Critical Role of Non-classical Intermolecular Hydrogen Bonding in Affecting the π–π Stacking and Nonlinear Optical Properties of Tricyanofuran-Based Push–Pull Heptamethines

Currently, there is immense interest in the chemistry of push–pull heptamethines containing a strong acceptor of 2-dicyanomethylidene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TCF). This class of c...