Energy Dispersive XAFS: Characterization of Electronically Excited States of Copper(I) Complexes

Energy dispersive X-ray absorption spectroscopy (ED-XAS), in which the whole XAS spectrum is acquired simultaneously, has been applied to reduce the real-time for acquisition of spectra of photoinduced excited states by using a germanium microstrip detector gated around one X-ray bunch of the ESRF (100 ps). Cu K-edge XAS was used to investigate the MLCT states of [Cu(dmp)(2)](+) (dmp =2,9-dimethyl-1,10-phenanthroline) and [Cu(dbtmp)(2)](+) (dbtmp =2,9-di-n-butyl-3,4,7,8-tetramethyl-1,10-phenanthroline) with the excited states created by excitation at 450 nm (10 Hz). The decay of the longer lived complex with bulky ligands, was monitored for up to 100 ns. DFT calculations of the longer lived MLCT excited state of [Cu(dbp)(2)](+) (dbp =2,9-di-n-butyl-1,10-phenanthroline) with the builder amine ligands, indicated that the excited state behaves as a Jahn-Teller distorted Cu(H) site, with the interligand dihedral angle changing from 83 to 60 degrees as the tetrahedral coordination geometry flattens and a reduction in the Cu-N distance of 0.03 angstrom.     «

Energy dispersive X-ray absorption spectroscopy (ED-XAS), in which the whole XAS spectrum is acquired simultaneously, has been applied to reduce the real-time for acquisition of spectra of photoinduced excited states by using a germanium microstrip detector gated around one X-ray bunch of the ESRF (100 ps). Cu K-edge XAS was used to investigate the MLCT states of [Cu(dmp)(2)](+) (dmp =2,9-dimethyl-1,10-phenanthroline) and [Cu(dbtmp)(2)](+) (dbtmp =2,9-di-n-butyl-3,4,7,8-tetramethyl-1,10-phenanth...     »

ISI Document Delivery No.: 171FQ Times Cited: 0 Cited Reference Count: 41 Tromp, Moniek Dent, Andrew J. Headspith, Jon Easun, Timothy L. Sun, Xue-Zhong George, Michael W. Mathon, Olivier Smolentsev, Grigory Hamilton, Michelle L. Evans, John Epsrc [ep/i01974x/1, ep/e060404/1]; esrf [ch2849]; snf [200021_135226] We thank EPSRC for funding (EP/I01974X/1) and access to the RCaHfacilities. The ESRF is gratefully acknowledged for beamtime under project CH2849. M.T. gratefully acknowledges the EPSRC (EP/E060404/1) and G.S. funding from SNF (Grant No. 200021_135226). The following people are gratefully acknowledged for their help and discussions before, during and/or after the experiment: Sofia Diaz-Moreno, Monica Amboage, Matthew Gerring, Janet Groves, Christine Mills, Florian Perrin, Marie Christine Dominguez, Sakura Pascarelli, Friederike Ewald, and Michael Wulff. 0 Amer chemical soc Washington     «

ISI Document Delivery No.: 171FQ Times Cited: 0 Cited Reference Count: 41 Tromp, Moniek Dent, Andrew J. Headspith, Jon Easun, Timothy L. Sun, Xue-Zhong George, Michael W. Mathon, Olivier Smolentsev, Grigory Hamilton, Michelle L. Evans, John Epsrc [ep/i01974x/1, ep/e060404/1]; esrf [ch2849]; snf [200021_135226] We thank EPSRC for funding (EP/I01974X/1) and access to the RCaHfacilities. The ESRF is gratefully acknowledged for beamtime under project CH2849. M.T. gratefully acknowledges the EPSRC...     »