Hueckel molecular orbital calculations of the index of aromatic stabilization of polycyclic conjugated molecules

1972 ◽  
Vol 37 (1) ◽  
pp. 139-141 ◽  
Author(s):  
N. Trinajstic ◽  
M. Milun ◽  
Z. Sobotka
Keyword(s):  
Molecular Orbital ◽  
Molecular Orbital Calculations ◽  
Conjugated Molecules ◽  
Aromatic Stabilization

Molecular orbital calculations for conjugated molecules containing boron and nitrogen

1967 ◽  
Vol 45 (18) ◽  
pp. 2059-2070 ◽  
Author(s):  
N. C. Baird ◽  
M. A. Whitehead
Keyword(s):  
Molecular Orbital ◽  
Bond Order ◽  
Molecular Orbital Calculations ◽  
Conjugated Molecules ◽  
Boron Nitrogen

The Π-electron networks in boron–nitrogen chains and rings have been treated by l.c.a.o.–m.o. techniques. The results for B—N chains predict a very weak alternation of bond order, smaller charges on the terminal atoms than on the internal atoms, and very little conjugation across B—B and N—N linkages. The calculations for the B—N rings predict an absence of a "4n + 2" pi-electron rule for aromaticity and a predominance of exocyclic over endocyclic Π bonding in the substituted rings. These results are compared with the properties of known B—N chains and rings and are contrasted with l.c.a.o.–m.o. calculations for the analogous carbon–carbon systems.

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

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.

ChemInform Abstract: MOLECULAR ORBITAL CALCULATIONS ON THE C2H4SH+ CATION

1976 ◽  
Vol 7 (10) ◽  
pp. no-no
Author(s):  
JAMES W. GORDON ◽  
GEORGE H. SCHMID ◽  
IMRE G. CSIZMADIA
Keyword(s):  
Molecular Orbital ◽  
Molecular Orbital Calculations
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