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Journal ArticleDOI

Infrared and Raman spectra and normal co-ordinate analysis of dimethyl sulfoxide and dimethyl sulfoxide-d6

TL;DR: In this paper, a complete assignment of the C2SO skeleton was made and substantiated by a normal co-ordinate analysis carried out using a digital computer and the potential energy distributions of symmetry co-ordinates among the normal coordinates have also been calculated.
About: This article is published in Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy.The article was published on 1961-01-01. It has received 151 citations till now. The article focuses on the topics: Thionyl & Dimethyl sulfoxide.
Citations
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TL;DR: In this article, off-resonant transient birefringence measurements are analyzed using a reduced equation of motion for the ground state density matrix, which is expanded using an effective Hamiltonian.
Abstract: Off‐resonant transient birefringence measurements are analyzed using a reduced equation of motion for the ground state density matrix, which is expanded using an effective Hamiltonian. Assuming that the pump field is weak, we express the polarization relevant for the birefringence signal in terms of a convolution of the tensorial polarizability response function with the external fields. The homodyne‐detected birefringence signal is directly compared with the coherent Raman signal. The relationship between off‐resonant birefringence and spontaneous Raman experiments is discussed. By expanding the polarizability in powers of the nuclear coordinates and applying the Brownian oscillator model to the coordinate response function, we separate the birefringence signal into intra‐ and intermolecular coordinate response functions. Off‐resonant transient birefringences of acetonitrile, chloroform, dimethylsulfoxide, and a series of alcohols were measured. The data are transformed to the frequency domain by using a model independent analysis method. The spectra are discussed in the context of various models for the distribution of intermolecular modes (spectral density) in liquids.

240 citations

Journal ArticleDOI
TL;DR: It is found that methyl groups play different roles in response to the hydrogen-bonding interactions, namely the methyl groups of DMSO are electron-donating, whereas that of methanol is electron-withdrawing, both making positive contributions.
Abstract: When examining the formation energetics of a hydrogen-bonded complex R−X−H···Y−R‘, focus has been almost always on the atoms directly involved, namely the atoms X, Y, and H. Little attention has been paid to the effects of the secondary alkyl groups R and R'. Taking dimethyl sulfoxide (DMSO)−methanol binary system as an example, we have studied the roles of the alkyl groups in stabilizing the hydrogen bonds by employing FTIR and NMR techniques and quantum chemical calculations. We found that methyl groups play different roles in response to the hydrogen-bonding interactions. The methyl groups of DMSO are electron-donating, whereas that of methanol is electron-withdrawing, both making positive contributions. The findings reveal non-negligible effects of secondary alkyl groups in hydrogen bonding interaction and may shed light on the understanding of other more complicated hydrogen-bonded systems in chemical and biological systems.

168 citations

Journal ArticleDOI
TL;DR: In this article, the authors measured the intermolecular frequencies of water molecules in aqueous solutions of perdeuterated DMSO and DMSSO2 in order to determine, as a function of concentration and temperature, the influence of these compounds on the water structure.
Abstract: Molecular vibrations in solid and liquid dimethylsulphoxide (DMSO) and dimethylsulphone (DMSO2) have been measured by neutron inelastic scattering between 900–8 cm−1. Neutron spectra of the intermolecular frequencies of water molecules in aqueous solutions of perdeuterated DMSO and DMSO2 have also been measured to determine, as a function of concentration and of temperature, the influence of these compounds on the water structure. In addition, the broadening of the incident energy distribution by diffusive motions of H2O molecules has also been investigated. The similarity of intermolecular frequencies in the spectra of both the liquid and solid phases of the pure compounds shows a high degree of dipole association. In dilute aqueous solutions the DMSO and DMSO2 (hydrogenous and perdeuterated) both cause a similar enhancement and sharpening of the intermolecular frequencies of the water structure associated with a small and cooperative perturbation in the orientation of many H2O molecules. This is consist...

131 citations

Journal ArticleDOI
TL;DR: In this article, the infrared and Raman spectra of dimethylsulfoxide and dimethyl sulfoxide-d 6 have been re-investigated and new assignments are proposed based on comparison of the spectra and consideration of the polarisation of Raman lines.

119 citations

References
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TL;DR: Several microwave transitions of (CH3)3CH, (CH 3)3CF, and ( CH3) 3P have been measured and assigned as mentioned in this paper, and the properties of the microwave transitions have been determined.
Abstract: Several microwave transitions of (CH3)3CH, (CH3)3CF, and (CH3)3P have been measured and assigned. Rotational constants B0 for the three molecules are 7789.45, 4712.15, and 5816.24 Mc, respectively. Molecular structures and dipole moments have been determined. The (CH3)3CF structure indicates an unusually long CF bond. The prominent satellite lines have been assigned to excited vibrational states; the l‐type doubling pattern of transitions in degenerate states has been fitted to theory. Vibrational frequencies determined from relative intensity measurements agree with infrared and Raman results but indicate an incorrect species assignment in (CH3)3P. Frequencies of the torsional vibrations have been used to derive information of the potential function for internal rotation. The leading Fourier coefficient in this function is 3900, 4300, and 2600 cal/mole, respectively, for (CH3)3CH, (CH3)3CF, and (CH3)3P. The terms representing interactions among the CH3 groups are much smaller.

177 citations

Journal ArticleDOI

77 citations