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Title: Restricted Photochemistry in the Molecular Solid State: Structural Changes on Photoexcitation of Cu(I) Phenanthroline Metal-to-Ligand Charge Transfer (MLCT) Complexes by Time-Resolved Diffraction

Abstract

The excited-state structure of Cu{sup I}[(1,10-phenanthroline-N,N') bis(triphenylphosphine)] cations in their crystalline [BF{sub 4}] salt has been determined at both 180 and 90 K by single-pulse time-resolved synchrotron experiments with the modified polychromatic Laue method. The two independent molecules in the crystal show distortions on MLCT excitation that differ in magnitude and direction, a difference attributed to a pronounced difference in the molecular environment of the two complexes. As the excited states differ, the decay of the emission is biexponential with two strongly different lifetimes, the longer lifetime, assigned to the more restricted molecule, becoming more prevalent as the temperature increases. Standard deviations in the current Laue study are very much lower than those achieved in a previous monochromatic study of a Cu(I) 2,9-dimethylphenanthroline substituted complex (J. Am. Chem. Soc. 2009, 131, 6566), but the magnitudes of the shifts on excitation are similar, indicating that lattice restrictions dominate over the steric effect of the methyl substitution. Above all, the study illustrates emphatically that molecules in solids have physical properties different from those of isolated molecules and that their properties depend on the specific molecular environment. This conclusion is relevant for the understanding of the properties of molecular solid-state devices, which aremore » increasingly used in current technology.« less

Authors:
; ; ; ; ; ; ; ; ; ;  [1]
  1. UC
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
National Science Foundation (NSF)
OSTI Identifier:
1038611
Resource Type:
Journal Article
Journal Name:
J. Phys. Chem. A
Additional Journal Information:
Journal Volume: 116; Journal Issue: (13) ; 04, 2012; Journal ID: ISSN 1089-5639
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Makal, Anna, Benedict, Jason, Trzop, Elzbieta, Sokolow, Jesse, Fournier, Bertrand, Chen, Yang, Kalinowski, Jaros, #322, aw, A., Graber, Tim, Henning, Robert, Coppens, Philip, and Buffalo). Restricted Photochemistry in the Molecular Solid State: Structural Changes on Photoexcitation of Cu(I) Phenanthroline Metal-to-Ligand Charge Transfer (MLCT) Complexes by Time-Resolved Diffraction. United States: N. p., 2015. Web. doi:10.1021/jp300313s.
Makal, Anna, Benedict, Jason, Trzop, Elzbieta, Sokolow, Jesse, Fournier, Bertrand, Chen, Yang, Kalinowski, Jaros, #322, aw, A., Graber, Tim, Henning, Robert, Coppens, Philip, & Buffalo). Restricted Photochemistry in the Molecular Solid State: Structural Changes on Photoexcitation of Cu(I) Phenanthroline Metal-to-Ligand Charge Transfer (MLCT) Complexes by Time-Resolved Diffraction. United States. https://doi.org/10.1021/jp300313s
Makal, Anna, Benedict, Jason, Trzop, Elzbieta, Sokolow, Jesse, Fournier, Bertrand, Chen, Yang, Kalinowski, Jaros, #322, aw, A., Graber, Tim, Henning, Robert, Coppens, Philip, and Buffalo). 2015. "Restricted Photochemistry in the Molecular Solid State: Structural Changes on Photoexcitation of Cu(I) Phenanthroline Metal-to-Ligand Charge Transfer (MLCT) Complexes by Time-Resolved Diffraction". United States. https://doi.org/10.1021/jp300313s.
@article{osti_1038611,
title = {Restricted Photochemistry in the Molecular Solid State: Structural Changes on Photoexcitation of Cu(I) Phenanthroline Metal-to-Ligand Charge Transfer (MLCT) Complexes by Time-Resolved Diffraction},
author = {Makal, Anna and Benedict, Jason and Trzop, Elzbieta and Sokolow, Jesse and Fournier, Bertrand and Chen, Yang and Kalinowski, Jaros and #322 and aw, A. and Graber, Tim and Henning, Robert and Coppens, Philip and Buffalo)},
abstractNote = {The excited-state structure of Cu{sup I}[(1,10-phenanthroline-N,N') bis(triphenylphosphine)] cations in their crystalline [BF{sub 4}] salt has been determined at both 180 and 90 K by single-pulse time-resolved synchrotron experiments with the modified polychromatic Laue method. The two independent molecules in the crystal show distortions on MLCT excitation that differ in magnitude and direction, a difference attributed to a pronounced difference in the molecular environment of the two complexes. As the excited states differ, the decay of the emission is biexponential with two strongly different lifetimes, the longer lifetime, assigned to the more restricted molecule, becoming more prevalent as the temperature increases. Standard deviations in the current Laue study are very much lower than those achieved in a previous monochromatic study of a Cu(I) 2,9-dimethylphenanthroline substituted complex (J. Am. Chem. Soc. 2009, 131, 6566), but the magnitudes of the shifts on excitation are similar, indicating that lattice restrictions dominate over the steric effect of the methyl substitution. Above all, the study illustrates emphatically that molecules in solids have physical properties different from those of isolated molecules and that their properties depend on the specific molecular environment. This conclusion is relevant for the understanding of the properties of molecular solid-state devices, which are increasingly used in current technology.},
doi = {10.1021/jp300313s},
url = {https://www.osti.gov/biblio/1038611}, journal = {J. Phys. Chem. A},
issn = {1089-5639},
number = (13) ; 04, 2012,
volume = 116,
place = {United States},
year = {Thu Oct 15 00:00:00 EDT 2015},
month = {Thu Oct 15 00:00:00 EDT 2015}
}