Dicyanobenzene and dicyanopyrazine derived X-shaped charge-transfer chromophores: comparative and structure-property relationship studyElectronic supplementary information (ESI) available: General information, synthesis and characterization of 11, further crystallographic, electrochemical, spectroscopic data, SHG results and HOMO/LUMO localizations in B1-B10, 1H and 13C NMR spectra of B1-B10. CCDC 984735 and 984736. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.

A series of novel X-shaped push-pull compounds based on benzene-1,2-dicarbonitrile has been designed, synthesized and further investigated by X-ray analysis, electrochemistry, absorption and emission spectra, SHG experiment and quantum-chemical calculations. The obtained data were compared with those for isolobal 5,6-disubstituted pyrazine-2,3-dicarbonitriles. Structure-property relationships were elucidated. The extension, composition and planarization of the π-linker used as well as the electron-withdrawing ability of both dicyano-substituted acceptor units affect the linear and nonlinear properties of the target charge-transfer chromophores most significantly. Structure-property relationships in X-shaped push-pull molecules with dicyanobenzene and dicyanopyrazine acceptors.