K N Upadhya

Study of indium monochloride molecule

Abstract The spectrum of the indium monochloride molecule has been recorded in emission using different sources of excitation (dc hollow cathode, microwave, radio-frequency and transformer discharges) with or without an inert gas (helium or argon) under low as well as high dispersions. A large number of hitherto unobserved bands involving higher vibrational levels of the known A, B, A, C and X states have been recorded. The formation of head has been marked in some positive sequences of the A-X and B-X systems. The earlier reported analyses for the A-X, B-X, C-X and A-X systems have been refined. In addition to these known systems, two groups of weak bands forming two new systems along with the continua could be observed. A tentative vibrational analysis of these bands is also proposed.

On the C1Π−X1Σ+ system of the indium monochloride molecule and its dissociation energy

Abstract The emission spectrum of the C-X system of the InCl molecule was photographed in the third order of a 10.6m concave grating spectrograph at a reciprocal dispersion of 0.22 A mm-1 and a resolution ∼ 0.005 A. The (0, 0) and (0, 1) bands were resolved and the rotational analyses of these bands have been carried out. Precise rotational constants were calculated from direct least square fitting to the measured line positions of each band. The Λ-doubling constant in the C1Π state is found to be negligible (105 cm-1). Rotational predissociation has been observed at J = 73 in the ν=0 level of the C state for the first time. The upper limit of the dissociation energy is found to be ∼37565 cm-1. Franck-Condon factors and r-centroids of the bands and potential energy curves of the combining states were determined.

The B-A system of CP molecule

The B-A system of CP molecule has been reinvestigated. The rotational structures in the (0, 0) and (1, 1) bands have been photographed in the second order of a 10.6 m grating with 25µ slit width. The molecular constants have been determined using a weighted least squares fit computer program. It is found that the spin-splitting constant in the B-state is negative and not positive as reported by previous workers. An accurate value ofα in the A-state could be determined. The present analysis also suggests that the spin-splitting constant in the ground state of CP should be positive, hence the assignment of theR1 andR2 orP1 andP2 branches in the B-X system of CP by Barwaldet al should be interchanged.

Analysis of some bands of the ? system of PO

The rotational analysis of some bands of the beta band system of the PO molecule has been revised and some new bands, for example (1,2), (3,2), (3,4), (4,3), (4,5) and (7,8) of the subsystem B2 Sigma +-x2 Pi 3/2 and (4,3), (5,4), (5,5) and (6,7) of the subsystem B2 Sigma +-x2 Pi 1/2 have been analysed. Perturbation in the 6th and 7th vibrational levels of the upper excited state have been investigated.

Rotational structure of the 3050-3250 Angstrom system of the BiF molecule

A rotational analysis of the (0, 0), (0, 1) and (1, 0) bands of the 3050-3250 Angstrom system of the BiF molecule has been made and the nature of the electronic state involved in this transition discussed.

Rotational analysis of the B-X system of antimony monoxide molecule

The rotational structure in the 2 Sigma +-2 Pi 3/2 subsystem and the B-X system of the SbO molecule, photographed earlier under high resolution, has been reanalysed. It is concluded that all earlier reported rotational analyses are incorrect and the B2 Sigma + state has an appreciable spin splitting. New molecular constants for the two combining states are presented.

The A-X system of the SbO+ molecule

The spectrum of the SbO+ molecule has been studied under high resolution for the first time. Analysis of the rotational structure in (1,2) and (1,3) bands leads to the following rotational constants: B1=0.325 13 cm-1, D1=2.09*10-7 cm1; B2=0.359 64 cm-1, B3=0.357 41 cm-1, Be=0.365 13 cm-1, ae=0.002 23 cm-1, D2=1.57*10-7 cm-1, D3=1.47*10-7 cm-1, re=1.8074 AA; nu (1,2)=23 568.12 cm-1, nu (1,3)=22657.79 cm-1.

Rotational analysis of the C2 Δ 5/2-X2 Π 5/2 and G2 Δ 5/2-X2 Π 3/2 systems of the SnF molecule

The rotational analysis of the (0,0)3/2 sub-band of the C-X and G-X systems of the SnF molecule has been carried out. The rotational constants determined for Sn120F and Sn118F from the analysis are reported.

Fine structure in the B-X system of SiCl

Rotational structure in five bands, viz (0,0)1/2, (0,1)1/2, (0,1)3/2, (1,0)3/2 and (0,2)3/2 of the B-X system of the silicon monochloride molecule has been analysed by photographing the spectra in the third order of a 10.6 m concave grating spectrograph (dispersion 0.22 A/mm). The rotational constants of the states participating in the transition are obtained as follows: Be=0.2791+or-0.0003 cm-1; De=1.8*10-7 cm-1; alpha e=0.0020 cm-1; Be=0.2561+or-0.0001 cm-1; De=2.30*10-7 cm-1; alpha e=0.0015 cm-1; lambda -type doubling in the 2 Pi 1/2 component=0.006 cm-1. The spin splitting in the excited state is found to be of negligible magnitude. The weak isotopic lines due to 37Cl have also been detected.

A new band system in the red region of CuBr

A new band system of CuBr involving two new electronic states has been observed in the spectral region 5900-6300 AA. This is the first observation of a transition involving two excited states in any diatomic copper halide. The transition appears to be Delta Lambda =0 type. The vibrational assignments of the bands have been confirmed by measuring the isotopes shifts. The vibrational constants for the two states for 63Cu79Br are omega e=300.35 cm-1, omega e=241.52 cm-1, omega exe=0.42 cm-1, omega exe=1.46 cm-1 and nu e=16267.55 cm-1. A partial rotational analysis of the (0,0) band has also been carried out.