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Title: Method for direct deconvolution of heat signals in transient adsorption calorimetry

Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Surface Science
Additional Journal Information:
Journal Volume: 633; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-07-03 09:25:44; Journal ID: ISSN 0039-6028
Country of Publication:

Citation Formats

Wolcott, Christopher A., and Campbell, Charles T. Method for direct deconvolution of heat signals in transient adsorption calorimetry. Netherlands: N. p., 2015. Web. doi:10.1016/j.susc.2014.11.005.
Wolcott, Christopher A., & Campbell, Charles T. Method for direct deconvolution of heat signals in transient adsorption calorimetry. Netherlands. doi:10.1016/j.susc.2014.11.005.
Wolcott, Christopher A., and Campbell, Charles T. 2015. "Method for direct deconvolution of heat signals in transient adsorption calorimetry". Netherlands. doi:10.1016/j.susc.2014.11.005.
title = {Method for direct deconvolution of heat signals in transient adsorption calorimetry},
author = {Wolcott, Christopher A. and Campbell, Charles T.},
abstractNote = {},
doi = {10.1016/j.susc.2014.11.005},
journal = {Surface Science},
number = C,
volume = 633,
place = {Netherlands},
year = 2015,
month = 3

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.susc.2014.11.005

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  • Full multiple scattering (FMS) Minuit XANES (MXAN) has been combined with laser pump-probe K-edge X-ray absorption spectroscopy (XAS) to determine the structure of photoexcited Ni(II)tetramesitylporphyrin, Ni(II)TMP, in dilute toluene solution. It is shown that an excellent simulation of the XANES spectrum is obtained, excluding the lowest-energy bound-state transitions. In ground-state Ni(II)TMP, the first-shell and second-shell distances are, respectively, d(Ni-N) = (1.93 {+-} 0.02) {angstrom} and d(Ni-C) = (2.94 {+-} 0.03) {angstrom}, in agreement with a previous EXAFS result. The time-resolved XANES difference spectrum was obtained from the spectra of Ni(II)TMP in its photoexcited T{sub 1} state and its ground state,more » S{sub 0}. The XANES difference spectrum has been analyzed to obtain both the structure and the fraction of the T{sub 1} state. If the T{sub 1} fraction is kept fixed at the value (0.37 {+-} 0.10) determined by optical transient spectroscopy, a 0.07 {angstrom} elongation of the Ni-N and Ni-C distances [d(Ni-N) and d(Ni-C)] is found, in agreement with the EXAFS result. However, an evaluation of both the distance elongation and the T{sub 1} fraction can also be obtained using XANES data only. According to experimental evidence, and MXAN simulations, the T{sub 1} fraction is (0.60 {+-} 0.15) with d(Ni-N) = (1.98 {+-} 0.03) {angstrom} (0.05 {angstrom} elongation). The overall uncertainty of these results depends on the statistical correlation between the distances and T{sub 1} fraction, and the chemical shift of the ionization energy because of subtle changes of metal charge between the T{sub 1} and S{sub 0} states. The T{sub 1} excited-state structure results, independently obtained without the excited-state fraction from optical transient spectroscopy, are still in agreement with previous EXAFS investigations. Thus, full multiple scattering theory applied through the MXAN formalism can be used to provide structural information, not only on the ground-state molecules but also on very short-lived excited states through differential analysis applied to transient photoexcited species from time-resolved experiments.« less
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