X-ray Structures, Photophysical Characterization, and Computational Analysis of Geometrically Constrained Copper(I)-Phenanthroline Complexes
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- 作者：John Cody ; Jeanette Dennisson ; Joshua Gilmore ; Donald G. VanDerveer ; Maged M. Henary ; Alan Gabrielli ; C. David Sherrill ; Yiyun Zhang ; Chia-Pin Pan ; Clemens Burda ; and Christoph J. Fahrni
- 刊名：Inorganic Chemistry
- 出版年：2003
- 出版时间：August 11, 2003
- 年：2003
- 卷：42
- 期：16
- 页码：4918 - 4929
- 全文大小：378K
- 年卷期：v.42,no.16(August 11, 2003)
- ISSN：1520-510X
文摘
A series of three geometrically constrained C2-symmetric Cu(I) mono-phenanthroline complexes were characterizedby X-ray structural analysis, and their photophysical properties were investigated by absorption and emissionspectroscopy. Visible light excitation yielded metal-to-ligand charge-transfer (MLCT) excited states with luminescencelifetimes up to 155 ns. Ultrafast transient absorption spectroscopy provided further insights into the excited-statedynamics and suggests for all three complexes the formation of a phenanthroline radical anion. In agreement withelectrochemical measurements, the data further indicate that coordinative rearrangements are involved in nonradiativedeactivation of the excited states. According to time-dependent density functional theory calculations (B3LYP/6-31G**), the major MLCT transitions are polarized along the C2 axis of the complex and originate predominantlyfrom the copper dxz orbital. The computational analysis identifies an excited-state manifold with a number of close-lying, potentially emissive triplet states and is in agreement with the multiexponential decay kinetics of the MLCTluminescence. The relationship between structural and photophysical data of the studied Cu(I) mono-phenanthrolinecomplexes agrees well with current models describing the photophysics of the related Cu(I) bis-diimine complexes.