1 H and 31 P NMR and EPR of Pentaammineruthenium(III)Complexes of Endocyclically Coordinated Nucleotides, Nucleosides, and Related Heterocyclic Bases. Autoxidation of [(Guoκ N7 )(NH 3 ) 5 Ru III ] (Guo = Guanosine). Crystal Structure of [7MeGuaκ N9 (NH 3 ) 5 Ru]Cl 3 ·3H 2 O

V. M. Rodriguez-Bailey, K. J. LaChance-Galang, Peter E Doan, M. J. Clarke*

*Corresponding author for this work

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Abstract

The 1 H-NMR spectra of complexes involving the paramagnetic metal center [(NH 3 ) 5 Ru III ] coordinated at ring nitrogens have been examined with pyridine, purine, nucleoside, and nucleotide ligands along with 31 P-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 [(7MeGUaκ N9 )(NH 3 ) 5 Ru]Cl 3 ·3H 2 O crystallizes in the orthorhombic space group Pna2 1 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(NH 3 ) 5 Ru III ], 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).

Original languageEnglish (US)
Pages (from-to)1873-1883
Number of pages11
JournalInorganic Chemistry
Volume36
Issue number9
Publication statusPublished - Apr 23 1997

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ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

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