Anand Pariyar

Fluorescence signaling systems for sensing Hg(II) ion derived from A2B-corroles

Selective detection of Hg(II) ions in solution by a series of novel free base bis-(nitrophenyl) corroles (1-4) with general formula A(2)B (where A = nitrophenyl, and B = N,N-dimethylaminophenyl, thienyl, naphthyl and tridecyloxyphenyl group) is described. Among the free base corroles, 4, with a tridecyloxy long chain moiety, has been found to exhibit the highest Hg(II) sensing ability. The detection is based on the fluorescence quenching of the corroles, arising from the combined effect of static (coordination) and dynamic (exciplex formation) factors.

Switching closed-shell to open-shell phenalenyl: toward designing electroactive materials.

Open-shell phenalenyl chemistry started more than half a century back, and the first solid-state phenalenyl radical was realized only 15 years ago highlighting the synthetic challenges associated in stabilizing carbon-based radical chemistry, though it has great promise as building blocks for molecular electronics and multifunctional materials. Alternatively, stable closed-shell phenalenyl has tremendous potential as it can be utilized to create an in situ open-shell state by external spin injection. In the present study, we have designed a closed-shell phenalenyl-based iron(III) complex, Fe(III)(PLY)3 (PLY-H = 9-hydroxyphenalenone) displaying an excellent electrocatalytic property as cathode material for one compartment membraneless H2O2 fuel cell. The power density output of Fe(III)(PLY)3 is nearly 15-fold higher than the structurally related model compound Fe(III)(acac)3 (acac = acetylacetonate) and nearly 140-fold higher than an earlier reported mononuclear Fe(III) complex, Fe(III)(Pc)Cl (Pc = pthalocyaninate), highlighting the role of switchable closed-shell phenalenyl moiety for electron-transfer process in designing electroactive materials.

A non-heme cationic Fe(III)-complex intercalated in montmorillonite K-10: synthesis, characterization and catalytic alkane hydroxylation with H2O2 at room temperature

A non-heme iron complex cis-[FeIII(cyclam)Cl2]Cl (cyclam = 1,4,8,11-tetraazacyclotetradecane) has been intercalated into smectite montmorillonite K-10. The intercalated solid has been characterized using EDXRF, AAS, TGA, PXRD, IR and UV-visible analyses. The heterogeneous iron(III)–cyclam has been found to be capable of hydroxylating C–H bonds as strong as those in cyclohexane (BDE = 99.7 kcal mol−1) using benign H2O2 at room temperature. The reactivity of the heterogeneous catalytic system is found to significantly improve in comparison with that of cis-[FeIII(cyclam)Cl2]Cl/H2O2 under homogeneous conditions. The catalytic reactions are marked by a very high selectivity for alcohols which is comparable with the best known non-heme catalysts with H2O2. The results critically reflect the role of the clay matrix surrounding the cationic metal complex in tuning the catalytic activity and selectivity of alkane hydroxylation.