Browsing by Author "K.N. Upadhya"

Now showing 1 - 20 of 27

A high resolution investigation of the near ultraviolet absorption spectrum of p-fluorochlorobenzene
(1969) S.N. Thakur; K.N. Upadhya
The intense b ands in the near ultraviolet absorption spectrum of p-fluoro-chlorobenzene show regular rotational features under high resolution. Band contour analysis confirms the electronic transition to be 1B2 ← 1A1. The rotational lines have been interpreted by a prolate symmetric rotor model for the molecule. The observed rotational constants indicate that the size of the phenyl ring increases on electronic excitation. © 1969.
A new band system in the red region of CuBr
(1981) R. Tripathi; S.B. Rai; K.N. Upadhya
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 e'xe'=0.42 cm-1, omega e"xe"=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.
Analysis of some bands of the β system of PO
(1972) S.B. Rai; D.K. Rai; K.N. Upadhya
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 +-x 2 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.
E-X band system of the copper iodide molecule [8]
(1966) K.P.R. Nair; K.N. Upadhya
[No abstract available]
Electronic spectra of parafluorobromobenzene
(Springer India, 1980) Shashi K. Singh; K.N. Upadhya
The electronic absorption spectrum of parafluorobromobenzene is reported together with its band shape and molecular geometry. The electronic transition is found to be the 2900-2400 Å system and the analysis consistent with other paraheterohalogenated benzenes. The intense bands, including 0-0, are double headed and are B-type in nature. A-type vibronic bands are also observed although less intense than the B-type bands. In all 9 excited states and 5 ground state fundamentals could be assigned. © 1980 Indian Academy of Sciences.
Electronic transition-moment variation in the B1 - X1Σ+ system of PbO and determination of the effective vibrational temperature
(1970) Prem Shankar Dube; K.N. Upadhya; D.K. Rai
The B1 - X1Σ+ (4200-5000 Å) system of PbO was excited in a vertical copper arc. Relative intensities of the bands were measured by using the photographic technique. The data were interpreted through appropriate use of Franck-Condon factors (qv′v″) and r-centroids (rv′v″). It was found that the electronic transition moment varies as Re(r) = const. (1-0.5408r) for 2.02 ≤ r ≤ 2.148. A straight line plot of log ∑ υ″logIυ′υ″em V4 against G′(v′) for v′ = 0, 1, 2, 3, 4, was made and the effective vibrational temperature has been calculated from the slope of this line to be 2240°K. © 1970.
Fine structure in the B-X system of SiCl
(1974) S.B. Rai; J. Singh; K.N. Upadhya; D.K. Rai
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.
On the C1Π-X1Σ+ system of the indium monochloride molecule and its dissociation energy
(1986) K. Perumalsamy; S.B. Rai; K.N. Upadhya
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 Å mm-1 and a resolution ∼ 0.005 Å. 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. © 1986.
Rotation Structure In The Ultraviolet Bands Of Snf
(1976) Ram Sagar Ram; K.N. Upadhya; D.K. Rai
Rotation structure of (0,0) bands of the (C-X)3/2and (G-X)3/2systems of SnF molecule has been photographed in the third order of a 10.6 meter concave grating spectrograph. The rotation constants, as determined from the analysis, have been reported to be. © 1976, Taylor & Francis Group, LLC. All rights reserved.
Rotational analysis of the B-X system of antimony monoxide molecule
(1982) R. Tripathi; K.N. Upadhya; R.B. Singh; S.B. Rai
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.
Rotational analysis of the C2 Δ 5/2-X 2 Π 5/2 and G2 Δ 5/2-X 2 Π 3/2 systems of the SnF molecule
(1973) R.S. Ram; K.N. Upadhya; D.K. Rai
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.
Rotational analysis of the D-X band system of the SbO molecule
(1970) B. Rai; K.N. Upadhya; D.K. Rai
The rotational analysis of two bands 1-1 and 1-2 of the D-X system of the SbO molecule has been performed. The transition has been identified as 2 Π 1/2-2 Π 1/2.
Rotational structure of the 2250 Angstrom system of the BiF molecule
(1969) A.K. Chaudhry; K.N. Upadhya; D.K. Rai
The rotational analysis of the (0,0), (0,1) and (0,3) bands of the 2250 Angstrom system of the BiF molecule has been carried out and the molecular constants determined. The transition is found to be of the 1II- 3Σ- type.
Rotational structure of the 2650-2850 Angstrom system of the BiF molecule
(1968) B.S. Mohanty; D.K. Rai; K.N. Upadhya; N.L. Singh
The rotational structure of the (0, 0) and (0, 1) bands of the 2650-2850 Angstrom system of the BiF molecule has been photographed in emission in the third order of a 35 ft concave grating spectrograph (dispersion, 0.22 Angstrom mm-1) and their rotational analysis carried out. The nature of the upper and lower states of this system has been discussed.
Rotational structure of the 3050-3250 Angstrom system of the BiF molecule [4]
(1968) A.K. Chaudhry; K.N. Upadhya; D.K. Rai; B.S. Mohanty
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.
Structure and Analysis of Some Bands of the B—»X and D—»X Systems of PbO
(1973) R.S. Ram; Jagadish Singh; K.N. Upadhya
The (1,0) and (1,1) bands of the B-X and (0,1) and (0,2) bands of the D-X systems have been photographed in the second and third orders, respectively, of a 10.6 meter concave grating spectrograph and the rotational structures of these bands have been analysed. The rotational constants for the most abundant 2QQ 16 isotopic molecule Pb 0 are derived as follows s In addition, several perturbations observed in the vT= 1 level of the B state and v’ =0 level of the D state have been studied. With the help of the Schmid and G-ero relation and from the appearance of the perturbed structure, it has been concluded. © 1973 by Marcel Dekker, Inc. All Rights Reserved.
Structure and analysis of some bands of the β-system of PO molecule
(1968) B.S. Mohanty; D.K. Rai; K.N. Upadhya
Rotational analysis of (4-4), (7-6), (7-8) bands of the2Σ-2II1/2 sub-system and (3-3) band of2Σ-2II3/2 sub-system of the β-system of PO have been made. Vibrational assignments of fifteen new bands of this system have also been reported. © 1968 Indian Academy of Sciences.
Study of indium monochloride molecule
(1985) K. Perumalsamy; S.B. Rai; K.N. Upadhya; D.K. Rai
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. © 1985.
The A-X and the B-X systems of the CuBr molecule
(1981) G.P. Mishra; R. Tripathi; S.B. Rai; K.N. Upadhya; D.K. Rai
[No abstract available]
The A-X system of the SbO+ molecule
(1981) R. Tripathi; S.B. Rai; K.N. Upadhya
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: B'1=0.325 13 cm-1, D'1=2.09*10-7 cm1; B"2=0.359 64 cm-1, B"3=0.357 41 cm-1, B"e=0.365 13 cm-1, a"e=0.002 23 cm-1, D"2=1. 57*10-7 cm-1, D"3=1.47*10 -7 cm-1, r"e=1.8074 AA; nu (1,2)=23 568.12 cm-1, nu (1,3)=22657.79 cm -1.