scholarly journals Structure and vibrational spectroscopy of methanesulfonic acid

2018 ◽  
Vol 5 (12) ◽  
pp. 181363 ◽  
Author(s):  
Lisha Zhong ◽  
Stewart F. Parker
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bonding ◽  
Vibrational Spectroscopy ◽  
Density Functional ◽  
Inelastic Neutron Scattering ◽  
Linear Chain ◽  
Methanesulfonic Acid ◽  
Chain Structure ◽  
Trifluoromethanesulfonic Acid ◽  
Functional Theory

In this work, we have used a combination of vibrational spectroscopy (infrared, Raman and inelastic neutron scattering) and periodic density functional theory to investigate the structure of methanesulfonic acid (MSA) in the liquid and solid states. The spectra clearly show that the hydrogen bonding is much stronger in the solid than the liquid state. The structure of MSA is not known; however, mineral acids typically adopt a chain structure in condensed phases. A periodic density functional theory (CASTEP) calculation based on the linear chain structure found in the closely related molecule trifluoromethanesulfonic acid gave good agreement between the observed and calculated spectra, particularly with regard to the methyl and sulfonate groups. The model accounts for the large widths of the asymmetric S-O stretch modes; however, the external mode region is not well described. Together, these observations suggest that the basic model of four molecules in the primitive unit cell, linked by hydrogen bonding into chains, is correct, but that MSA crystallizes in a different space group than that of trifluoromethanesulfonic acid.

Hydrogen bonding in amylose/DMSO complexes studied by vibrational spectroscopy and density functional theory calculations

2009 ◽  
Vol 40 (9) ◽  
pp. 1110-1116 ◽  
Author(s):  
Alberto Milani ◽  
Nur Aiman Fadel ◽  
Luigi Brambilla ◽  
Mirella Del Zoppo ◽  
Chiara Castiglioni ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bonding ◽  
Vibrational Spectroscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory

scholarly journals Vibrational spectroscopy of metal methanesulfonates: M = Na, Cs, Cu, Ag, Cd

2018 ◽  
Vol 5 (4) ◽  
pp. 171574 ◽  
Author(s):  
Stewart F. Parker ◽  
Lisha Zhong
Keyword(s):  
Density Functional Theory ◽  
Vibrational Spectroscopy ◽  
Spectroscopic Data ◽  
Density Functional ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Functional Theory ◽  
Methyl Group ◽  
Transition Energies ◽  
Mode Of Coordination

In this work, we have used a combination of vibrational spectroscopy (infrared, Raman and inelastic neutron scattering) and periodic density functional theory to investigate six metal methanesulfonate compounds that exhibit four different modes of complexation of the methanesulfonate ion: ionic, monodentate, bidentate and pentadentate. We found that the transition energies of the modes associated with the methyl group (C–H stretches and deformations, methyl rock and torsion) are essentially independent of the mode of coordination. The SO 3 modes in the Raman spectra also show little variation. In the infrared spectra, there is a clear distinction between ionic (i.e. not coordinated) and coordinated forms of the methanesulfonate ion. This is manifested as a splitting of the asymmetric S–O stretch modes of the SO 3 moiety. Unfortunately, no further differentiation between the various modes of coordination: unidentate, bidentate etc … is possible with the compounds examined. While it is likely that such a distinction could be made, this will require a much larger dataset of compounds for which both structural and spectroscopic data are available than that available here.

Spectroscopies of rod- and pear-shaped nuclei in covariant density functional theory

2018 ◽  
Vol 27 (10) ◽  
pp. 1830007 ◽  
Author(s):  
Pengwei Zhao ◽  
Zhipan Li
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Linear Chain ◽  
Mean Field ◽  
Spectroscopic Properties ◽  
Chain Structure ◽  
Functional Theory ◽  
Covariant Density Functional Theory ◽  
Collective Hamiltonian ◽  
Covariant Density

The spectroscopic properties play a crucial role in understanding the structure of nuclei, in particular, the shape and shape transitions of nuclei. In recent years, the exotic shapes of nuclear systems, such as the rod and pear shapes, have attracted a lot of attention. Covariant density functional theory (CDFT) has become a standard tool for nuclear structure calculations, and it provides a global and accurate description of nuclear ground states and excitations. In the present paper, we briefly review the recent progress in covariant density functional theory (DFT) for spectroscopic properties of the rod- and pear-shaped nuclei with the cranking calculations in a rotating mean field and the collective Hamiltonian method beyond mean field. The novel linear-chain structure of alpha clustering is discussed with the cranking approach, and low lying spectra of pear-shaped nuclei are illustrated with the quadrupole–octupole collective Hamiltonian.

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