Timothy S Zwier

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Single-conformation spectroscopy of the three lignin monomers (hereafter "monolignols") p-coumaryl alcohol (pCoumA), coniferyl alcohol (ConA), and sinapyl alcohol (SinA) has been carried out on the isolated molecules cooled in a supersonic expansion. Laser-induced fluorescence excitation, dispersed fluorescence, resonant two-photon ionization, UV-UV(More)
The photochemistry of diacetylene (C4H2), the largest hydrocarbon to be unambiguously identified in planetary atmospheres, is of considerable importance to understanding the mechanisms by which complex molecules are formed in the solar system. In this work, the primary products of C4H2's ultraviolet photochemistry were determined in a two-laser pump-probe(More)
Ultraviolet spectroscopy of the G- and S-type lignin subunits, guaiacol (G) and syringol (S), along with their para-methylated derivatives 4-methylguaiacol (4-MG) and 4-methylsyringol (4-MS), has been carried out in the cold, isolated environment of a supersonic jet. The excitation spectra and dispersed fluorescence (DFL) spectra of G and 4-MG show strong(More)
Ultraviolet spectroscopy of sinapoyl malate, an essential UV-B screening agent in plants, was carried out in the cold, isolated environment of a supersonic expansion to explore its intrinsic UV spectral properties in detail. Despite these conditions, sinapoyl malate displays anomalous spectral broadening extending well over 1000 cm(-1) in the UV-B region,(More)
Issues and Scientific Advances Bruce C. Garrett,*,† David A. Dixon,*,‡ Donald M. Camaioni,† Daniel M. Chipman,§ Mark A. Johnson,# Charles D. Jonah,⊥ Gregory A. Kimmel,† John H. Miller,| Thomas N. Rescigno,X Peter J. Rossky,3 Sotiris S. Xantheas,† Steven D. Colson,† Allan H. Laufer,[ Douglas Ray,† Paul F. Barbara,3 David M. Bartels,§ Kurt H. Becker,∆ Kit H.(More)
The single-conformation spectroscopy of two model γ-peptides has been studied under jet-cooled conditions in the gas phase. The methyl-capped triamides, Ac-γ(2)-hPhe-γ(2)-hAla-NHMe and Ac-γ(2)-hAla-γ(2)-hPhe-NHMe, were probed by resonant two-photon ionization (R2PI) and resonant ion-dip infrared (RIDIR) spectroscopies. Four conformers of(More)
Resonant ion-dip infrared spectroscopy has been employed to record cluster-size-specific spectra of C6H6–~CH3OH!m with m51–6 in the OH stretch fundamental region. The comparison of the spectra with the results of ab initio calculations on the pure methanol clusters enables the assignment of the hydrogen-bonding architecture in the clusters. In all cases,(More)
Neutral serotonin-(H(2)O)(n) clusters with n = 1,2 have been studied under jet-cooled conditions using a combination of resonant two-photon ionization (R2PI), UV-UV hole-burning (UVHB), and resonant ion-dip infrared (RIDIR) spectroscopy. Serotonin (5-hydroxytryptamine, SERO) is a close analogue of tryptamine, differing by the addition of an OH substituent(More)
[2.2.2]Paracylcophane (tricyclophane, TCP) is a macrocycle with three phenyl substituents linked by ethyl bridges (-CH2CH2-) in the para-position, forming an aromatic-rich pocket capable of binding various substituents, including nature's solvent, water. Building on previous work [Buchanan, E. G.; et al. J. Chem. Phys. 2013, 138, 064308] that reported on(More)