HIGH-RESOLUTION RAMAN SPECTROSCOPY OF GASES: XVII. THE PURE ROTATIONAL RAMAN SPECTRUM OF IODOACETYLENE

1963 ◽  
Vol 41 (12) ◽  
pp. 2098-2101 ◽  
Author(s):  
W. Jeremy Jones ◽  
B. P. Stoicheff ◽  
J. K. Tyler
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectrum ◽  
High Resolution ◽  
Bond Length ◽  
Ground State ◽  
Rotational Constant ◽  
Bond Lengths ◽  
A Value

A study of the pure rotational Raman spectrum of iodoacetylene has yielded a value of 0.10622 cm−1 for the ground-state rotational constant. From this value, and from assumed C≡C and C—H bond lengths of 1.203 Å and 1.055 Å respectively, the C—I bond length is calculated to be 1.988 Å.

HIGH RESOLUTION RAMAN SPECTROSCOPY OF GASES: X. ROTATIONAL SPECTRUM OF BUTATRIENE (H2C=C=C=CH2)

1957 ◽  
Vol 35 (8) ◽  
pp. 837-841 ◽  
Author(s):  
B. P. Stoicheff
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectrum ◽  
High Resolution ◽  
Rotational Constant ◽  
Rotational Spectrum ◽  
A Value

The rotational Raman spectrum of butatriene (H2C=C=C=CH2) at a pressure of 2 cm. Hg was photographed with a 21 ft. grating spectrograph. An analysis of this spectrum (based on the symmetric top approximation) yields the rotational constant [Formula: see text](B0 + C0) = 0.13141 ± 0.0001 cm−1. If the two outer C=C bonds in butatriene are assumed to have the same length as the C=C bonds in allene,namely 1.309 Å, it is found that the central C=C bond has a length of 1.284 ± 0.006 Å, a value which is shorter than that of the C=C bonds in ethylene and in allene.

HIGH RESOLUTION RAMAN SPECTROSCOPY OF GASES: IV. ROTATIONAL RAMAN SPECTRUM OF CYANOGEN

1954 ◽  
Vol 32 (10) ◽  
pp. 635-638 ◽  
Author(s):  
C. K. Møller ◽  
B. P. Stoicheff
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectrum ◽  
High Resolution ◽  
Bond Length ◽  
Second Order ◽  
Single Bond ◽  
Rotational Constants ◽  
A Value ◽  
Symmetric Molecule ◽  
Concave Grating

The rotational Raman spectrum of cyanogen gas at [Formula: see text] atm. pressure has been photographed in the second order of a 21 ft. concave grating spectrograph. The simplicity of the spectrum and the observed intensity alternation of the lines show that C2N2 is a linear symmetric molecule. An analysis of the spectrum yields for the rotational constants[Formula: see text]By assuming a value for the C≡N bond length of 1.157 Å, the length of the C—C single bond was calculated to be 1.380 Å.

HIGH RESOLUTION RAMAN SPECTROSCOPY OF GASES: VI. ROTATIONAL SPECTRUM OF SYMMETRIC BENZENE-d3

1956 ◽  
Vol 34 (4) ◽  
pp. 350-353 ◽  
Author(s):  
A. Langseth ◽  
B. P. Stoicheff
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectrum ◽  
High Resolution ◽  
Rotational Constant ◽  
Benzene Molecule ◽  
Second Order ◽  
Rotational Spectrum ◽  
Internuclear Distances

The pure rotational Raman spectrum of C6H3D3 vapor at a pressure of 15 cm. Hg was photographed in the second order of a 21 ft. grating. The value of the rotational constant was found to be B0 = 0.17165 ± 0.0001 cm−1. This result confirms the earlier spectroscopic values of the internuclear distances in the benzene molecule.

