The 1H-NMR spectra of complexes involving the paramagnetic metal center [(NH3)5RuIII] coordinated at ring nitrogens have been examined with pyridine, purine, nucleoside, and nucleotide ligands along with 31P-NMR of the nucleotide complexes and EPR of representative complexes. Variations in the spectra have been investigated as a function of the coordination site and pH. Pseudocontact and contact shifts have been calculated for various protons, and an attempt has been made to correlate sugar conformations in coordinated 5′GMP, 5′IMP, Guo, and Ino with paramagnetically induced shifts. The compound [(7MeGUaκN9)(NH3)5Ru]Cl 3·3H2O crystallizes in the orthorhombic space group Pna21 with cell parameters a = 25.375(4) Å, b = 11.803(4) Å, c = 6.958(2) Å, Z = 4, and R = 0.042. The autoxidation of [L(NH3)5RuIII], where L = Guo, dGuo, and 1MeGuo, to the corresponding 8-oxo complexes under atmospheric oxygen is first order in the complex and [OH-]. For L = Guo, k = 6.6 × 10-5 M-1 s-1, ΔH* = 58 kJ/mol, and ΔS* = -124 J/(mol K).
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry