Showing papers in "Chemical Physics in 1992"

TL;DR: In this paper, the aberrant nature of the thermal lens was taken into account and a theoretical model for the mode-mismatched, mode-matched dual-beam and single-beam methods was presented.

TL;DR: In this paper, 40 vibronic bands belonging to triplet-singlet transitions were detected between 620 and 700 nm and their vibronic structures were analyzed in terms of concurrent Herzberg-Teller and JahnTeller vibronic interactions.

TL;DR: In this paper, a critical assessment is made of the recently proposed momentum-averaged Gaussian-weighted (MAGW) method for incorporating angular (or momentum) resolution into quantum-mechanically calculated momentum distributions for comparison with EMS measurements, and the general efficacy of the proposed, semi-emperically based Gaussian angular (θ and ϕ) resolution functions as dimensioned in the MAGW method is tested by systematic application to high-level (essentially Hartree-Fock limit and/or configuration interaction) calculations of the momentum distributions of the outer

TL;DR: In this paper, it was found that orientational correlation functions are central for the analysis and understanding of the consequences of an incorrect treatment of long-range Coulomb forces in molecular dynamics simulations of solvated polypeptides.

TL;DR: In this paper, the authors investigated the method of calculation of solvation energies using the continuum solvent model and the semi-emperical NDDO quantum-chemical background, and the calculated solvation free energies of numerous organic ions agree with the experimental estimates within 2-3 kcal/mol.

TL;DR: In this paper, the authors present an approach for calculating the H 2 vibrational distribution, electron energy distribution function and negative ion concentration (H - ) based on the selfconsistent solution of the vibrational master equation and of the Boltzmann equation.

TL;DR: In this paper, high-resolution, rotationally resolved, laser-induced, fluorescence excitation spectra of the A1 and 6a10 bands of benzyl and the 000 band of p-methylbenzyl radicals were obtained in supersonic expansions.

TL;DR: In this paper, a variational approach for the determination of continuum orbitals, recently proposed in the one-dimensional case, is generalized to the multicenter molecular problem, and a test application is performed on the H2+ molecule in one-center approximation, with a radial basis or B-spline functions.

TL;DR: In this paper, the rotational/translational mode temperature has been measured by emission spectroscopy of rotationally resolved Swan bands of C 2 formed from reaction of the VV pumped CO.

TL;DR: In this article, the adsorption of isolated CO molecules on a perfect MgO(001) surface is investigated theoretically by the LCGTO-LDF cluster method.

TL;DR: In this article, the parent negative ion of polycyclic aromatic hydrocarbons (M) was found to form via as many as three negative ion states above 0.0 eV and with much larger cross sections than at 0.5 eV.

TL;DR: In this paper, a linear relationship was established between the polarizability differences of ground and excited state molecules (Δα) from electrochromism measurements and p MW, where p is the slope of the plot of absorption band maxima against the Lorenz-Lorentz function ϕ( n 2 ) = (n 2 − 2)/(n 2 + 2), n is the refractive index of the solvent and MW is the relative molecular weight of the solute.

TL;DR: In this article, the photophysical properties of rhodamines with non-alkylated amino groups (rhodamine 110 and 123) in water and in ethanol were investigated.

TL;DR: The threshold ionization energy of C 60 vacuum-deposited thin films was determined to be 6.17 ± 0.07 eV by ultraviolet photoemission spectroscopy with low photon-energy excitations and retarding-field analysis of photoemitted electrons as mentioned in this paper.

TL;DR: In this article, the absolute photoabsorption oscillator strength of silicon tetrafluoride has been measured using dipole (e, e) spectroscopy in the equivalent photon energy range 10-100 eV at an energy resolution of ≈ 1 eV fwhm.

TL;DR: In this article, the absorption spectra of chemically oxidized and reduced oligo(phenylenevinylene)s, 2,5-distyryl-thiophene, and poly(phenylphenyleneVylene) are reported and the essential conclusions are: (i) in all cases it is the radical ion that is the energetically favored species (ii) OPV forms divalent anions in the course of a second reduction step while PPPV forms cations and cations in the presence of an excess of reductant or oxidant

TL;DR: In this article, the transient IR spectra of vibrationally excited Rh(CO) 2 (acac) in dilute solutions of n -hexane and CCl 3 H were measured.

TL;DR: In this paper, the ab initio CASSCF method is applied in the case of the (NH3)5RupyzRu(NH 3)4+5/5+/6+ where pyz is pyrazine.

TL;DR: In this article, the authors studied the charge density wave structures of Brooker cations and their isoelectronic polyenes using ab initio SCF, AM1, and an empirical technique.

TL;DR: In this article, the photofragment imaging technique is used to measure the velocity distributions of the Br(2P 3 2 ) and Br* (2P 1 2 ) atoms formed following laser dissociation of CH3Br and CD3Br at 205 nm.

TL;DR: In this paper, the first fullerene epoxide has been studied using calorimetry and high resolution powder X-ray diffraction, showing that at room temperature, C 60 O is orientationally disordered with a face-centered cubic lattice, a = 14.185 A. Upon cooling an orientational ordering transition at 278 K leads to a low temperature simple cubic phase.

TL;DR: In this paper, the beryllium oxide has been studied at the ab initio periodic Hartree-Fock LCAO level using the CRYSTAL program.

TL;DR: In this article, both vibrationally and rotationally resolved spectra of the S, + So transition in jet-cooled triphenylamine (TPA) around 340320 nm are reported.

TL;DR: In this article, the authors used line positions available in the literature for vibrational-rotational and pure rotational transitions to determine accurate effective potential energy curves for the ground electronic states of 23 Na 19 F and 7 Li 127 I.

TL;DR: In this paper, Monte Carlo simulations have been carried out for systems including β-cyclodextrin (α- and β-CD) and water, using TIPS functions for nonbonded interactions of the CDs and the TIP3P model for water.

TL;DR: In this article, the electrogenerated chemiluminescence of intramolecular donor-acceptor compounds was studied in several organic solvents using the triple-step method.

TL;DR: In this article, the convergence of Green's entropy expansion for hard sphere systems of different dimensions (D = 1, 2, 3) was studied and the authors compared the two-body and three-body entropy contributions to the total excess entropy in these systems.

TL;DR: In this article, the resonance enhance (2+1) multiphoton ionization spectrum of I 2 has been recorded in the region 48000-75300 cm −1 using both linearly and circularly polarized light.

TL;DR: In this paper, the forbidden S1 <-- S0 transition of acetone has been investigated by laser-induced fluorescence measurements with a resolution of 270 MHz, and the rotational structure demonstrates that one deals with a-type transitions and there is a strong coupling between the torsional motion of the two CH3 groups and the tunneling, out-of-plane wagging motion (nu(23)) of the acetone.

TL;DR: In this paper, a number of singlet electronic states of pyrimidine are presented, including ground 1 A 1 and ground 1 B 2 states, and ten valence excited states.