Solvent Effects on the Conversion of Dicopper(II) μ-η2:η2-Peroxo to Bis-μ-oxo Dicopper(III) Complexes: Direct Probing of the Solvent Interaction
| Autor: | Andreas D. Zuberbühler, Lanying Q. Hatcher, Mark J. Henson, Roger D. Sommer, Edward I. Solomon, Susan Kaderli, Hong-Chang Liang, Kenneth D. Karlin, Michael A. Vance, David Lahti, Arnold L. Rheingold, Christiana Xin Zhang |
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| Rok vydání: | 2004 |
| Předmět: |
Molecular Structure
Stereochemistry Crystallography X-Ray Spectrum Analysis Raman Medicinal chemistry Adduct Oxygen Inorganic Chemistry Solvent chemistry.chemical_compound chemistry Organometallic Compounds Solvents Acetone Reactivity (chemistry) Physical and Theoretical Chemistry Solvent effects Diethyl ether Methylene Copper Tetrahydrofuran |
| Zdroj: | Inorganic Chemistry. 43:4115-4117 |
| ISSN: | 1520-510X 0020-1669 |
| DOI: | 10.1021/ic0498283 |
| Popis: | A new tridentate ligand, PYAN, is employed to investigate solvent influences for dioxygen reactivity with [Cu(PYAN)(MeCN)]B(C(6)F(5))(4) (1). Stopped-flow kinetic studies confirm that the adducts [[u(II)(PYAN)]2)(O(2))][B(C(6)F(5))(4)](2) (2(Peroxo)) and [[u(III)(PYAN)]2)(O)(2)][B(C(6)F(5))(4)](2) (2(Oxo)) are in rapid equilibrium. Thermodynamic parameters for the equilibrium between 2(Peroxo) and 2(Oxo) re as follows: THF, deltaH degrees approximately -15.7 kJ/mol, deltaS degrees approximately -83 J/K.mol; acetone, deltaH degrees approximately -15.8 kJ/mol, deltaS degrees approximately -76 J/K.mol. UV-visible absorption and resonance Raman spectroscopic signatures demonstrate that the equilibrium is highly solvent dependent; the mixture is mostly 2(Peroxo) in CH(2)Cl(2), but there are significantly increasing quantities of 2(Oxo) along the series methylene chloride --diethyl ether --acetone --tetrahydrofuran (THF). Copper(II)-N(eq) stretches (239, 243, 244, and 246 cm(-)(1) in CH(2)Cl(2), Et(2)O, acetone, and THF, respectively) are identified for 2(Peroxo), but they are not seen in 2(Oxo), revealing for the first time direct evidence for solvent coordination in the more open 2(Peroxo) structure. |
| Databáze: | OpenAIRE |
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