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Convenient synthesis and Raman spectral characterization of diammonium monomolybdate(VI)

2020-12-03T10:22:05Z

Title: Convenient synthesis and Raman spectral characterization of diammonium monomolybdate(VI) Authors: Morajkar, Sudesh M; Srinivasan, Bikshandarkoil R Abstract: A convenient and cost-effective method is reported for the preparation of gram quantities of an ammonium-rich Mo compound viz. diammonium monomolybdate(VI) (NH₄)₂MoO₄ (1). The process involves a thorough grinding of a commercial sample of ammonium heptamolybdate tetrahydrate (NH₄)₆[Mo₇O₂₄]·4H₂O with an excess of ammonium bicarbonate followed by thermal treatment. The facile formation of (1) is confirmed by its characteristic Raman spectrum. The use of Raman spectroscopy to distinguish between tetrahedral monomolybdate(VI) and heptamolybdate, dichromate and monochromate(VI), paratungstate and monotungstate(VI) as well as the identification of the species present in ammoniacal solutions of MO₃ (M = Cr, Mo, W) are reported. Page(s): 1760-1767

Theoretical and experimental studies of novel histidine derived Schiff base metal complexes, active towards biomedical and MCF 7 cell lines

2020-12-03T10:19:44Z

Title: Theoretical and experimental studies of novel histidine derived Schiff base metal complexes, active towards biomedical and MCF 7 cell lines Authors: Sridevi, N; Madheswari, D Abstract: Novel tri-dentate ligand-metal complexes [Mn(II), Co(II), Cu(II), Ni(II) and Zn(II) (1-5)] have been synthesized using L-histidine amino acid derived Schiff base ligand and characterized using analytical and spectral methods like UV-visible, FT-IR and ESI-MS techniques. The antioxidant studies of the Schiff base ligand and 1-5 complexes reveal that complexes exhibit significant free radical scavenging activity against the free radical DPPH. In vitro cytotoxic activity of the 1-5 complexes evaluated against the breast cancer cell lines (MCF-7), reveal that complex 3 exhibits higher cytotoxicity than any other synthesized metal complexes. The docking studies have been carried out using BSA protein and DNA biomolecules with synthesized metal complexes. Antimicrobial studies has demonstrated that Cu(II) complexes possess higher activity against both Gram positive and Gram negative bacteria as well as Fungi. Page(s): 1768-1777

Synthesis, characterization and applications of Organomecury(II) pyrrolidine-N-thiohydrazide complexes

2020-12-03T10:16:42Z

Title: Synthesis, characterization and applications of Organomecury(II) pyrrolidine-N-thiohydrazide complexes Authors: Sharma, Rama; Kaushik, N K Abstract: The complexes of organomercury(II) with pyrrolidine-N-thiohydrazide of the type RHg(L)Cl where[R=C₆H₅ (phenyl), p-ClC₆H₄ (p-chlorophenyl), p-BrC₆H₄ (p-bromophenyl), o-, p-HOC₆H_4, (o-,p-hydroxyphenyl)_, L = pyrrolidine-N-thiohydrazide, have been synthesized and characterized by elemental analysis, IR,¹H-NMR and electronic spectral analysis. Thermogravimetric and differential thermal analytical curves are used to calculate thermodynamic parameters and variations in these parameters have been correlated with complex structural parameters. All complexes were tested in vitro for their antibacterial activity against Gram-negative bacteria, namely, Escherichia coli, Zymomonas mobilis and against two pathogenic fungal strains, namely, Aspergillus niger and Cerveleria. Page(s): 1778-1784

Crystal structure of potassium hydrogen phthalate revisited

2020-12-03T10:14:45Z

Title: Crystal structure of potassium hydrogen phthalate revisited Authors: Srinivasan, Bikshandarkoil R; Dhuri, Sunder N; Narvekar, Kedar U Abstract: The present study provides new insight into the structure of potassium hydrogen phthalate 1. The single crystal X-ray structure of 1 consists of a crystallographically independent potassium cation and a unique hydrogen phthalate anion. The µ₄-heptadentate binding mode of the unique hydrogen phthalate ligand organizes the K⁺ ions into a layer resulting in a two-dimensional (2D) coordination polymer. As a result parallel chains of face-sharing {KO₇} polyhedra extending along c are formed. The parallel chains are flanked on either side by hydrogen phthalate wings and are interlinked by vertex sharing of three polyhedra to extend the connectivity along a axis. The structure of 1 is stabilised by π∙∙∙π stacking interactions. A comparative study of the structures of alkali metal hydrogen phthalates is described. Page(s): 1785-1792