Vapor phase association in acetic and trifluoroacetic acids. Thermal conductivity measurements and molecular orbital calculations

1980 ◽  
Vol 102 (8) ◽  
pp. 2610-2616 ◽  
Author(s):  
D. J. Frurip ◽  
L. A. Curtiss ◽  
M. Blander
Keyword(s):  
Thermal Conductivity ◽  
Molecular Orbital ◽  
Vapor Phase ◽  
Molecular Orbital Calculations ◽  
Conductivity Measurements

Experimental and theoretical estimates of the internal rotational barrier of benzyl fluoride in the vapor phase

1990 ◽  
Vol 68 (4) ◽  
pp. 581-586 ◽  
Author(s):  
Ted Schaefer ◽  
Christian Beaulieu ◽  
Rudy Sebastian ◽  
Glenn H. Penner
Keyword(s):  
Molecular Orbital ◽  
Vapor Phase ◽  
Phenyl Group ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Basis Sets ◽  
Molecular Orbital Calculations ◽  
Stable Conformer ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling

The twofold barrier to rotation about the [Formula: see text] bond in benzyl fluoride is deduced from the long-range 1H,1H; 1H,19F; and 13C,19F nuclear spin–spin coupling constants in solution. The barrier changes from 3.2(2) kJ/mol in the polar solvent, acetonitrile-d3, to 0.7(2) kJ/mol in the nonpolar environment provided by cyclohexane-d12. In all solutions the conformer of greatest stability has the C—F bond in a plane perpendicular to that of the phenyl group. Extrapolation of the barrier to the vapor phase, using a simple reaction field model, indicates that the most stable conformer for the free (unclustered) molecule is now that with the C—F bond in the phenyl plane and that the barrier to internal rotation is 1.1(7) kJ/mol. Molecular orbital calculations with the basis sets STO-3G, 4-21G, 4-31G, 6-31G, and 6-31G* all predict the latter conformer as that of lowest energy. However, they disagree significantly among themselves as to the height of the internal barrier. The complete geometries are given for both conformers, as computed with the 6-31G basis, and the side-chain geometries are tabulated for the planar and perpendicular conformers, as given by all the bases. Keywords: benzyl fluoride, internal rotational potential; 13C,19F spin–spin coupling constants in benzyl fluoride; benzyl fluoride, molecular orbital computations.

Interactions between Methylene Blue and Pullulan According to Molecular Orbital Calculations

2020 ◽  
Vol 140 (11) ◽  
pp. 529-533
Author(s):  
Pasika Temeepresertkij ◽  
Saranya Yenchit ◽  
Michio Iwaoka ◽  
Satoru Iwamori
Keyword(s):  
Methylene Blue ◽  
Molecular Orbital ◽  
Molecular Orbital Calculations
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