Spectroscopic and Theoretical Studies of Oxygenated Dicopper(I) Complexes Containing Hydrocarbon-Linked Bis[2-(2-pyridyl)ethyl]amine Units: Investigation of a Butterfly [Cu2(
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- 作者：Elna Pidcock ; Honorio V. Obias ; Masaaki Abe ; Hong-Chang Liang ; Kenneth D. Karlin ; and Edward I. Solomon
- 刊名：Journal of the American Chemical Society
- 出版年：1999
- 出版时间：February 17, 1999
- 年：1999
- 卷：121
- 期：6
- 页码：1299 - 1308
- 全文大小：174K
- 年卷期：v.121,no.6(February 17, 1999)
- ISSN：1520-5126
文摘
A series of side-on peroxide-bridged binuclear copper complexes [Cu2(NnPY2)(O2)]2+ (where n =3-5), which have been proposed to adopt a butterfly Cu2O2 geometry due to the constraints placed on theCu-Cu distance by the alkyl chain linker of length -(CH2)n-, have been studied using absorption and resonanceRaman spectroscopy and theoretical techniques. The four components of the peroxide to copper(II) charge-transfer transitions have been identified for the first time in the [Cu2(NnPY2)(O2)]2+ (where n = 3-5) complexes.The observed shift of the peroxide O-O stretch by 25 cm-1 to higher energy and the changes observed in theenergy and intensity of absorption bands including the presence of an additional band at 23 800-20 400 cm-1(420-490 nm) (not seen in planar side-on peroxide-bridged dicopper cores) are correlated to the butterflystructure using transition dipole vector coupling and valence bond configuration interaction models. Theidentification of an absorption band at 23 800-20 400 cm-1 (420-490 nm) associated with the butterfly side-on peroxide-bridged dicopper core is important since the isomeric, bis(
-oxo) core is also characterized by anabsorption band in this region. The changes in bonding associated with a butterfly distortion of the Cu2O2core are defined, and the reactivity of the butterfly core with respect to electrophilic aromatic substitution andH atom abstraction reactions is compared with that of the planar side-on peroxide-bridged dicopper core usingthe frontier molecular orbital description.
-oxo) core is also characterized by anabsorption band in this region. The changes in bonding associated with a butterfly distortion of the Cu2O2core are defined, and the reactivity of the butterfly core with respect to electrophilic aromatic substitution andH atom abstraction reactions is compared with that of the planar side-on peroxide-bridged dicopper core usingthe frontier molecular orbital description.