Indian Association for the Cultivation of Science

About: Indian Association for the Cultivation of Science is a education organization based out in Kolkata, India. It is known for research contribution in the topics: Excited state & Catalysis. The organization has 3867 authors who have published 10457 publications receiving 220098 citations.

A family of mononuclear molybdenum-(VI), and -(IV) oxo complexes with a tridentate (ONO) ligand

Abstract: The salicylhydrazone of anthranilhydrazide (H2L) reacted with MoO2(acac)2 in refluxing alcohols to yield compounds of the general formula MoO2L(ROH) (where R = CH3, C2H5, n-C3H7, n-C4H9). The complex MoO2L(C2H5OH) is found to undergo facile reaction with heterocyclic bases to form MoO2L(Q)-type complexes where Q = pyridine, 4-picoline, imidazole and substituted imidazoles. Single crystal X-ray structural studies on the ligand H2L (1) and the complexes MoO2L(C2H5OH) (2) and MoO2L(Imz) (3) indicate that the free ligand exists in its keto form, but in the two complexes 2 and 3 the ligand coordinates to the MoO22+ core through the enolate oxygen, the phenolate oxygen and the azomethine nitrogen. Reaction of MoO2L(C2H5OH) with PPh3 in CH3CN under dry dinitrogen, in the absence and presence of bipy, produced MoIVOL (2a) (brown) and MoIVOL(bipy) (2b) (green) respectively along with Ph3PO. This reaction is reminiscent of the oxotransfer reaction from the MoO2+2 core of a molybdoenzyme to the substrate PPh3. Complexes 2 and 3 crystallized in the P21/n and P21/c space groups respectively and for both of them Z = 4. The structures clearly show that 2 and 3 have distorted octahedral coordination environments in which the Mo–O(ethanol) bond of 2 and the Mo–N (imidazole) bond of 3 are significantly longer than is usually observed. This is indicative of the weak bonding of ethanol and imidazole to the MoO22+ core and points to the inherent weakness of the sixth coordination position of the coordination polyhedron of the MoO22+ core in MoO2L(C2H5OH) and MoO2L(Imz).

Folic Acid-Polyaniline Hybrid Hydrogel for Adsorption/Reduction of Chromium (VI) and Selective Adsorption of Anionic Dye from Water

Abstract: A porous 3D folic acid(F)-polyaniline(PANI) hybrid hydrogel (F-PANI), produced by in situ polymerization of aniline, exhibit highest compressive stress(15.1 kPa), 3D hierarchical network morphology with BET surface area 236 m2/g. Here PANI is present in emeraldine salt(ES) state which facilitates excellent adsorption of anionic pollutants. It exhibits an extremely high adsorption capacity for Cr(VI) and during adsorption Cr(VI) is reduced to Cr(III).The electrical impedance spectra of the Cr(VI) adsorbed xerogel, support the conversion of PANI chains from ES to pernigraniline base(PB) making the xerogel more resistive. It also selectively adsorbs anionic dyes, the adsorption capacity increases with decrease of pH. Both the adsorption data are found to be well explained through pseudo-second-order kinetic model and they obey Langmuir adsorption isotherm. F-PANI2 showed high adsorption capacities selectively towards anionic pollutants e.g. Cr(VI), eosine yellow, rose bengal, methyl orange and low adsorption...