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This work reports a sustainable approach for fabrication of a highly cost-effective and operation-convenient adsorbent derived from dextran and its valorization to a metallopolymer photocatalyst. The hydrogel with a significant magnitude of equilibrium water absorbency (EWA) was prepared by crosslinking with hexamethylene diisocyanate in a simple one pot synthesis. Due to numerous functionalities, the hydrogel not only adsorbs cationic and anionic dyes but also efficiently scavenges heavy and valuable metal ions from effluents. The removal efficiency of dyes (concentration 100 mg L−1) is greater than 80% in the presence of 100 mg of adsorbent. The adsorption process and its probable mechanism are supported by both experimental (via appropriate analytical characterization) and theoretical (kinetic modelling and thermodynamic calculations) evidence. The recovery of heavy metals was demonstrated with silver ions, which were further readily reduced to silver nanoparticles to generate a metallopolymer photocatalyst. The latter catalyzes complete reduction of nitrophenol within 10 seconds in the presence of sunlight. A process flow diagram for commercial scale up and production of an economically viable adsorbent for effluent treatment using waste from the sugar industry and its valorization as a photocatalyst is reported for the first time.

In order to study the less understood anti-tumor mechanism of pyrazolone based mixed ligand complexes, four Cu(II) mixed ligand complexes [Cu(L1)(Phen)NO3] (1), [Cu(L2)(Bipy)NO3] (2), [Cu(L2)(Phen)NO3] (3) and [Cu(L2)(Bipy)NO3] (4) [L1 = 3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazole-4-carbaldehyde; L2 = 4-(1-naphthoyl)-3-methyl-1-(p-tolyl)-1H-pyrazol-5(4H)-one] have been synthesized and fully characterized. Single crystal X-ray diffraction analysis of three complexes indicated mononuclear structures exhibiting square pyramidal geometries. The inhibitory effects of the complexes on the cell population growth of the human lung carcinoma (A549) and human lung epithelial cell lines (L132) were determined by MTT assay, DAPI staining and DCFDA staining, which assessed mitochondrial dysfunction, nuclear condensation and intracellular oxidative stress, respectively. The expression levels of Bax (pro-apoptotic) and BCl2 (anti-apoptotic) genes were also studied in A549 cells wherein, both genes showed moderate downregulation after treatment with all the test complexes.

A series of oxovanadium(IV) complexes of 4-acylpyrazolone ligands were synthesized and characterized by elemental analyses, FT-IR, UV-Vis, EPR spectroscopy and single crystal XRD. The single-crystal X-ray analysis of the complex VO(L1)2 shows that the ligands were coordinated with the vanadium atom in a twisted form to create a distorted octahedral geometry and two O,O-chelating acylpyrazolonate ligands constitute two six-membered rings with the vanadium atom. The catalytic activity of all the complexes was evaluated for the oxidation of benzylic alcohols with H2O2 as an oxidant. The conditions for maximum conversion as well as selectivity for the desired product were optimized by varying different parameters such as the molar ratio of substrate to H2O2, the amount of the catalyst, reaction time and solvent. A possible pathway for the oxidation of benzylic alcohols was also proposed on the basis of the spectral evidence.