Inverse-electron demand Diels Alder Reactions between glycals and tetrazines.

The inverse-electron demand Diels Alder reaction (IEDDA) of substituted tetrazines with 2,3-unsaturated sugars (glycals) has been investigated to prepare novel carbohydrate-based heterocycles. The cycloaddition reactions occurred in moderate to good, isolated yields and gave acyclic, C-linked pyranose diazines as the major products (33-90%). The effects of variations in sugars, sugar protecting groups, and reaction solvents on the yields and products obtained in these reactions were studied.

All-atom CHARMM force field and bulk properties of perfluorozinc phthalocyanines.

Classical force fields within the CHARMM parametrized model are developed for zinc phthalocyanines including the parent per-hydro molecule and per-fluoro-alkyl substituted derivatives. Partial atomic charges, 2-body bond lengths, and 3-body angle parameters were obtained from B3LYP-level density functional calculations. Force constants for 2-, 3-, and 4-body interactions were derived from existing fluoroalkane models and incorporated assuming transferability.

Molecular dynamic simulations of eicosanoic acid and 18-methyleicosanoic acid langmuir monolayers.

The conformational and dynamical properties of Langmuir monolayers of 18-methyleicosanoic acid (18-MEA) and the parent material, eicosanoic acid (EA), are compared using molecular dynamics simulations. The effects on various properties, including film thickness, tilt angle, and order parameter, of the methyl group at the 18 position in 18-MEA were investigated as a function of film-packing density. NVT simulations were run as a function of decreasing areal-packing density similar to experimental Langmuir-Blodgett film compressions and expansions.

Near-edge electronic structure in NbS2.

The near-edge electronic and structural properties of 2H-NbS(2) were investigated using scanning tunneling microscopy (STM) and density-functional calculations. Geometry optimization of the near-edge structure using density-functional calculations was performed on [1010]- and [1010]-terminated layer edges. Ribbon model systems also included variation of the number of bound sulfur atoms at the edges.