Shedding light on the structure of a photoinduced transient excimer by time-resolved diffraction.
Time-resolved single-crystal diffraction performed with synchrotron radiation shows that the 53(1) micros phosphorescent state, generated in the crystalline phase of trimeric {[3,5-(CF3)(2)Pyrazolate]Cu}(3) molecules by exposure to 355 nm of light at 17 K, is due to the formation of an excimer rather than the shortening of the intramolecular Cu...Cu distances within the trimeric units, or the formation of a continuous chain of interacting molecules. One of the intermolecular Cu...Cu distances contracts by 0.56 Angstroms from 4.018(1) to 3.46(1) Angstroms;, whereas the interplanar spacing of the trimers is reduced by 0.65 Angstroms; from 3.952(1) to 3.33(1) Angstroms. Density-functional theory calculations support the formation of a Cu...Cu bond through the intermetallic transfer of a Cu 3d electron to a molecular orbital with a large 4p contribution on the reacting Cu atoms.
Vorontsov
Ivan I
II
Department of Chemistry, SUNY at Buffalo, New York 14260-3000, USA.
Kovalevsky
Andrey Yu
AY
Chen
Yu-Sheng
YS
Graber
Tim
T
Gembicky
Milan
M
Novozhilova
Irina V
IV
Omary
Mohammad A
MA
Coppens
Philip
P