Helices of boron-nitrogen hexagons and decagons. A theoretical study.
Ab initio self-consistent field molecular orbital and density functional theory calculations have been performed on a series of helical boron-nitrogen structures comprised of fused hexagons and larger polygons. The presence of an even number N of rings in the boron-nitrogen [N]helicenes leads to the possibility of angular isomers. The electronic structure and stability of three isomeric nonhydrogenated boron-nitrogen helices were investigated at the HF/6-31G(d) and the B3LYP/6-31G(d) levels of theory. According to this study some of the initially assumed regular helical structures are unstable; two types of the isomeric structures convert to characteristically different equilibrium geometries. Electron density contours were calculated in order to interpret the existing bonding patterns.
Szakacs
Csaba E
CE
Department of Chemistry, Scientific Modeling and Simulation Laboratory, Memorial University of Newfoundland, St John's, NL A1B 3X7, Canada.
Mezey
Paul G
PG