The vibrational spectrum of the N-methylpentadeuteropyridinium ion

1967 ◽  
Vol 20 (9) ◽  
pp. 1805 ◽  
Author(s):  
E Spinner
Keyword(s):  
Raman Spectrum ◽  
Vibrational Spectrum ◽  
Vibrational Spectra ◽  
Plane Bending

A comparison of the vibrational spectra of the N-methylpyridinium and N-methylpentadeuteropyridinium ions has shown that ring deuteration modifies the pattern of the ?substituent-sensitive? bands in the Raman spectrum considerably. This is expected if N-CMe stretching mixes largely with an aromatic CH in-plane bending rather than with purely skeletal vibrations. The effective symmetry of the ion is lower than C2v.

Calcium Carbodiimide Compounds Revisited – Syntheses, Single Crystal Structure Determination and Vibrational Spectra of Ca11N6[CN2]2, Ca4N2[CN2] and Ca[CN2]

2008 ◽  
Vol 63 (5) ◽  
pp. 530-536 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo
Keyword(s):  
Crystal Structure ◽  
Raman Spectrum ◽  
Single Crystal ◽  
Single Crystals ◽  
Vibrational Spectra ◽  
Structure Determination ◽  
X Ray ◽  
Characteristic Features ◽  
Reported Data ◽  
Correct Data

Single crystals of Ca11N6[CN2]2 (dark red needles, tetragonal, P42/mnm (no. 136), a = 1456.22(5), and c = 361.86(2) pm, Z = 2), Ca4N2[CN2] (transparent yellow needles, orthorhombic, Pnma (no. 62), a = 1146.51(11), b = 358.33(4), and c = 1385.77(13) pm, Z = 4) and Ca[CN2] (transparent, colorless, triangular plates, rhombohedral, R3̅m (no. 166), a = 369.00(3), and c = 1477.5(3) pm, Z = 3) were obtained by the reaction of Na2[CN2], CaCl2 and Ca3N2 (if demanded by stoichiometry) in arc-welded Ta ampoules at temperatures between 1200 - 1400 K. Their crystal structures were re-determined by means of single crystal X-ray structure analyses. Additionally, the Raman spectra were recorded on these same single crystals, whereas the IR spectra were obtained with the KBr pellet technique. The title compounds exhibit characteristic features for carbodiimide units with D∞h symmetry (d(C-N) = 121.7 - 123.8 pm and ∡ (N-C-N) = 180°). The vibrational frequencies of these units are in the expected range (Ca11N6[CN2]2: νs = 1230, νs = 2008; δ = 673/645/624 cm−1; Ca4N2[CN2]: νs = 1230, νs = 1986; δ = 672/647 cm−1; Ca[CN2]: νs = 1274, νs = 2031, δ = 668 cm−1). The structural results are more precise than the previously reported data, and with the newly attained Raman spectrum of Ca11N6[CN2]2 we correct data reported earlier.

Studies of the Jahn - Teller effect IV. The vibrational spectra of spin-degenerate molecules

1962 ◽  
Vol 255 (1050) ◽  
pp. 31-53 ◽  
Keyword(s):  
Raman Spectrum ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Physical Theory ◽  
Vibronic Coupling ◽  
Infra Red ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Active Vibration ◽  
Degenerate States

The physical theory necessary for interpreting the vibrational spectra of spin-degenerate molecules is developed in this paper. Particular attention is paid to those molecules whose behaviour is expected to be markedly different from that of both orbitally non-degenerate molecules and those with purely spatial degeneracy. These include certain Kramers degenerate molecules, whose Raman spectra are expected to contain reverse-polarized contributions, and also tetrahedral and octahedral molecules in fourfold degenerate states. The case of a fourfold degenerate octahedral molecule is investigated in the limits of strong vibronic coupling by one of the Jahn—Teller active vibrations (e g and t 2g ). It turns out that the forbidden t 2u vibration may be infra-red active, that the Raman spectrum may contain reverse-polarized contributions and that both infra-red and Raman spectra may contain strong progressions of bands involving multiple excitations of the vibronically active vibration.

Borinine (Borabenzene): Its Structure and Vibrational Spectrum. A Quantumchemical Study

1987 ◽  
Vol 42 (4) ◽  
pp. 352-360 ◽  
Author(s):  
Gerhard Raabe ◽  
Wolfgang Schleker ◽  
Eberhard Heyne ◽  
Jörg Fleischhauer
Keyword(s):  
Electronic Structure ◽  
Vibrational Spectrum ◽  
Ab Initio ◽  
Vibrational Spectra ◽  
Photoelectron Spectrum ◽  
High Reactivity ◽  
Basis Sets ◽  
Rare Gas ◽  
Ab Initio Theory ◽  
Semiempirical Mndo

Recently we reported the results of some semiempirical and ab initio studies in which we compared the electronic structure of the hitherto unknown borinine with those of benzene and pyridine. The results of our calculations led us to the conclusion that the elusive nature of borabenzene is caused by its high reactivity, which might at least in part be due to the pronounced σ acceptor properties of a low-lying σ* molecular orbital.We now present the results of further ab initio and semiempirical (MNDO) investigations in which we performed full geometry optimizations for the molecule using two different basis sets (STO-3G, 4-31G) and also calculated the vibrational spectra of the 10B and 11B isotopomeric borabenzene molecules at the 4-31 G level of ab initio theory and with the semiempirical MNDO method.The calculated vibrational spectrum might be helpful to the experimentalist in identifying the molecule, for example trapped in a rare gas matrix among the side products.The calculated orbital energies can be useful in identifying the molecule by means of its photoelectron spectrum.

