Structure and conformation of meso-2,4-di(N-carbazolyl)pentane

The stereochemistry of the title compound is established as meso. The carbazole groups have no parallel planar close contacts (π-type interactions), which differs from the packing found previously for terminal 1,n-di(N-carbazolyl)alkanes. Bond distances, bond angles, and torsion angles are compared with those calculated for the isolated molecule using M06-2X density functional theory, which is designed to model intramolecular dispersion effects. The results indicate that dispersion effects have a significant influence on the molecular conformation, although packing effects likely determine the magnitude of the puckering about one of the nitrogens (N1) and give a crystal conformation closer to a theoretical local minimum than to the global minimum potential energy, which are calculated to differ by only 6.7 kJ/mol at 298 K.