DFT and MP2 Study of the Molecular Structure and Vibrational Spectra of the Anticancer Agent Cyclophosphamide

2012 ◽  
Vol 67 (12) ◽  
pp. 1305-1313 ◽  
Author(s):  
Hassan M. Badawi ◽  
Wolfgang Förner
Keyword(s):  
Molecular Structure ◽  
Vibrational Spectra ◽  
Anticancer Agent ◽  
Normal Modes ◽  
Anomeric Effect ◽  
Infrared And Raman Spectra ◽  
Normal Coordinate ◽  
X Ray ◽  
Axial Structure ◽  
The One

The possible conformations in the most stable structure of cyclophosphamide were investigated at the DFT-B3LYP and MP2/6-311G** levels of calculation. The axial structure is calculated to be lower in energy than the equatorial form of cyclophosphamide by 5 (MP2) to 6 (DFT) kcal mol-1 because of a very weak anomeric effect and weak conjugation. Further it is the same structure as the one found in the X-ray investigations both of the hydrate and of the anhydrous form. The computed DFT vibrational frequencies of the axial structure were used to analyze the infrared and Raman spectra using normal-coordinate calculations to provide reliable assignments to the normal modes of the molecule.

scholarly journals Röntgenstrukturanalyse und Schwingungsspektren von Trischwefeldistickstoffdioxid, S3N2O2 [1] / X-ray Structural Analysis and Vibrational Spectra of Trisulfurdinitrogendioxide, S3N2O2 [1]

1980 ◽  
Vol 35 (7) ◽  
pp. 792-796 ◽  
Author(s):  
Ralf Steudel ◽  
Jürgen Steidel ◽  
Norbert Rautenberg
Keyword(s):  
Molecular Structure ◽  
Structural Analysis ◽  
Raman Spectra ◽  
Conformational Changes ◽  
Vibrational Spectra ◽  
Crystal And Molecular Structure ◽  
Infrared And Raman Spectra ◽  
Molecular Symmetry ◽  
Torsion Angles ◽  
X Ray

A redetermination of the crystal and molecular structure of the chain-like molecule S(NSO)2 resulted in the following molecular parameters: d(SO) = 146.5(2), d(S = N) = 153.4(2), d(S-N) = 165.7(2) pm, bond angles OSN = 117.5(1)°, SNS = 123.6(2)°, and NSN = 97.2(1)°, torsion angles OSNS = -0.3(2)°, and SNSN = -177.7(2)° (molecular symmetry C2). Infrared and Raman spectra of S(NSO)2 are reported and assigned; there is no evidence for conformational changes on dissolution of crystalline S(NSO)2

Vibrational spectra of aquadioxotetra; peroxodivanadates(V) M2[V2O2(O2)4(H2O)]·xH2O (M = N(CH3)4, Cs)

1990 ◽  
Vol 55 (6) ◽  
pp. 1485-1490 ◽  
Author(s):  
Peter Schwendt ◽  
Milan Sýkora
Keyword(s):  
Raman Spectra ◽  
Vibrational Spectra ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Infrared And Raman Spectra ◽  
Empirical Correlations ◽  
Normal Coordinate ◽  
Bond Lengths ◽  
Stretching Vibrations

The infrared and Raman spectra of M2[V2O2(O2)4(H2O)]·xH2O and M2[V2O2(O2)4(D2O)]·xD2O (M = N(CH3)4, Cs) were measured. In the region of the vanadium-oxygen stretching vibrations, the spectra were interpreted based on normal coordinate analysis, employing empirical correlations between the bond lengths and force constants.

Synthesis, crystal and molecular structure, and vibrational spectra of the complex (COOH)2•2H2O•18-crown-6

1986 ◽  
Vol 64 (1) ◽  
pp. 142-147 ◽  
Author(s):  
Suzanne Deguire ◽  
François Brisse ◽  
Jacques Ouellet ◽  
Rodrigue Savoie
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Oxalic Acid ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Crystal And Molecular Structure ◽  
Unit Cell ◽  
Infrared And Raman Spectra ◽  
O 18 ◽  
Stoichiometric Complex

A stoichiometric complex of formula (COOH)2•2H2O•18-crown-6 has been obtained from oxalic acid and the macrocyclic polyether 18-crown-6. The crystals of the complex have a monoclinic unit cell and belong to the P21/c space group. The components in the adduct are linked through hydrogen bonds in a polymer-like fashion: -crown–H2O–HOOCCOOH–OH2–crown–, where the oxalic acid molecules are present in two distinct disordered orientations. The infrared and Raman spectra of the complex are also reported and interpreted.

