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: 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.

The ν4 Vibration–Rotation Bands of C6H6 and C6D6: The Analysis of the Bands and the Determination of the Bond Lengths

1974 ◽  
Vol 52 (20) ◽  
pp. 1949-1955 ◽  
Author(s):  
A. Cabana ◽  
J. Bachand ◽  
J. Giguère
Keyword(s):  
High Resolution ◽  
Ground State ◽  
Spectroscopic Constants ◽  
Vibrational States ◽  
Rotational Constants ◽  
Bond Lengths ◽  
Vibration Rotation

The ν4. vibration–rotation bands of benzene and benzene-d6 have been recorded with high resolution. The K = 0 subbands have been analyzed and spectroscopic constants for both vibrational states have been calculated. Assuming D6h symmetry for the molecules the bond lengths have been determined from the ground state rotational constants of the two isotopic molecules. The values obtained are: r0(C—C) = 139.64 ± 0.02 pm and r0(C—H) = 108.31 ± 0.13 pm.

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.

scholarly journals Alternative method’s results for the non targeted determination of xenobiotics in food by means of high resolution and accuracy mass spectrometry

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Rossana Scarpone ◽  
Rachele Rocchi ◽  
Federico Bacà ◽  
Roberta Rosato ◽  
Francesco Chiumiento ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Data Processing ◽  
New Horizons ◽  
Wide Range ◽  
Accurate Mass Spectrometry ◽  
Food Matrices ◽  
Food Commodities ◽  
Near Future

AbstractThe application of a high resolution and accurate mass spectrometry (HRAMS) approach to detect xenobiotics in different food matrices by means of non targeted determination by UHPLC-Orbitrap followed by data processing analysis was described. Three case studies were reported to demonstrate the possibility to identify unexpected substances in different food commodities overcomes targeted method. This innovative approach could lay the foundation for its applicability to routine analysis in the near future giving the possibility to open new horizons to the research of a wide range of xenobiotics.

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.

High-Resolution Hydroxyl Radical Protein Footprinting: Biophysics Tool for Drug Discovery

2018 ◽  
Vol 47 (1) ◽  
pp. 315-333 ◽  
Author(s):  
Janna Kiselar ◽  
Mark R. Chance
Keyword(s):  
Protein Structure ◽  
High Resolution ◽  
Hydroxyl Radical ◽  
Solvent Accessibility ◽  
Side Chains ◽  
Protein Footprinting ◽  
Hydroxyl Radical Protein Footprinting ◽  
Wide Range ◽  
Hydroxyl Radical Footprinting

Hydroxyl radical footprinting (HRF) of proteins with mass spectrometry (MS) is a widespread approach for assessing protein structure. Hydroxyl radicals react with a wide variety of protein side chains, and the ease with which radicals can be generated (by radiolysis or photolysis) has made the approach popular with many laboratories. As some side chains are less reactive and thus cannot be probed, additional specific and nonspecific labeling reagents have been introduced to extend the approach. At the same time, advances in liquid chromatography and MS approaches permit an examination of the labeling of individual residues, transforming the approach to high resolution. Lastly, advances in understanding of the chemistry of the approach have led to the determination of absolute protein topologies from HRF data. Overall, the technology can provide precise and accurate measures of side-chain solvent accessibility in a wide range of interesting and useful contexts for the study of protein structure and dynamics in both academia and industry.

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