MAGNETIC-RESONANCE;ELECTRON-SPIN RESONANCE;W QUADRUPLE BONDS;RH-RH BOND;MOLECULAR-STRUCTURE;2-HYDROXYPYRIDINATE COMPLEXES;RU2(CARBOXYLATE)4+ COMPLEXES;ELECTROCHEMICAL PROPERTIES;TRIPLE BONDS