Arsenic induced cleavage of the spirolactam ring of a cleft shaped electronically enriched rhodamine based chemoreceptor molecule 3′,6′-bis­(ethylamino)-2-((2-hydroxy-5-methylbenzylidene)­amino)-2′,7′-dimethylspiro­[isoindoline-1,9′-xanthen]-3-one (PBCMERI-23) has been reported in the present work. The developed easy, instant and economic luminescent probe instigate toward unlocking the selectivity for a specific lethal water contaminant such as As­(III) from aqueous media up to a level of 0.164 ppb (beyond the critical limit of the World Health Organization). PBCMERI-23 displays a 2-fold optical response (chromogenic, colorless to reddish pink; fluorogenic, non-blooming fluorescence to yellow emission) via the ring opening phenomenon of the developed chemoreceptor. Owing to the remarkable photophysical and structural properties of the synthesized probe, the recognition event has been turned on in the low energy region. Detailed experimental techniques further supported by theoretical evidence establishes the plausible mechanistic course of the host:guest interaction. The spectrophotometric response of the developed chemoreceptor PBCMERI-23 turns out to be reversible with incremental addition of a stoichiometric amount of I–. The optical recognition phenomenon has been further synchronized and interfaced with molecular logic gate to molecular electronics. To explicate the bioapplicability of PBCMERI-23, varying cell lines, viz., pollen grains of Allamanda puberula (Aapocynaceae), radiator plant (Peperomia pellucida), Poecilia reticulata, Danio rerio, and squamous epithelial cells have been monitored. The probe displays sparkling yellow illumination when the cells were visualized under fluorescence microscope, which confirms its cell permeability and is a biomarker toward intracellular investigation and bio-imaging of As­(III). Furthermore, the chemoreceptor has enormous capability in detecting As­(III) from a series of wastewater specimens with varying pH, which makes the present chemoreceptor PBCMERI-23 unique of its kind.

Herein, a hydrazine-based chromogenic, fluorogenic and electrochemical chemosensor BCC [1,5-bis(4-cyanophenyl) carbonohydrazide] was reported.

A dual-channel chromogenic and fluorogenic fused-aromatic-system-based chemoreceptor (2-(benzo[d]thiazol-2-yl)-1-((pyren-8-yl)methylene)hydrazine) (TyM) was designed for ditopic sensitivity towards heavy and transition metal ions (HTMs), such as Cu, in an aqueous medium and lethal CN in a semi-aqueous medium. The chemoreceptor displayed proclivity towards the targeted analytes with a distinct optical response (yellow to colourless in the case of Cu and yellow to bright red for CN). TyM formed a 2 : 1 adduct with Cu with a detection limit of 40 nM. A 1 : 1 binding stoichiometry was confirmed with the chemoreceptor TyM with CN in sub-nano molar limit of detection. In addition to sophisticated spectroscopic analysis, such as UV-vis, fluorescence, FTIR, H-NMR,C-NMR, ESI-MS, and HRMS, the plausible mechanistic course of sensing was also established from a theoretical perspective. The reversible UV-vis response of the chemoreceptor TyM towards CN and H can mimic different molecular logic functions and therefore can be exploited for designing several complex electronic circuits principally based on Boolean Algebra. In vitro fluorescence imaging in male microspores of seed plants (Bohonia Nigalandra) and Monilia Albicans (diploid fungus) with TyM and Cu confirmed the permeability of the chemoreceptor TyM at the cellular level as well as its ability to investigate transition metals, such as Cu, in biological samples.

A general synthesis of both acridines and acridinium ions is descried from inexpensive and commercially available aliphatic starting materials using iron as catalyst and aerobic oxygen as oxidant in alcoholic solvent to produce water as only by product.

Quinolin-2(1H)-ones are prevalent in natural products and pharmacologically useful compounds. Here we present an unconventional and hitherto unknown photocatalytic approach to their synthesis from easily available quinoline-N-oxides.

Aromatic CÀ O bond is ubiquitous in natural product and pharmaceuticals, and their formation have significant importance in organic synthesis. A mild atom-economic visible-light photocatalytic approach has been developed for single-step synthesis of diverse aryl alcohols, ethers and esters through direct CÀ H functionalization of aromatic ring at ambient condition. This approach uses DDQ as photocatalyst and TBN as co-catalyst to facilitate the substitution of aromatic CÀ H by neutral nucleophile oxygen of water, alcohols and carboxylic acids and it uses aerobic oxygen as the terminal oxidant to produce water as the only by-product.

A urea-based molecule behaving as a ditopic sensor for fluoride and cadmium.

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