A Model Theoretical Study for Alkylation in Benzimidazoles: ab initio Electrostatic Potentials

1979 ◽  
Vol 32 (1) ◽  
pp. 11 ◽  
Author(s):  
AL Hinde ◽  
L Radom ◽  
M Rasmussen
Keyword(s):  
Experimental Data ◽  
Ab Initio ◽  
Molecular Orbital ◽  
Electrostatic Potential ◽  
Molecular Electrostatic Potential ◽  
Theoretical Study ◽  
Molecular Orbital Theory ◽  
Frontier Orbital ◽  
Orbital Theory ◽  
Controlled Processes

Ab initio molecular orbital theory is used to study the protonation of benzimidazole anions. Both kinetically and thermodynamically controlled processes are considered for the unsubstituted and for NH2, NO2 and CN substituted systems. Extensive use is made of molecular electrostatic potential (m.e.p.) maps to predict kinetically preferred sites of protonation. Predictions made on this basis are consistent with experimental data on alkylation of these and closely related systems. In contrast, other approaches based on theoretical charges or frontier orbital coefficients do not correlate well with the experimental results.

Internal rotation in some organic molecules containing methyl, amino, hydroxyl, and formyl groups

1972 ◽  
Vol 25 (8) ◽  
pp. 1601 ◽  
Author(s):  
L Radom ◽  
WA Lathan ◽  
WJ Hehre ◽  
JA Pople
Keyword(s):  
Experimental Data ◽  
Ab Initio ◽  
Internal Rotation ◽  
Molecular Orbital ◽  
Organic Molecules ◽  
Experimental Information ◽  
Molecular Orbital Theory ◽  
Orbital Theory ◽  
Moderate Agreement ◽  
Theoretical Results

Ab initio molecular orbital theory is used to study internal rotation in 20 organic molecules of the types X-Y, X-CH2-Y, X-SH-Y, X-O-Y, and X-CO-Y-where X and Y are methyl, amino, hydroxy, or formyl groups. In some of these molecules, internal rotation about two bonds is possible. The theoretical results are generally in moderate agreement with available experimental data and, in addition, lead to a number of predictions for molecules for which experimental information is lacking.

Understanding Metal-Free Catalytic Hydrogenation: A Systematic Theoretical Study of the Hydrogenation of Ethene

2004 ◽  
Vol 57 (7) ◽  
pp. 659 ◽  
Author(s):  
Bun Chan ◽  
Leo Radom
Keyword(s):  
Catalytic Activity ◽  
Ab Initio ◽  
Proton Affinity ◽  
Molecular Orbital ◽  
Catalytic Hydrogenation ◽  
Theoretical Study ◽  
Molecular Orbital Theory ◽  
Orbital Theory ◽  
Metal Free ◽  
High Level

Metal-free catalytic hydrogenation of ethene has been examined using high-level [G3(MP2)-RAD] ab initio molecular orbital theory. The dependence of the catalytic activity on the nature of the catalyst Z–X–H has been explored. We find that the catalytic activity is generally greater as Z–X–H becomes more acidic, both for first- and second-row atoms X. Molecules in which X is a second-row atom generally lead to more effective catalysis than the corresponding first-row analogues. The proton affinity at X of Z–X–H also contributes significantly to the catalysis in some cases (e.g. amines).

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.

scholarly journals Ab initio study regarding the evaluation of the antioxidant character of cyanidin, delphinidin and malvidin

2012 ◽  
Vol 10 (1) ◽  
pp. 180-186 ◽  
Author(s):  
Raluca Pop ◽  
Mariana Ştefănut ◽  
Adina Căta ◽  
Cristian Tănasie ◽  
Mihai Medeleanu
Keyword(s):  
Ab Initio ◽  
Theoretical Study ◽  
Molecular Descriptors ◽  
Frontier Molecular Orbital ◽  
Hydroxyl Groups ◽  
Molecular Orbital Theory ◽  
Ab Initio Study ◽  
Wide Spread ◽  
Orbital Theory ◽  
Dissociation Enthalpy

AbstractA theoretical study regarding the evaluation of the antioxidant character of three of the most wide-spread anthocyanidins (cyanidin, delphinidin and malvidin) was carried out at ab initio level. Different parameters (bond dissociation enthalpy, ionization potential, proton affinity, and electron transfer enthalpy) were computed for each OH group of the compounds in order to predict their antioxidant capacity. Several molecular descriptors based on frontier molecular orbital theory (hardness, electrophilicity, frontier charge density) were also calculated, as well as the atomic charges corresponding to the O atoms of the hydroxyl groups.

Sign in / Sign up

Export Citation Format

Share Document