High-resolution Raman spectroscopy of gases and the determination of molecular bond lengths

2000 ◽  
Vol 78 (5-6) ◽  
pp. 327-390 ◽  
Author(s):  
W J Jones
Keyword(s):  
Raman Spectroscopy ◽  
High Resolution ◽  
Bond Length ◽  
Subsequent Development ◽  
Bond Lengths ◽  
Pure Rotation ◽  
Wide Range ◽  
Laser Sources ◽  
Vibration Rotation

This review highlights the developments that have taken place in the field of high-resolution Raman spectroscopy of gases from the pioneering studies of Stoicheff and Welsh in the early fifties to the present day. This period has seen major changes in the methods that have been employed for investigating pure rotation and vibration-rotation spectra from these initial studies with Hg excitation through to the deployment of laser sources for incoherent Raman scattering at enhanced sensitivity, and the subsequent development of the techniques of nonlinear Raman spectroscopy at resolutions of ~10-3 cm-1. A central theme in this review is the measurement of accurate rotational constants for nonpolar molecules that have then been employed for the determination of molecular geometries and bond lengths. The studies by Stoicheff of the pure rotational spectra of a wide range of linear and symmetric-top molecules provided an extensive data base that served to supplement bond-length determinations from other methods and enabled him to correlate CC and CH bond length variations in noncyclic compounds with changes in their environment. The discovery of laser sources in the sixties provided exciting new opportunities for the examination of pure rotation and vibration-rotation spectra at enhanced resolution and sensitivity and broadened dramatically the scope of the field. Apart from the improvements in the incoherent scattering methods afforded by these new sources, the discovery of a range of new nonlinear Raman phenomena, a field in which Stoicheff made equally important contributions, led to the creation of a range of new coherent nonlinear Raman methods that have been widely employed for the study of all rotor classes. Representative examples of the many investigations performed with the various spectroscopic methods over this period are given, together with the results of the structure determinations achieved from the analyses of the rotational spectra.PACS Nos.: 33.20Fb, 36.20.Hb

HIGH RESOLUTION RAMAN SPECTROSCOPY OF GASES: XIII. ROTATIONAL SPECTRA AND STRUCTURES OF THE ZINC-, CADMIUM-, AND MERCURY-DIMETHYL MOLECULES

1960 ◽  
Vol 38 (11) ◽  
pp. 1516-1525 ◽  
Author(s):  
K. Suryanarayana Rao ◽  
B. P. Stoicheff ◽  
R. Turner
Keyword(s):  
Raman Spectroscopy ◽  
High Resolution ◽  
Rotational Constants ◽  
Carbon Bond ◽  
Rotational Spectra ◽  
Bond Lengths ◽  
Zinc Cadmium ◽  
Symmetric Top Molecules

The pure rotational spectra of gaseous Zn(CH3)2, Cd(CH3)2, Hg(CH3)2, and of the fully deuterated molecules have been photographed with a 21-ft grating. The spectra are typical of symmetric top molecules and consist of many evenly spaced rotational lines having a separation of about 0.45 cm−1. An analysis of the spectra yielded the rotational constants (in cm−1)[Formula: see text]From these constants the following metal—carbon bond lengths were determined: Zn—C = 1.929 Å, Cd—C = 2.112 Å, and Hg—C = 2.094 Å. Relations for the C—H bond lengths and HCH angles were also obtained.

HIGH RESOLUTION RAMAN SPECTROSCOPY OF GASES: III. RAMAN SPECTRUM OF NITROGEN

1954 ◽  
Vol 32 (10) ◽  
pp. 630-634 ◽  
Author(s):  
B. P. Stoicheff
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectrum ◽  
High Resolution ◽  
Electronic Spectra ◽  
Second Order ◽  
Published Data ◽  
Rotational Spectrum ◽  
Rotational Constants ◽  
Vibrational Constants

The pure rotational spectrum and the Q branch of the 1–0 band of N2 were photographed in the second order of a 21 ft. grating. An analysis of the rotational spectrum yields the rotational constants[Formula: see text]The value of B0 together with the Bν values obtained from the electronic bands of N2 gives[Formula: see text]Revised values of the vibrational constants have also been calculated using the results of the present work and the published data on the electronic spectra.

HIGH RESOLUTION RAMAN SPECTROSCOPY OF GASES: XV. ROTATIONAL SPECTRUM AND MOLECULAR STRUCTURE OF CYCLOBUTANE

1962 ◽  
Vol 40 (6) ◽  
pp. 725-731 ◽  
Author(s):  
R. C. Lord ◽  
B. P. Stoicheff
Keyword(s):  
Molecular Structure ◽  
Raman Spectroscopy ◽  
High Resolution ◽  
Bond Length ◽  
Raman Spectra ◽  
Point Group ◽  
Rotational Spectrum ◽  
Rotational Constants ◽  
Group D

An investigation of the rotational Raman spectra of normal and fully deuterated cyclobutane (C4H8 and C4D8) has given values of the rotational constants for these molecules. From these results it was found that the C—C bond length is 1.558 ± 0.003 Å, irrespective of whether cyclobutane belongs to the molecular point group D4h (planar C4 ring) or D2d (puckered C4 ring).

