Two-dimensional sheet based on C–H···N hydrogen bonds within an organic cocrystal: a crystallographic, spectroscopic and theoretical study

The cocrystal containing 1,2,4,5-tetracyanobenzene (TCNB) and trans-1,2-bis(4-pyridyl)ethylene (4,4′-BPE) has been realised (TCNB)·(4,4′-BPE) 1. Compound 1 produces a two-dimensional sheet based on two different types of C–H···N hydrogen bonds. Each molecule within the cocrystal functions as both a donor and an acceptor of hydrogen bonds. Weak hydrogen bonds such as these, acting as the driving force to produce a polymeric assembly, are not investigated as frequently as stronger and more traditional O–H···O and O–H···N hydrogen bonds within multicomponent cocrystals. The existence of the different types of C–H···N hydrogen bonds was confirmed by single-crystal X-ray diffraction as well as infrared spectroscopy. The overall interaction energies for both types of hydrogen bonds were determined by computational calculations at various levels of theory.