• Bulletin of the Korean Chemical Society
• /
• 제30권3호
• /
• pp.719-721
• /
• 2009

• Bulletin of the Korean Chemical Society
• /
• 제34권8호
• /
• pp.2511-2514
• /
• 2013

• 대한화학회지
• /
• 제57권6호
• /
• pp.677-683
• /
• 2013

A theoretical study of the electronic structures of $TiC_{1-x}$ and $Ti_{1-x}W_xC$ (x = 0, 0.25) is presented. The density of states and crystal orbital overlap population calculations were used to interpret variations of elastic properties induced by carbon vacancies and alloying substitutions. Our results show why the introduction of vacancies into TiC reduces bulk moduli, while W substitution at a Ti site increases the elastic modulus. The effect of the point defects on the bonding in TiC is investigated by means of extended Huckel tight-binding band calculations.

• Bulletin of the Korean Chemical Society
• /
• 제24권5호
• /
• pp.661-663
• /
• 2003

• Bulletin of the Korean Chemical Society
• /
• 제27권1호
• /
• pp.59-64
• /
• 2006

Unlike other viral polymerases, HCV RNA-dependent RNA polymerase (RdRp) has not been successfully inhibited by nucleoside analogues presumably due to its strong substrate specificity for RNA. Thus, in order to understand the RNA-specificity of HCV RdRp, the structural characteristics of the active site was investigated. The hereto unknown 2-OH binding pocket at the active site of RdRp provides invaluable implication for the development of novel anti-HCV nucleoside analogues.

• Bulletin of the Korean Chemical Society
• /
• 제27권11호
• /
• pp.1791-1794
• /
• 2006

We have introduced a new enantioselective receptor 1 by incorporation of chiral building blocks to the previously reported carboxylate selective receptor 2. Binding studies carried out using $^1H$ NMR revealed that the receptor 1 showed moderate enantioselectivity with a general preference for D-amino acids and a highest enantioselectivity for leucine among the amino acids we investigated.

• Bulletin of the Korean Chemical Society
• /
• 제24권5호
• /
• pp.681-683
• /
• 2003

• Bulletin of the Korean Chemical Society
• /
• 제12권5호
• /
• pp.515-517
• /
• 1991

The electronic behavior of a organic metal $(BEDT-TTE)_2$${Cu_5}{I_6}$ observed to be stable at low temperatures was examined by performing tight-binding band electronic structure calculations. The suppression of a metal-insulator tansition is likely to originate from its quasi-two-dimensional Fermi surface with no nesting, in agreement with experiment.

• Bulletin of the Korean Chemical Society
• /
• 제19권6호
• /
• pp.628-634
• /
• 1998

The properties of the n-type impurities nitrogen and phosphorus in diamond have been investigated by means of electronic band structure calculations within the framework of the semiempirical extended Huckel tight-binding method. For diamond with the nitrogen and phosphorus substitutional impurities, calculated density of states shows the impurity level deep in the band gap. This property can be derived from the substantial <111> relaxation of the impurity and nearest-neighbor carbon atoms, which is associated with the population of an antibonding orbital between them. The passivated donor property of the P-vacancy complex which lies deep in the gap is also discussed.

• Bulletin of the Korean Chemical Society
• /
• 제14권5호
• /
• pp.631-635
• /
• 1993

The polarizability and the transition state energy of a cephalosporin are assumed to be theoretical indices of the permeability through the outer membrane and of reactivity of ${\beta}$ -lactam ring with penicillin binding proteins, respectively, in Gram-negative bacteria. They are computed by AM1 method and used as variables of quantitative structure-activity relationship study. The results justify quadratic dependence of the activity on the variables. The intersection of difference volumes between $\beta-lactamase$ stable cephalosporins and unstable ones manifests that the steric hindrance of 7-side chain is responsible for the ${\beta}$ -lactamase stability.