Infrared emission spectroscopy and ab initio calculations on VCl

The emission spectrum of VCl has been investigated at high resolution in the 3000-19 400 cm⁻¹ region using a Fourier transform spectrometer. The bands were excited in a high temperature carbon tube furnace by the reaction of vanadium metal vapor and a trace of BCl₃ as well as in a microwave discharge lamp by the reaction of VOCl₃ vapor with active nitrogen. The spectra were recorded using the Fourier transform spectrometer associated with the McMath-Pierce telescope of the National Solar Observatory at Kitt Peak. The analysis of the system of VCl (previously labeled as ) has been extended by analyzing the rotational structure of some additional bands. A rotational analysis of the , , and subbands of the 0-2, 0-1, 0-0, and 1-0 bands, and the subband of the 0-1 and 0-0 bands has been obtained and molecular constants have been extracted. The subband was not identified in any of the assigned bands. The spectroscopic properties of the low-lying electronic states of VCl have been predicted by CASSCF/CMRCI ab initio calculations and the experimental assignments are supported by the ab initio results.     

The Rotational Analysis of the A(2)Pi(r)-X(2)Sigma(+) Band System of MgBr

The A(2)Pi(r)-X(2)Sigma(+) emission spectrum of the magnesium monobromide radical, MgBr, has been recorded with a Fourier transform spectrometer modified to record double-sided interferograms. The emission spectra of the Deltav = -2, -1, 0, +1 bands were generated in a microwave discharge of a mixture of argon and vaporized MgBr(2). The Deltav = 0 and -1 bands were rotationally resolved, but the F(2) spin component (A(2)Pi(3/2)) in the (1, 1), (1, 2) and vibrational bands with v' > 1 were missing in our spectra because of a strong predissociation in the A state. The molecular constants in both electronic states were determined for the two bromine isotopomers. The r(0) bond length in the A state is about 2.327 ?, which is about 0.02 ? shorter than in the ground state. Franck-Condon factors were calculated from the Rydberg-Klein-Rees potentials, and they reproduce the observed relative intensities of the bandheads. An upper limit for the dissociation energy (D(0)(0)) was obtained as 26 268.4 cm(-1), based on the absence of the energy level with v = 1, A(2)Pi(3/2), J = 1.5 in our spectrum. Copyright 2000 Academic Press.     

Laser excited fluorescence of CS2

Resonance fluorescence excited by ultraviolet lines of argon and krypton ion lasers has been observed from carbon disulfide. The strongest excitations are to single rotational levels within bands of Kleman's R system having K = 0 and 1. Fluorescence in each instance forms a long progression in the ground-state bending vibration, ν″₂. Vibrational levels as high as (1,28°,0) have been identified.     

Infrared emission spectroscopy of a new Σ-Σ system of TiCl

The spectra of TiCl have been reinvestigated in the 4200-8500 cm⁻¹ region using the 1-m Fourier transform spectrometer associated with the National Solar Observatory at Kitt Peak. The molecules were excited in a microwave discharge lamp operated with 3.0 Torr of He and a trace of TiCl₄ vapor, and the spectra were recorded at a resolution of 0.01 cm⁻¹. Three new bands with origins near 6938.9, 6900.2, and 6861.7 cm⁻¹ have been assigned as the 0-0, 1-1, and 2-2 bands of a new - transition. This assignment is supported by our recent ab initio calculations on TiCl and ZrCl [J. Chem. Phys. 114 (2001) 3977]. A rotational analysis of these bands has been carried out and spectroscopic constants have been extracted for the states.     

Fourier Transform Emission Spectroscopy of a New Φ-1Δ System of VO

High-resolution emission spectra of VO have been recorded in the region 3400-19 400 cm⁻¹ using a Fourier transform spectrometer. The molecules were observed from the reaction of VOCl₃ with active nitrogen. Two new bands, with origins near 5539.46 and 5551.69 cm⁻¹, are assigned as the 0-0 bands of the ²Φ_5/2-²Δ_3/2 and ²Φ_7/2-²Δ_5/2 spin-orbit components (respectively) of a ²Φ-1²Δ electronic transition of VO. A rotational analysis of both subbands has been carried out and spectroscopic constants have been extracted. The 1²Δ state is known from the previous analysis of the near infrared doublet transitions of VO and the new ²Φ excited state has rotational constants very similar to those of another ²Φ state observed previously [Merer et al., J. Mol. Spectrosc.125, 465 (1987)].     

Attitudes and preferences: Approaches to representing decision maker desires

Informative interrelationships between attitudes and preferences when formally studying a conflict within the framework of the Graph Model for Conflict Resolution are specified through the development of formal theorems. Specifically, the parallel nature of attitudes and preferences is illuminated to show how attitudes can provide a simple way to more effectively represent complex preference structures when decision makers hold concern for other decision makers’ interests. To illustrate this important property of attitudes, the Graph Model for Conflict Resolution is applied to the negotiation over the sale of a brownfield property both with and without attitudes.     

Ground state potential energy curve and dissociation energy of MgH

New high-resolution visible emission spectra of the MgH molecule have been recorded with high signal-to-noise ratios using a Fourier transform spectrometer. Many bands of the A 2Pi-->X 2Sigma+ and B' 2Sigma+-->X 2Sigma+ electronic transitions of 24MgH were analyzed; the new data span the v' = 0-3 levels of the A 2Pi and B'2Sigma+ excited states and the v'=0-11 levels of the X 2Sigma+ ground electronic state. The vibration-rotation energy levels of the perturbed A 2Pi and B' 2Sigma+ states were fitted as individual term values, while those of the X 2Sigma+ ground state were fitted using the direct-potential-fit approach. A new analytic potential energy function that imposes the theoretically correct attractive potential at long-range, and a radial Hamiltonian that includes the spin-rotation interaction were employed, and a significantly improved value for the ground state dissociation energy of MgH was obtained. The v'=11 level of the X 2Sigma+ ground electronic state was found to be the highest bound vibrational level of 24MgH, lying only about 13 cm(-1) below the dissociation asymptote. The equilibrium dissociation energy for the X 2Sigma+ ground state of 24MgH has been determined to be De=11104.7+/-0.5 cm(-1) (1.37681+/-0.00006 eV), whereas the zero-point energy (v'=0) is 739.11+/-0.01 cm(-1). The zero-point dissociation energy is therefore D0=10365.6+/-0.5 cm(-1) (1.28517+/-0.00006 eV). The uncertainty in the new experimental dissociation energy of MgH is more than 2 orders of magnitude smaller than that for the best value available in the literature. MgH is now the only hydride molecule other than H2 itself for which all bound vibrational levels of the ground electronic state are observed experimentally and for which the dissociation energy is determined with subwavenumber accuracy.