carbon nanotubes (cnts) are specific structures with valuable characteristics. in general, the structure of each nanotube is defined by a unique chiral vector. in this paper, different structures of short single-walled cnts are simulated and their mechanical properties are determined using finite element method. for this aim, a simple algorithm is presented which is able to model the geometry o...

One of the problems encountered in CE separations of basic compounds is the adsorption of analytes onto the negatively charged capillary wall which could lead to poor repeatability of migration time and peak area. Additionally, separation of enantiomers of chiral of basic drugs is commonly carried out in low pH buffer which contributes to strong ionic interaction of the cationic drug ions with ...

A new class of aminocyclitol derivatives with the bicyclo[4.2.0]octane skeleton was synthesized starting from cyclooctatetraene. Photooxygenation of trans-7,8-diacetoxy- and cis-7,8-dichlorobicyclo[4.2.0]octa-2,4-diene afforded the bicyclic endoperoxides. Reduction of the latter with thiourea followed by a Pd(0) catalyzed ionization/cyclization reaction gave the corresponding oxazolidinone deri...

The title compound, C(21)H(21)N(3)O(7)S, contains an oxazolidinone ring and a sulfonamide group, both characteristic for biologically and pharrmaceutically active compounds. Both stereogenic centres reveal an S absolute configuration. The two oxazolidinone rings are in an envelope conformation with the methyl-ene carbon flap atoms deviating by 0.428 (1) and 0.364 (2) Å from the best least-squar...

An important property of electromagnetic fields, which arises from the interaction between fields and chiral molecules, is called optical chirality. By enhancing this field property, while maintaining constant input power, we are able to increase absorption of circularly polarized light by chiral molecules of a certain handedness. This enhancement is achieved through the use of achiral plasmoni...

One of the problems encountered in CE separations of basic compounds is the adsorption of analytes onto the negatively charged capillary wall which could lead to poor repeatability of migration time and peak area. Additionally, separation of enantiomers of chiral of basic drugs is commonly carried out in low pH buffer which contributes to strong ionic interaction of the cationic drug ions with ...

In the title compound, C(19)H(19)BrN(2)O(2)S, the central thieno-pyrim-idine ring system is essentially planar, with a maximum displacement of 0.068 (3) Å. The attached cyclo-hexene ring adopts a half-chair conformation. The molecular conformation and crystal packing are stabilized by three intra-molecular C-H⋯O hydrogen bonds and two C-H⋯π inter-actions.

Physical and chemical quenching rate constants were measured for the reaction of singlet oxygen with oxazolidinone-functionalized enecarbamates to investigate the role of vibrational deactivation in product stereoselectivity.

We study the D → σπ, D → ρπ, B− → σπ−, B− → ρ0π− and B̄ → ρ±π∓ decays in a valence quark triangle model, incorporating chiral symmetries. We find a good agreement with recent experimental data for D → σπ and for D → ρπ. We point out that a long-distance contribution due to the axial vector a1 meson pole, calculated by using chiral symmetry, can be relevant to explain D → ρπ and for lowering the ...