Structure of 1-Naphthol−Water Clusters Studied by IR Dip Spectroscopy and Ab Initio Molecular Orbital Calculations

1998 ◽  
Vol 102 (31) ◽  
pp. 6227-6233 ◽  
Author(s):  
Ruriko Yoshino ◽  
Kenro Hashimoto ◽  
Takuichiro Omi ◽  
Shun-ichi Ishiuchi ◽  
Masaaki Fujii
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Water Clusters ◽  
Molecular Orbital Calculations

Structure of 1-naphthol–water clusters in the S1 state studied by UV–IR fluorescence dip spectroscopy and ab initio molecular orbital calculations

2013 ◽  
Vol 557 ◽  
pp. 19-25 ◽  
Author(s):  
Toshihiko Shimizu ◽  
Ruriko Yoshino ◽  
Shun-ichi Ishiuchi ◽  
Kenro Hashimoto ◽  
Mitsuhiko Miyazaki ◽  
...  
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Water Clusters ◽  
Molecular Orbital Calculations

Ab initio molecular-orbital calculations for dodecahedral water clusters including rare-gas atoms

2003 ◽  
Vol 81 (1-2) ◽  
pp. 33-38 ◽  
Author(s):  
A Hori ◽  
T Hondoh
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Water Clusters ◽  
Chemical Shifts ◽  
Rare Gas ◽  
Molecular Orbital Calculations ◽  
Rare Gas Atoms ◽  
In The Beginning ◽  
Cohesive Energies ◽  
First Time

Dodecahedral water clusters including rare-gas atoms and molecules are considered to play an important role in the beginning of the formation of gas hydrates in solutions. To investigate their stability, ab initio molecular-orbital calculations were performed at the MP2/6-311G(d,p)//HF/6-311G(d,p) level. In He, Ne, Ar, and Kr, the cohesive energies of the 12-hedral water clusters including each rare-gas atom were negative, whereas in Xe they were positive. Neon in the dodecahedral cluster was almost as stable as Ar and Kr in the dodecahedral clusters; the latter two are known as clathrate-forming gases. This suggests the probability of the existence of Ne clathrate hydrate, which is generally considered to be impossible. The chemical shifts of Xe incorporated in polyhedral water clusters were computed for the first time. The computed values qualitatively agree with the experimental results. PACS Nos.: 31.15Ar, 31.15Md, 31.15Ne, 36.40Cg, 36.40Mr

A pairwise additivity scheme for conformational energies of substituted ethanes

1975 ◽  
Vol 343 (1632) ◽  
pp. 1-10 ◽  
Keyword(s):  
Large Deviations ◽  
Ab Initio ◽  
Dihedral Angle ◽  
Molecular Orbital ◽  
Methyl Groups ◽  
Molecular Orbital Calculations ◽  
Linear Combinations ◽  
Strongly Interacting ◽  
Conformational Energies

Ab initio molecular orbital calculations are used to explore additivity in the conformational energies of poly-substituted ethanes in terms of conformational energies of ethane and appropriate mono- and 1,2-di-substituted derivatives. Such relations would allow complex calculations for poly-substituted ethanes to be replaced by much simpler ones on a small number of parent molecules. General expressions for the linear combinations are derived from the assumption that interactions between vicinal substituents are pairwise additive and depend only on the vicinal dihedral angle. The additivity scheme is tested for 15 ethanes, di-, tri- or tetrasubstituted by cyano and methyl groups and for a smaller number of fluoroethanes. Additivity applies to within 0.1- 0.3 k J mol -1 in the methylethanes and mostly to within about 0.7- 0.8 kJ mol -1 in cyanoethanes. Large deviations are found among the geminally substituted fluoroethanes. It is suggested that the additivity approximation is most successful in the absence of strongly interacting geminal groups. Predictions are made of conformational energies of ten hexa(cyano- and methyl-) substituted ethanes.

Gas-Phase Tautomerism in the Triazoles and Tetrazoles: A Study by Photoelectron Spectroscopy and ab Initio Molecular Orbital Calculations

1981 ◽  
Vol 36 (11) ◽  
pp. 1246-1252 ◽  
Author(s):  
Michael H. Palmer ◽  
Isobel Simpson ◽  
J. Ross Wheeler
Keyword(s):  
Ab Initio ◽  
Gas Phase ◽  
Molecular Orbital ◽  
Photoelectron Spectroscopy ◽  
Relative Stability ◽  
Photoelectron Spectra ◽  
Equilibrium Geometry ◽  
Molecular Orbital Calculations ◽  
Methyl Derivatives

The photoelectron spectra of the tautomeric 1,2,3,- and 1,2,4-triazole and 1,2,3,4-tetrazole systems have been compared with the corresponding N-methyl derivatives. The dominant tautomers in the gas phase have been identified as 2 H-1,2,3-triazole, 1 H-1,2,4-triazole and 2H-tetrazole.Full optimisation of the equilibrium geometry by ab initio molecular orbital methods leads to the same conclusions, for relative stability of the tautomers in each of the triazoles, but the calculations wrongly predict the tetrazole tautomerism.

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