121114-64-5Relevant articles and documents
X-ray structures, photophysical characterization, and computational analysis of geometrically constrained copper(I) -Phenanthroline complexes
Cody, John,Dennisson, Jeanette,Gilmore, Joshua,VanDerveer, Donald G.,Henary, Maged M.,Gabrielli, Alan,Sherrill, C. David,Zhang, Yiyun,Pan, Chia-Pin,Burda, Clemens,Fahrni, Christoph J.
, p. 4918 - 4929 (2008/10/08)
A series of three geometrically constrained C2-symmetric Cu(I) mono-phenanthroline complexes were characterized by X-ray structural analysis, and their photophysical properties were investigated by absorption and emission spectroscopy. Visible light excitation yielded metal-to-ligand charge-transfer (MLCT) excited states with luminescence lifetimes up to 155 ns. Ultrafast ransient absorption spectroscopy provided further insights into the excited-state dynamics and suggests for all three complexes the formation of a phenanthroline radical anion. In agreement with electrochemical measurements, the data further indicate that coordinative rearrangements are involved in nonradiative deactivation 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 predominantly from 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 MLCT luminescence. The relationship between structural and photophysical data of the studied Cu(I) mono-phenanthroline complexes agrees well with current models describing the photophysics of the related Cu(I) bis-diimine complexes.
Dynamic NMR as a Nondestructive Method for the Determination of Rates of Dissociation. XV. Dissociation of Thioether and Ether hment from Ammonigands in Tin(IV) and Boron Complexes and Significance of Entropy of Activation Therein
Oki, Michinori,Yamada, Yasuhisa
, p. 1191 - 1194 (2007/10/02)
The rates of dissociation of thioether ligands which are imbedded in organotin(IV) compounds, such as trichlorostannane, were determined by the dynamic NMR method.The dynamic processes of the corresponding ether ligands was too fast to detect as the change in line shapes in 1H NMR spectra.All the boron compounds examined, which possessed similar structures to the stannane and were of the boronate type, failed to show dissociation of a thioether or ether ligand due to their large rates of dissociation.The rates of dissociation of a thioether-tribromoboron complex were determined by the same technique.The feature of the activation parameters was that the compounds examined exhibited fairly large positive entropy of activation in accordance with other results that involve dissociation of ionic species into covalent species.