Vibration-rotation bands of monodeuteroacetylene and the molecular dimensions

1956 ◽  
Vol 234 (1198) ◽  
pp. 306-317 ◽  
Keyword(s):  
High Resolution ◽  
Ground State ◽  
Fermi Resonance ◽  
Rotational Constants ◽  
Bond Lengths ◽  
Vibrational Levels ◽  
Vibration Rotation ◽  
Molecular Dimensions

Some vibration-rotation bands of monodeuteroacetylene have been measured with high resolution. Values have been derived for the coefficients α i relating the rotational constants in different vibrational levels, as follows: α 2 = + 0⋅00439, α 3 = + 0⋅00638, α 4 = — 0⋅0032 2 , α 5 = — 0⋅0011. Using the value B 00000 = 0⋅9910 5 cm -1 , also determined from many bands, a new value, B e = 0⋅9948, has been obtained leading to new estimates for the bond lengths r e CH = 1⋅058 Å, and r e C≡C = 1⋅205 0 . The l -doubling coefficient has been determined in two states, namely, q 00010 = 0⋅0056 and q 00003 = 0⋅0072. In the ground state the results are in accordance with a centrifugal stretching coefficient D = 0⋅7 x 10 -6 , but in some higher levels a markedly different value is derived, which may, however, arise through the effects of Fermi resonance.

Vibration-rotation bands of methyl fluoride

1954 ◽  
Vol 222 (1151) ◽  
pp. 443-455 ◽  
Keyword(s):  
Ground State ◽  
Rotational Constant ◽  
Microwave Spectrum ◽  
Complete Analysis ◽  
Methyl Fluoride ◽  
A Value ◽  
Infra Red ◽  
Type Band ◽  
Vibration Rotation

The vibration-rotation bands of methyl fluoride between 2⋅5 and 5 μ have been measured with higher resolution than previously. Three parallel bands have been analyzed, providing three independent values for B ", the rotational constant in the ground state. Each of these values is close to that obtained from the microwave spectrum (0⋅8518 cm -1 ), and some earlier values deduced from infra-red bands are shown to be incorrect. A value of 2⋅28 x 10 -6 cm -1 has also been obtained for D J , the centrifugal stretching constant, which is shown to be more satisfactory than that previously deduced from the microwave spectrum. A perpendicular type band has been resolved fairly completely, and it has been possible to measure the P and R lines of the sub-bands in addition to the strong Q branches. An analysis has been made which accounts satisfactorily for most of the lines in the entire band, and this provides the first example of such a complete analysis of a perpendicular band of a symmetrical top molecule.

HIGH RESOLUTION RAMAN SPECTROSCOPY OF GASES: IX. SPECTRA OF H2, HD, AND D2

1957 ◽  
Vol 35 (6) ◽  
pp. 730-741 ◽  
Author(s):  
B. P. Stoicheff
Keyword(s):  
Raman Spectroscopy ◽  
High Resolution ◽  
Power Series ◽  
Infrared Spectra ◽  
Ground State ◽  
Power Series Expansion ◽  
Experimental Accuracy ◽  
Vibrational Bands ◽  
Complete Set ◽  
Electronic Ground

The pure rotational lines and the Q branch lines of the 1–0 vibrational bands of H2, HD, and D2 have been photographed with a 21 ft. grating spectrograph. From these spectra, a complete set of constants for the ν = 0 and 1 levels of all three molecules have been determined. When these constants are combined with Herzberg's results of the forbidden infrared spectra of H2 and HD they lead to improved values of the electronic ground state constants of H2 and HD. The leading terms in the Dunham power series expansion of the potential are calculated for H2 and HD and are found to be mutually consistent. The isotopic relations are obeyed within experimental accuracy, and the small constants De, Be, and He, are in agreement with values given by theoretical formulae.

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