Conformational preferences of the benzenedicarbaldehydes: an ab initio molecular-orbital, dipole-moment and Kerr-effect study

1984 ◽  
Vol 37 (3) ◽  
pp. 465 ◽  
Author(s):  
D Mirarchi ◽  
L Phillips ◽  
H Lumbroso ◽  
GLD Ritchie
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Kerr Effect ◽  
Dipole Moments ◽  
Effect Study ◽  
Molecular Orbital Theory ◽  
Orbital Theory ◽  
Molecular Plane ◽  
Conformational Preferences ◽  
Kerr Constants

Ab initio molecular orbital theory at the STO-3G level is used to elucidate the structures and relative abundances of stable conformations of the three benzenedicarbaldehydes. In addition, new measurements of the infinite-dilution dipole moments and molar Kerr constants of these molecules as solutes in dioxan at 25�C are reported and analysed. The previously recognized inability of the simple group- additivity model to reliably predict the anisotropy in the polarizability of benzene-1,4-dicarbaldehyde is shown to be due to a redistribution of the polarizability in the molecular plane.

Conformations of vinyl formate and vinyl acetate

1976 ◽  
Vol 29 (3) ◽  
pp. 581 ◽  
Author(s):  
MJ Aroney ◽  
EAW Bruce ◽  
IG John ◽  
L Radom ◽  
GLD Ritchie
Keyword(s):  
Carbon Tetrachloride ◽  
Ab Initio ◽  
Gas Phase ◽  
Vinyl Acetate ◽  
Molecular Orbital ◽  
Dipole Moments ◽  
Molecular Orbital Theory ◽  
Orbital Theory ◽  
Theoretical Predictions ◽  
Kerr Constants

Ab initio molecular orbital theory has been used to deduce the preferred gas-phase conformations of vinyl formate and vinyl acetate. In addition, experimental dipole moments (1030μ/Cm) and molar Kerr constants (1027mK/m5 V-2 mol-1) at 25�C are reported for both molecules as solutes in carbon tetrachloride: vinyl formate (5.07, + 48.1) and vinyl acetate (5.70, + 3.8). The preferred solution-state conformations indicated by the analysis of these results are shown to be consistent with the theoretical predictions.

Creation of a Simple Stable Enol. The Stabilizing Properties of the Diazonium Substituent

1979 ◽  
Vol 32 (7) ◽  
pp. 1401 ◽  
Author(s):  
MJ Ballard ◽  
WJ Bouma ◽  
L Radom ◽  
MA Vincent
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Electron Acceptor ◽  
Vinyl Alcohol ◽  
Molecular Orbital Theory ◽  
Orbital Theory ◽  
Conformational Preferences ◽  
Alcohol System ◽  
Optimized Geometries

Ab initio molecular orbital theory is used to examine the effect of the diazonium substituent (N2+) on the keto-enol equilibrium in the acetaldehyde/vinyl alcohol system. The conformational preferences of the two isomers are examined, and optimized geometries obtained for the best conformers. The diazonium substituent is a strong π-electron acceptor and σ-electron acceptor, and accordingly destabilizes the keto isomer and stabilizes the enol isomer. The effect of the diazonium substituent is sufficiently large to make the enol isomer substantially lower in energy than the keto isomer.

Keto-enol tautomerism. Relative stabilization of enol isomers

1978 ◽  
Vol 31 (6) ◽  
pp. 1167 ◽  
Author(s):  
WJ Bouma ◽  
L Radom
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Vinyl Alcohol ◽  
Energy Difference ◽  
Molecular Orbital Theory ◽  
Orbital Theory ◽  
Conformational Preferences ◽  
Relative Stabilization ◽  
Alcohol System ◽  
Li Substitution

Ab initio molecular orbital theory is used to examine the effect of simple π-electron-accepting substituents (Li, BeH, BH2) on the keto-enol equilibrium in the acetaldehyde-vinyl alcohol system. The enol-keto energy difference is increased slightly by α-Li substitution and decreased to a near-zero value by a BH2 substituent. The results are rationalized in terms of geminal interactions. The conformational preferences of substituted acetaldehyde systems (XCH2CHO; X = Li, BeH, BH2, CH3, F) are discussed. Three classes of rotational potential functions are distinguished on the basis of the σ-electron-donating or -accepting nature of the substituent.

Ab initio molecular orbital theory

1986 ◽  
Vol 119 (2) ◽  
pp. 234 ◽  
Author(s):  
Luigi Olcari
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Molecular Orbital Theory ◽  
Orbital Theory

The Heat of Formation of Formaldimine

1992 ◽  
Vol 45 (1) ◽  
pp. 285 ◽  
Author(s):  
BJ Smith ◽  
JA Pople ◽  
LA Curtiss ◽  
L Radom
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Heat Of Formation ◽  
Molecular Orbital Theory ◽  
Orbital Theory

Ab initio molecular orbital theory at the G 2 level has been used to predict new values for the heat of formation of formaldimine (CH2=NH): ?Hfº0 = 94 ±10 kJ mol-1 and ?Hfº298 = 86 ±10 kJ mol-1.

Enthalpies of Formation of Gas-Phase N3, N3-, N5+, and N5-from Ab Initio Molecular Orbital Theory, Stability Predictions for N5+N3-and N5+N5-, and Experimental Evidence for the Instability of N5+N3-

2004 ◽  
Vol 126 (3) ◽  
pp. 834-843 ◽  
Author(s):  
David A. Dixon ◽  
David Feller ◽  
Karl O. Christe ◽  
William W. Wilson ◽  
Ashwani Vij ◽  
...  
Keyword(s):  
Ab Initio ◽  
Experimental Evidence ◽  
Gas Phase ◽  
Molecular Orbital ◽  
Enthalpies Of Formation ◽  
Molecular Orbital Theory ◽  
Orbital Theory

Ab initio molecular orbital theory: a tool for THz spectroscopic investigation

2005 ◽  
Author(s):  
Inke Jones ◽  
Tamath J. Rainsford ◽  
Samuel P. Mickan ◽  
Derek Abbott
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Spectroscopic Investigation ◽  
Molecular Orbital Theory ◽  
Orbital Theory

ChemInform Abstract: THE RELATIONSHIP BETWEEN SUBSTITUENT EFFECTS ON ENERGY AND ON CHARGE FROM AB INITIO MOLECULAR ORBITAL THEORY

1977 ◽  
Vol 8 (47) ◽  
pp. no-no
Author(s):  
W. F. REYNOLDS ◽  
P. G. MEZEY ◽  
W. J. HEHERE ◽  
R. D. TOPSOM ◽  
R. W. TAFT
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Substituent Effects ◽  
Molecular Orbital Theory ◽  
Orbital Theory ◽  
The Relationship
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