The Vibrational Spectrum and Urey-Bradley Force Constants of the Trifluoromethyltrifluoroborate(1-) Anion

1973 ◽  
Vol 27 (3) ◽  
pp. 209-213 ◽  
Author(s):  
John F. Jackovitz ◽  
Charles E. Falletta ◽  
James C. Carter
Keyword(s):  
Potential Energy ◽  
Vibrational Spectrum ◽  
Energy Distribution ◽  
Force Field ◽  
Raman Spectra ◽  
Normal Modes ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
Infrared And Raman Spectra ◽  
Normal Coordinate

Infrared and Raman spectra for (K+) (CF3BF3−) have been obtained from 4000 to 50 cm−1. Spectral assignments were made on the basis of C3v symmetry using both 10B and 11B compounds. In addition, a normal coordinate analysis was performed to obtain the potential energy distribution of the normal modes. A Urey-Bradley type force field was used, and force constants obtained for the CF3 and BF3 groupings were compared to those in C2F6 and BF4−.

Normal Coordinate Analysis of Benitoite (BaTiSi3O9) and its Constituent Ring

1992 ◽  
Vol 291 ◽  
Author(s):  
Charles C. Kim ◽  
M. I. Bell ◽  
D. A. McKeown
Keyword(s):  
Crystal Structure ◽  
Raman Spectra ◽  
Infrared Spectra ◽  
Normal Modes ◽  
Infrared And Raman Spectra ◽  
Normal Coordinate ◽  
Structure Space ◽  
New Information ◽  
Atomic Interactions ◽  
Modes Of Vibration

ABSTRACTThe normal modes of vibration and their frequencies are calculated for benitoite, a mineral whose crystal structure (space group D23h) consists of three-membered silicate rings (Si3O9) linked by Ba+2 and Ti+4 ions. The calculation unambiguously assigns the normal modes to the lines in the Raman and infrared spectra and determines the atomic interactions. On the assumption that mode mixings and splittings due to inter-ring interactions are small, the normal frequencies of the isolated ring of C3h, symmetry are determined. The identification of normal modes characteristic of three-membered silicate rings may prove to be a valuable guide in the interpretation of the infrared and Raman spectra of amorphous silicates, potentially leading to new information on the ring statistics of these materials.

scholarly journals Darstellung, Kristallstruktur und Schwingungsspektren von cyclo-Undekaschwefel (S11) und von cyclo-Tridekaschwefel (S13) / Preparation, Crystal Structure, and Vibrational Spectra of cyclo-Undecasulfur (S11) and of cyclo-Tridecasulfur (S13)

1986 ◽  
Vol 41 (8) ◽  
pp. 958-970 ◽  
Author(s):  
Ralf Steudel ◽  
Jürgen Steidel ◽  
Torsten Sandow
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Infrared And Raman Spectra ◽  
X Ray ◽  
Bond Angles ◽  
Torsional Angles

AbstractThe homocyclic S11 and S13 molecules have been synthesized from titanocenepentasulfide and S6Cl2 or S8Cl2, respectively, and obtained as yellow crystals which are metastable for several days at 20 °C. X-Ray structural analyses of single crystals at -105± 5 °C exhibited molecules of approximately C2 symmetry with bond distances (d), bond angles (a) and torsional angles (r) in the following ranges: S11 : d = 203.2 -211.0 pm, α = 103.3-108.6°, τ = 69.3 - 140.5°; S13: d = 197.8 - 211.3 pm, α = 102.8-111.1°, τ = 29.5 - 116.3°. Infrared and Raman spectra of S11 and S13 are reported. In addition, the synthesis of S6Cl2 and S8Cl2 from S6 or S8, respectively, and chlorine is described.

Vibrational Spectra of Triphenyl Compounds of Group VA Elements

1969 ◽  
Vol 23 (1) ◽  
pp. 12-16 ◽  
Author(s):  
Kosuke Shobatake ◽  
Clarence Postmus ◽  
John R. Ferraro ◽  
Kazuo Nakomoto
Keyword(s):  
Raman Spectra ◽  
Vibrational Spectra ◽  
Phenyl Group ◽  
Normal Coordinate Analysis ◽  
Infrared And Raman Spectra ◽  
Normal Coordinate ◽  
Bending Vibrations ◽  
Depolarization Ratios

The infrared and Raman spectra of triphenyl compounds of Group VA elements PPh3, AsPh3, SbPh3, and BiPh3 (Ph represents the phenyl group), have been reported in the 530–100 cm−1 region. The metal-phenyl stretching and bending vibrations have been assigned with the aid of approximate normal coordinate analysis and depolarization ratios of Raman lines.

The Vibrational Spectra and Crystal Structure of Acenaphthylene

1973 ◽  
Vol 51 (3) ◽  
pp. 402-404 ◽  
Author(s):  
A. Bree ◽  
R. A. Kydd ◽  
V. V. B. Vilkos ◽  
R. S. Williams
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Room Temperature ◽  
Infrared And Raman Spectra ◽  
Depolarization Ratio ◽  
X Ray

A study of the polarized infrared and Raman spectra of acenaphthylene single crystals has been made. These results, together with Gordon and Yang's preliminary X-ray work, suggest that the molecules pack in some disordered arrangement in the solid at room temperature. Most of the A1 fundamentals were identified in the Raman solution spectrum from their low depolarization ratio, and a few tentative assignments of nontotally symmetric fundamentals were made.

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