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)-1<i>H</i>-anthra­[1,2-<i>d</i>]­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

Design of Ru(II) Complexes Based on Anthraimidazoledione-Functionalized Terpyridine Ligand for Improvement of Room-Temperature Luminescence Characteristics and Recognition of Selective Anions: Experimental and DFT/TD-DFT Study

In this work we report synthesis and characterization of three rigid and linear rodlike monometallic Ru­(II) complexes based on a terpyridine ligand tightly connected to 9,10-anthraquinone electron-acceptor unit through phenyl–imidazole spacer. The motivation of designing these complexes is to enhance their excited-state lifetimes at room temperature. Interestingly it is found that all three complexes exhibit luminescence at room temperature with excited-state lifetimes in the range of 1.6–52.8 ns, depending upon the coligand as well as the solvent. Temperature-dependent luminescence investigations indicate that the energy gap between the emitting ³MLCT state and nonemitting metal-centered state ³MC in the complexes increased enormously compared with parent [Ru­(tpy)₂]²⁺. In addition, by taking advantage of the imidazole NH proton(s), which became appreciably acidic upon combined effect of electron accepting anthraquinone moiety as well as metal ion coordination, we also examined anion recognition and sensing behaviors of the complexes in organic, mixed aqueous–organic as well as in solid medium through different optical channels such as absorption, steady-state and time-resolved emission, and ¹H NMR spectroscopic techniques. In conjunction with the experiment, computational investigation was also employed to examine the electronic structures of the complexes and accurate assignment of experimentally observed spectral and redox behaviors

Hedgehog ZnO/Ag heterostructure: an environment-friendly rare earth free potential material for cold-white light emission with high quantum yield

Solid-state white light emission from environment-friendly, highly stable hedgehog ZnO/Ag heterostructure has been observed for first time from a combined effect of tunability of emission centers and charge transfer. The heterostructure has been synthesized via a facile low-temperature hydrothermal route and characterized using X-ray diffractometer, scanning electron microscope and transmission electron microscope. The interaction between ZnO and Ag can be confirmed from the appearance of few new multi-phonon Raman peaks. Steady-state photoluminescence spectrum reveals multiple emissions (413, 453, 546, 605 and 667 nm) from virgin hedgehog ZnO at an excitation wavelength of 325 nm. Tuneability of radiative and non-radiative emission of ZnO which is the primary mechanism for white light emission (CIE coordinate: 0.35, 0.32) has been briefly investigated by time-correlated single-photon spectroscopy. Biocompatible as well cost-effectivity depicts that the as-prepared heterostructure would be a promising solid-state white light-emitting phosphor material for long-term use