A strategically synthesized arseno-discriminatory tetra-phenoxido hetero-trinuclear complex envisioned for the recognition of iAs and oAs from Oryza sp. and aquatic crustaceans.

A heterotrimetallic [MnII(CuII)2(C18H18N2O2)2] complex VBCMERI has been unveiled herein to monitor its synergistic propensity towards aqueous phase As3+ (iAs and oAs) detection. VBCMERI was structurally probed by numerous analytical tools like ESI-MS, FT-IR, and SCXRD. The aqueous phase selective chromogenic alteration of the sensory probe from greenish-yellow to colorless was observed owing to interaction with As3+ (cationic form, iAs). This phenomenon can be ascribed to the displacement of the Mn2+ center with As3+, which has further been experimentally validated through cyclic voltammetric titration studies, FT-IR, and ESI-MS, and theoretically corroborated with density functional theory calculations. Interestingly, aqueous phase selective turn-on fluorogenic enhancement of the sensory probe was observed upon interaction with AsO2- (anionic form, iAs) owing to the displacement of the arsenite anion with the pivalic acid group. The distinct chromogenic alteration from greenish-yellow to colorless and the fluorogenic enhancement of VBCMERI upon interaction with the respective As3+ (iAs) and AsO2- (iAs) were successfully implemented for monitoring arsenic contamination in groundwater samples and diverse types of Oryza sp. grains from the assorted arsenic-affected zones. The competitive accumulation of arsenobetaine (oAs) in the exoskeleton and muscles of aquatic crustaceans (herein, Penaeus sp.) can be distinctly differentiated based on the turn-on fluorogenic response. Based on the sensing response and competitive accumulation tendency of different forms of arsenic in different environments, arseno-adducts with VBCMERI have been theoretically modeled for corroboration with experimental findings. The VBCMERI-AsO2- adduct was also highly efficient in regenerating the VBCMERI sensor selectively in the presence of contaminants like Pb2+. This reversible behavior was further exploited to mimic a molecular-level 3-input-2-output logic gate ensemble.

Trace Level Recognition of Zn2+ and Cd2+ by Biocompatible Chemosensor inside Androecium, Diagnosis of Pick's Disease from Urine and Biomimetic ß-Cell Exocytosis.

Two chemosensors with varying substitution have been synthesized for selective detection of d10 metal ion analyte Zn2+ and Cd2+ by fluorometric method from aqueous medium at very low limit of detection. Density functional theory (DFT)-based Loewdin spin population analysis reveals that methoxy-substituted chemosensor is much stronger donor than bromo-substituted chemosensor. Eventually, bromo and methoxy substituted chemosensors are moderate and strong donor, respectively, toward selective detection of Cd2+ and Zn2+ by luminescence induced phenomenon (blue for Cd2+ and cyan for Zn2+). The mechanism of sensing could be explained by PET-CHEF-C = N isomerization-ILCT pathway. 1H NMR, ESI-MS and FT-IR has been carried out in order to explore the selective ion sensing mechanism. Intracellular detection of Zn2+ and Cd2+ has been carried out inside androecium (filament and pollens) of Tecoma Stans. Extracellular detection of Zn2+ for yeast cells represents the bio mimetic model experiments toward ß-cells exocytosis as a marker of diabetes mellitus. The unprecedented and novel feature of the present biocompatible chemosensor is its application as biosensor to detect in vivo Zn2+ from human urine specimen which could be a next generation diagnostic tool for Pick's disease.

Stepwise formation of a pentanuclear Ni4Cu heterometallic complex exhibiting a vertex-sharing defective double-cubane core and diphenoxo- and phenoxo/azide bridging groups: a magnetostructural and DFT theoretical study.

Sequential reaction of a N5O3 octadentate tripodal ligand with Ni(2+) and subsequently with Cu(2+) and azide ligand afforded the first example of a heterobridged (phenoxo/µ(1,1)-azido) pentanuclear heterometallic (Ni4Cu) compound, which exhibits a centrosymmetric vertex-sharing defective double-cubane structure. The study of the magnetic properties reveals that the compound shows ferromagnetic interaction interactions, leading to an S = 9/2 spin ground state. Density functional theory calculations on the X-ray structure and model compounds predict ferromagnetic interactions through the magnetic exchange pathways involving each couple of metal ions.