The potential energy surfaces for the chemical reactions of group 14 carbenes have been studied using density functional theory (B3LYP/LANL2DZ). Five saturated five-membered-ring N-heterocyclic carbene Dipp[upper bond 1 start]N(CH(2))(2)N(Dipp)E[upper bond 1 end]: (five-ring-E:) species, where E = C, Si, Ge, Sn and Pb, have been chosen as model reactants in this work. Also, four kinds of chemic...

The one-dimensional model of Lippincott and Schroeder for hydrogen bond has Been re-examined and it has been shown that O-H bond distance depends on repulsive van der Waals and attractive electrostatic potentials.it has been shown that constant b in the van der Waals repulsion potential is not transferable to all hydrogen bonds. The possibility of obtaining the semi-empircal parameters i...

In this research at the first, xylometazoline hydrochloride drug (XY) and its fullerene connected form (FXY) were optimized. Natural Bond Orbital (NBO) calculations for these compounds were carried out at the B3LYP/6-31G* quantum chemistry level, in the gas phase and the liquid phase. These calculations can be performed at different accuracy levels depending on the aim of the theoretical study....

In this research at the first, captopril drug (CA) and its fullerene connected form (FCA) wereoptimized. Natural Bond Orbital (NBO) calculations for these compounds were carried out at theB3LYP/6-31G quantum chemistry level, in the gas phase and the liquid phase. These calculations canbe performed at different accuracy levels depending on the aim of the theoretical study [1]. Forinstance, Densi...

An attempt is made to explain the E-C formalism for ionic interactions in terms of the ionic approximation to chemical bonding. Dravo's E-C equation is seen to be a first approximation to the bond energy equation as it is given by the ionic bonding approach. The meaning of the ratio C/E is discussed and its relation with the hardness and softness of interacting species, as these occur in Pearso...

A novel method to combine quantum mechanics (QM) and molecular mechanics has been developed to accurately and efficiently account for covalent bond breaking in polymer systems under high strain without the use of predetermined break locations. Use of this method will provide a better fundamental understanding of the mechano-chemical origins of fracture in thermosets. Since classical force field...

In this research at the first, xylometazoline hydrochloride drug (XY) and its fullerene connected form (FXY) were optimized. Natural Bond Orbital (NBO) calculations for these compounds were carried out at the B3LYP/6-31G* quantum chemistry level, in the gas phase and the liquid phase. These calculations can be performed at different accuracy levels depending on the aim of the theoretical study....