Preparation, Crystal Structure, and Unusually Facile Redox Chemistry of a Macrocyclic Nitrosylrhodium Complex
| Autor: | Ilia A. Guzei, Wenjing Song, Andreja Bakac, Arkady Ellern, Kathleen E. Kristian |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Macrocyclic Compounds
Aqueous solution Chemistry Spectrum Analysis Inorganic chemistry Crystal structure Crystallography X-Ray Redox Reversible reaction Inorganic Chemistry Kinetics Crystallography Yield (chemistry) Organometallic Compounds Moiety Rhodium Qualitative inorganic analysis Physical and Theoretical Chemistry Oxidation-Reduction Equilibrium constant |
| Zdroj: | Inorganic Chemistry. 49:7182-7187 |
| ISSN: | 1520-510X 0020-1669 |
| Popis: | The reaction between NO and L(2)(H(2)O)Rh(2+) (L(2) = meso-Me(6)-1,4,8,11-tetraazacyclotetradecane) generates a sky-blue L(2)(H(2)O)RhNO(2+), a {RhNO}(8) complex. The crystal structure of the perchlorate salt features a bent Rh-N-O moiety (122.1(11)(o)), short axial Rh-NO bond (1.998(12) A) and a strongly elongated Rh-OH(2) (2.366(6) A) trans to NO. Acidic aqueous solutions of L(2)(H(2)O)RhNO(2+) are stable for weeks, and are inert toward oxygen. The complex is oxidized rapidly and reversibly with Ru(bpy)(3)(3+), k(f) = (1.9 +/- 0.1) x 10(5) M(-1) s(-1), to an intermediate believed to be L(2)(H(2)O)RhNO(3+). This unprecedented {RhNO}(7) species has a lifetime of about 90 s at room temperature at pH 0. The reverse reaction between L(2)(H(2)O)RhNO(3+) and Ru(bpy)(3)(2+) has k(r) = (1.5 +/- 0.4) x 10(6) M(-1) s(-1). The kinetic data define the equilibrium constant for the L(2)(H(2)O)RhNO(2+)/Ru(bpy)(3)(3+) reaction, K = k(f)/k(r) = 0.13, and yield a reduction potential for the L(2)(H(2)O)RhNO(3+/2+) couple of 1.31 V. Both the redox thermodynamics of L(2)(H(2)O)RhNO(3+/2+) and the kinetics of the reactions with Ru(bpy)(3)(3+/2+) are quite similar to those of uncoordinated NO(+)/NO. |
| Databáze: | OpenAIRE |
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