Anthraimidazoledione-Terpyridine-Based Optical Chemosensor for Anions and Cations That Works As Molecular Half-Subtractor, Key-Pad Lock, and Memory Device

We designed in this work a new family of anthraquinone and imidazole functionalized bifunctional terpyridine receptor, 2-(4-(2,6-di­(pyridine-4-yl)­phenyl)-1H-anthra­[1,2-d]­imidazole-6,11-dione (tpy-HPhImz-Anq) for recognition and sensing of selective anions and cations as well as for the construction of multifunctional logic devices. The terpyridine motif in the receptor was utilized for the cation coordination site and the imidazole moiety as the anion binding site. Both anion and cation recognition aspects of the receptor were thoroughly investigated in acetonitrile, mixed DMSO–water, as well as in solid media via different optical channels such as absorption, steady state, and time-resolved emission spectroscopic techniques. On the basis of the absorption and emission spectral responses toward a specific set of ionic inputs, this unique bifunctional receptor can mimic several advanced logic functions such as those of half-subtractor, key-pad lock, and memory device. We also report the implementation of the fuzzy logic approach to develop an infinite-valued logic system based on the luminescence dependence of the receptor upon concentration of different ionic inputs. In conjunction with the experimental investigation, density functional theory (DFT), and time-dependent density functional theory (TD-DFT), studies were carried out to investigate the structural and electronic properties of the receptor.