Anion-and pH-sensing behaviors of an imidazole-dicarboxylatebased Ru(II)−bipyridine complex possessing a number of dissociable protons in its secondary coordination sphere are employed here for the creation of multiple Boolean and fuzzy logic systems. The absorption, emission, and electrochemical behaviors of the metalloreceptor were significantly modulated upon the influence of basic anions (such as F − , AcO − , and H 2 PO 4 − ) as well as by altering the pH of the solution. Interestingly, the deprotonation of the metalloreceptor by selected anions or by alkaline pH, followed by its restoration to its original form by acid or acidic pH is reversible and could be repeated many times. The metalloreceptor is capable to demonstrate several advanced Boolean functions, namely, three-input OR gate, set−reset flip-flop logic, and traffic signal, by employing its electrochemical responses through proper use of different inputs. Administering exhaustive sensing experiments by changing the analyte concentration within a wide range is usually tedious as well as exorbitantly costly. To get rid of these difficulties, we employed here several soft computing approaches such as artificial neural networks (ANN), fuzzy logic systems (FLS), or adaptive neuro−fuzzy inference system (ANFIS) to foresee the experimental sensing data and to appropriately model the protonation−deprotonation behaviors of the metalloreceptor. Reasonably good correlation between the experimental and model output data is also reflected in their tested root-mean-square error values (0.115961 and 0.118894 for the ANFIS model).

We report herein the synthesis, photophysics, and electrochemistry of three Ru­(II)–terpyridine complexes derived from a new terpyridyl–imidazole ligand (tpy-HImzPh 3 F 2 ) and study their pH- and temperature-responsive behaviors toward the fabrication of molecular switches. The complexes emitted at room temperature (RT) have a lifetime within the 4.5–49.0 ns domain, depending on the auxiliary ligand and the solvent used. In the acidic region, the complexes exhibit emission, indicating the “on-state”, while in the basic condition, the emission is totally quenched, indicating the “off-state”. Similarly, when the temperature is lowered, the emission intensity and lifetime are enhanced, demonstrating the on-state, while increase of temperature leads to quenching of the emission intensity and lifetime, designated as the off-state. In both cases, the process is reversible. The bathochromic shift of the spectral band together with the emission quenching and lowering of the Ru3+/Ru2+ potential is also observed upon deprotonation at elevated pH. In addition, systematic variation of the absorption spectral behaviors upon variation of pH helps in evaluation of the pK a’s of the complexes. In essence, the complexes can act as switches emanated from a huge change in their absorption, emission, and redox behaviors as a function of their acidity/basicity (pH) and temperature. Moreover, their emission spectral responses as a function of pH and temperature were utilized for the fabrication of two-input binary logic gates. Density-functional theory (DFT) and time-dependent density-functional theory (TD-DFT) computations are performed for appropriate interpretation of the spectral bands.

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