Structural diversities of charge transfer organic complexes. Focus on benzenoid hydrocarbons and 7,7,8,8-tetracyanoquinodimethane†
We have obtained three-component systems: the complexes comprising of two different benzenoid hydrocarbons together with one molecule of 7,7,8,8-tetracyanoquinodimethane (TCNQ). The X-ray single-crystal structures of naphthalene–perylene–TCNQ and pyrene–perylene–TCNQ revealed that they form face-to-face stacking between perylene and TCNQ molecules containing another hydrocarbon as a guest in the structure. We also present a pyrene–TCNQ complex with two pyrene moieties acting in similar way. In this system, charge transfer is far more efficient than in any other complexes of TCNQ with benzenoid hydrocarbons. Additionally, we have also obtained as references pyrene–TCNQ, chrysene–TCNQ, phenanthrene–TCNQ and naphthalene–TCNQ with 1 : 1 molecular ratios. These systems were also used to estimate the degrees of charge transfer.