Showing papers in "Chemical Physics in 1973"

TL;DR: In this article, a general theoretical model for the IR spectra of the hydrogen bond was presented, which put on equal footing the Fermi resonance and the coupling between the high and low frequency modes.

TL;DR: In this paper, a new method for structure determination is compared to the usual Costain-Kraitchman substitution method, which contains less stringent conditions than the latter, permits a broad range of applications and provides a reliable molecular structure.

TL;DR: In this paper, the infrared spectrum of gaseous nitrogen has been examined at 77°K using a long path absorption cell and the spectrum shows a relatively strong diffuse band which can be assigned as collision-induced absorption.

TL;DR: In this article, the yields, lifetimes and spectra of singlet 1Au and triplet 3Au emissions from glyoxal vapor (0.003 to 10 torr) have been measured after initially pumping levels about 1000 cm−1 above the S1 zero-point level with the 4358 A Hg line and with flash excitation centered at 4345 A.

TL;DR: In this article, an electron-tunnelling model is used to describe the recombination of ions such as (naphthalene)+ with anions or solvated electrons in alkanes; theoretical difficulties and estimation of the barrier height are discussed.

TL;DR: In this article, the validity of the vibrational temperature concept, which may characterize the variaous distributions, is examined from different points of view, based on available data from chemiluminescence, chemical laser and molecular beams measurements and from classical trajectory calculations.

TL;DR: In this paper, the angular distributions of H and D atoms reactively scattered from the halogen molecules Cl 2, Br 2, l 2, ICl, IBr have been measured.

TL;DR: In this article, an extended double-zeta basis set has been used to obtain information about the energy spectrum of AlO. This has led to deduce the probable locations of as yet unobserved states and to predict the wavelength of a number of transitions in which they are involved.

TL;DR: The sites in which coronene, 1,12 benzoperylene or perylene are trapped in fast frozen n-paraffin matrices from n -hexane to n -nonane have been determined by careful examination and comparisons between their electronic spectra under especially well defined conditions of preparation and observation.

TL;DR: In this article, the microwave spectrum of thiocarbonyl fluoride, F 2 CS, has been investigated in the region 265-400 GHz Transitions of the 19 F 2 12 C 32 S and 19 F 3 12 C 34 S isotopic species have been observed and derived rotational constants yield the following ground stale structural parameters.

TL;DR: The effect of methyl substitution on the electronic properties of the benzyl radical has been studied by spectroscopic as well as theoretical methods as discussed by the authors, and the first and third excited doublet states of each radical were determined from the 0, 0 bands of their fluorescence (around 5000 A) and UV excitation (at about 3300 A) spectra.

TL;DR: In this article, a comparison between four methods for the analytic continuation of potential energy surfaces to their values corresponding to complex nuclear coordinates is presented, i.e., ab initio calculations in the complex plane, point method, moment method, and polynomial least squares fit.

TL;DR: In this paper, the phenomenological Bloch equations are solved for transient nutation in optical two-level systems, using the Feynman-Vernon-Hellwarth representation.

TL;DR: In this paper, a theory of vibronic structure is presented which includes the Born-Oppenheimer vibronic coupling and the Duschinsky and isotope dynamic mixing adiabatic corrections to the conventional Herzberg-Teller theory.

TL;DR: Scattering intensities as functions of angle and velocity, for the interaction of highly vibrationally excited potassium bromide with neon, argon, nitrogen, carbon dioxide, and carbon monoxide under molecular beam conditions, are reported.

TL;DR: In this article, the authors derived theoretical expressions for magnetic susceptibilities and ESR g values, along with the expression of Kurland and McGarvey, for dipolar and contact shifts, which were used to provide a consistent interpretation of the existing ESRg values and magnetometer susceptibilities as well as NMR and magnetic moments results.

TL;DR: In this paper, the contours of the υ 2 and υ 4 bands of carbon tetrachloride have been studied over the temperature range 240-373°K. Vibrational contributions to the spectral band shapes were estimated from the width of the totally symmetric υ 1 band and the presence of different isotopic CCl 4 molecules with different vibration frequencies was taken into account.

TL;DR: Stark effects on the optical absorption spectrum of the lowest singlet state in p -benzoquinone (PBQ)-h 4 and − d 4 single crystals at 18°K are reported in this article.

TL;DR: In this paper, the orientational anisotropy of the total collision cross section was measured using a beam of NO molecules in the 2 Π3/2-state at relative velocities between 450 and 700 m/sec.

TL;DR: In this article, a model is presented to decribe proton transfer between two sites of a hydrogen bond forming part of a larger molecular complex in a thermal environment, where the tunneling motion of the proton is assumed to couple strongly to the end atom vibration of the hydrogen bond via an interaction of the small polaron type.

TL;DR: In this paper, the authors measured the fluorescence spectra of the mixed crystal system naphthalene in perdeuteronaphthalenes at concentrations between 0.1 and 50% with high spectral resolution.

TL;DR: In this paper, the authors studied the intersystem crossing process for gaseous naphthalene and 1-methylnaphthylene excited at 265 nm by the fourth harmonic of a Nd glass laser, in collision-free conditions and in, the presence of inert gas (SF 6 ).

TL;DR: In this article, the relationship between the range characteristics of the optical potential and the dependence of the reaction probability upon the kinetic energy of the reactants is derived and other correlations are also presented.

TL;DR: The first three long-range dispersion coefficients C 6, C 8 and C 10 for all the pairs of atoms which arise from the iso-electronic sequences HeC 4+, BeC 2+ have been obtained by coupled time-dependent Hartree-Fock theory as discussed by the authors.

TL;DR: The electronic emission spectrum of benzaldehyde vapour excited in a discharge has been photographed under high resolution with a view to establishing which a″ vibrations are active in the a-X system as mentioned in this paper.

TL;DR: In this paper, the rotational contour of the 4683 A emission band of the o-xylyl radical was studied at high resolution using the rigid rotor approximation for various sets of values of the excited state rotational constants and directions of the transition moment.

TL;DR: In this article, a theoretical study suggests that, in general, proton magnetic shielding tensors are not axially symmetric when referred to an XH bond axis coordinate system.

TL;DR: In this article, it was shown that the solvent spectra shifts of 1 B b and 1 L a bands of aromatic polynuclear hydrocarbons in n -alkane solutions are different from those in branched alkane solutions.

TL;DR: Barriers of rotation and inversion, respectively, have been calculated for the species H 2 CNH (I), H 2 cNCH 3 (II), NHNH (III), NH ǫ nCH3 (IV) and their protonated species as mentioned in this paper.

TL;DR: In this article, the authors used the correlation function approach to investigate the distribution of the released electronic energy among the normal modes of the final ground state in naphthalene-h8.