Duncan A. Wild

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The ultrafast internal conversion (IC) dynamics of aldehyde-substituted apocarotenoids (n'-apo-beta-caroten-n'-als with n=4, 8 and 12) have been investigated in a systematic variation of conjugation length and solvent polarity using time-resolved femtosecond transient absorption spectroscopy. After excitation to the S2 state with different excess energies,(More)
The ultrafast internal conversion dynamics of 12'-apo-beta-carotenoic-12'-acid (12'CA), 10'-apo-beta-carotenoic-10'-acid (10'CA) and 8'-apo-beta-carotenoic-8'-acid (8'CA) have been investigated by femtosecond pump-probe spectroscopy. The three apocarotenoic acids were excited to the S(2) state with different excess energies. Time constants tau(1) for the IC(More)
The ultrafast internal conversion (IC) dynamics of the carbonyl carotenoid 12'-apo-beta-caroten-12'-al has been investigated in solvents of varying polarity using time-resolved femtosecond transient absorption spectroscopy. The molecules were excited to the S(2) state by a pump beam of either 390 or 470 nm. The subsequent intramolecular dynamics were(More)
Infrared spectra of mass-selected F- -(CH4)n (n = 1-8) clusters are recorded in the CH stretching region (2500-3100 cm-1). Spectra for the n = 1-3 clusters are interpreted with the aid of ab initio calculations at the MP2/6-311++G(2df 2p) level, which suggest that the CH4 ligands bind to F- by equivalent, linear hydrogen bonds. Anharmonic frequencies for(More)
Anion clusters formed between a chloride or bromide anion and H2S molecules have been investigated using ab initio methods. Cluster structures, binding energies, and vibrational properties were predicted at the MP2 level with basis sets of aug-cc-pvtz and aug-cc-pvdz quality. Vibrational self consistent field (VSCF) calculations were employed to correct the(More)
Anion photoelectron spectra are reported for the iodide-carbon monoxide clusters, with supporting ab initio calculations for the 1:1 dimer anion and neutral complexes. A C(s) minimum geometry is predicted for the anion complex, while for the neutral complex two linear van der Waals minima are predicted differing in the attachment point of the iodine, that(More)
Infrared vibrational predissociation spectra are recorded for Br(-)-(NH(3))(n) (n = 1-4) and I(-)-NH(3) clusters in the N-H stretch region (3040-3460 cm(-1)). To aid spectral assignments and clarify structures of the Br(-)-(NH(3))(n) clusters, ab initio calculations are performed at the MP2/aug-cc-pVDZ and MP2/aug-cc-pVTZ levels of theory. The Br(-)-NH(3)(More)
A previously reported complex, [Ni(C(21)H(21)O(3)P)(3)] or Ni[P(O-o-tolyl(3))(3)] [Gosser & Tolman (1970). Inorg. Chem. 9, 2350-2353], crystallized in the monoclinic space group C2/c, and its solid-state structure was determined. The Ni(0) atom adopts an essentially trigonal-planar geometry as a consequence of the steric congestion of the ligands. Three of(More)
For the CH3CHOO Criegee intermediates (ethanal-oxide) and analogous anions, we obtain heats of formations and electron affinities at CCSDT(Q)/CBS level of theory by means of the high-level W3-F12 thermochemical protocol. The electron affinities amount to 0.20 eV and 0.35 eV for the cis and trans isomer, respectively. Neutral cis and trans isomers are(More)
Infrared spectra of mass-selected Cl- -C2H4 and Br- -C2H4 complexes are recorded in the vicinity of the ethylene CH stretching vibrations (2700-3300 cm(-1) using vibrational predissociation spectroscopy. Spectra of both complexes exhibit 6 prominent peaks in the CH stretch region. Comparison with calculated frequencies reveal that the 4 higher frequency(More)