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This work aims at elucidating the mechanism of solvation of a radical ion pair (RIP) in a micro-heterogeneous binary solvent mixture using magnetically affected reaction yield (MARY) spectroscopy. For the exciplex-forming 9,10-dimethylanthracene/N,N-dimethylaniline system a comparative, composition-dependent MARY line-broadening study is undertaken in a heterogeneous (toluene/dimethylsulfoxide) and a quasi-homogenous (propyl acetate/butyronitrile) solvent mixture. The half-saturation field extrapolated to zero-quencher concentration, B(1/2), and the self-exchange rate constants are analyzed in the light of solvent dynamical properties of the mixtures and a dielectric continuum solvation model. The dependence of B(1/2) on the solvent composition is explained by cluster formation giving rise to shortened RIP lifetimes. The results are in qualitative agreement with the continuum solvation model suggesting that it could serve as a theoretical basis for quantitative modeling.

In recent years, the tunable fluorescence emissive carbon dots (CDs) enrich the efficacy and importance via the incorporation of two or more applications. Herein, we report a pyromellitic acid-based pH-responsive multicolor emissive (orange and green) manganese doped CDs. The mechanism behind the tunable fluorescence properties at high pH is proposed based upon the detailed optical and physicochemical study. The result showed that the blue shifts are highly associated with the COO moieties on the surface. Afterward, we have expanded the applications of the synthesized CDs in a white-light-emitting diode (WLED), fingerprinting, fluorescent ink, and bioimaging.