scholarly journals Darstellung und Charakterisierung von Tetrabutylammonium-Tetraiodooxotechnetat(V), (TBA) [TcOI4] / Preparation and Characterization of Tetrabutylammonium Tetraiodooxotechnetate(V), (TBA)[TcOI4]

1981 ◽  
Vol 36 (2) ◽  
pp. 138-140 ◽  
Author(s):  
G. Peters ◽  
W. Preetz
Keyword(s):  
Raman Spectrum ◽  
Exchange Reaction ◽  
Vibrational Spectra ◽  
Ligand Exchange ◽  
Resonance Raman ◽  
The Other ◽  
Resonance Raman Spectrum ◽  
Ligand Exchange Reaction ◽  
Complex Ion

Abstract Pure (TBA)[TcOI4] is prepared from (TBA)[TcOCl4] by ligand exchange reaction with Nal in acetone. The vibrational spectra indicate C4v symmetry for the complex ion. On excitation with the 514.5 nm line of an Ar-laser a resonance Raman spectrum is obtained showing v(TcO) = 996 cm-1 and four of its overtones, symmetrically surrounded by groups of bands arising as well from the sums as from the differences of frequencies with the other fundamentals. In contrast to the ligand exchange reaction the reduction of Tc04- with conc. HI yields products always contaminated with polyiodides. The extremely strong Raman scatterer (TBA)l3 is detected by a characteristic doublet at 111 and 116 cm-1 and even small amounts of it cover the Raman spectrum of (TBA)[TcOI4].

A reinvestigation of the vibrational spectrum of SeO2F− and the preparation and raman spectrum of SeO2F22−

1976 ◽  
Vol 7 (1-3) ◽  
pp. 43-54 ◽  
Author(s):  
Ronald James Gillespie ◽  
Paul Spekkens ◽  
John Buchanan Milne ◽  
Duncan Moffett
Keyword(s):  
Raman Spectrum ◽  
Vibrational Spectrum

THE VIBRATIONAL SPECTRA OF SULPHURYL AND THIONYL HALIDES

1961 ◽  
Vol 39 (11) ◽  
pp. 2171-2178 ◽  
Author(s):  
R. J. Gillespie ◽  
E. A. Robinson
Keyword(s):  
Raman Spectrum ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Normal Modes ◽  
Infrared And Raman Spectra ◽  
Fundamental Frequencies

New assignments are proposed for the fundamental frequencies of SOF2, SOCl2, SO2Cl2, SO2F2, and SO2FBr, based on new measurements of the Raman spectrum of SO2Cl2 and previous measurements of the infrared and Raman spectra of these molecules. The fundamental frequencies of these molecules are found to be related to each other and to those of similar molecules when the normal modes are described in terms of characteristic vibrations of the SO, SO2, S(Hal), and S(Hal)2 groups.

Schwingungsspektrum und Kristallstruktur des fünffach-koordinierten cis-Dioxo-dipicolinato-vanadat(V)-Anions / Vibrational Spectrum and Crystal Structure of the cis-Dioxo-dipicolinato-vanadium(V) Anion

1978 ◽  
Vol 33 (3) ◽  
pp. 265-267 ◽  
Author(s):  
Bernhard Nuber ◽  
Johannes Weiss ◽  
Karl Wieghardt
Keyword(s):  
Crystal Structure ◽  
Raman Spectrum ◽  
Vibrational Spectrum ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Distorted Trigonal Bipyramid ◽  
Ir And Raman

Abstract cis-Dioxo-dipicolinato-vanadate(V), Crystal Structure, IR, Raman The crystal structure of Cs[V(O)2(dipic)]·H2O (dipic = pyridine-2,6-dicarboxylate) has been determined by single crystal x-ray diffraction analysis. The compound crystallizes in the monoclinic space group P21/a, with cell constants a =737.8(3), 6=1917.5(5), c = 792.9(3) pm, β= 94.87(6)°, and Z = 4. The geometry about vanadium is a distorted trigonal bipyramid containing a cis-dioxo moiety (∢ O-V-O 109.9(3)°, V=O bond lengths 161.0(6) and 161.5(6) pm). Vibrational absorptions νs(V - 0) and νas(V=O) were found at 956 and 947 cm-1 in the IR and Raman spectrum, resp.

Fragment quantum chemical approach to geometry optimization and vibrational spectrum calculation of proteins

2016 ◽  
Vol 18 (3) ◽  
pp. 1864-1875 ◽  
Author(s):  
Jinfeng Liu ◽  
John Z. H. Zhang ◽  
Xiao He
Keyword(s):  
Vibrational Spectrum ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Quantum Chemical ◽  
Geometry Optimization ◽  
Infrared And Raman Spectra ◽  
Chemical Approach ◽  
Spectrum Calculation ◽  
Quantum Chemical Approach ◽  
Molecular Fractionation

Geometry optimization and vibrational spectra (infrared and Raman spectra) calculations of proteins are carried out by a quantum chemical approach using the EE-GMFCC (electrostatically embedded generalized molecular fractionation with conjugate caps) method (J. Phys. Chem. A, 2013, 117, 7149).

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