Veenu Mishra

Fabrication of innovative ZnO nanoflowers showing drastic biological activity

The present study deals with the synthesis of ZnO nanoflowers (ZnO-1 and ZnO-2) at room temperature using new structurally characterized single molecular precursors (1 and 2). 1, 2 and ZnO-1 were explored for their potential to reduce the viability of the Gram-negative bacteria Escherichia coli.1 and 2 were found to be promising antibacterial agents, while the ZnO nanoflowers demonstrated a relatively non-toxic nature. 1, 2 and ZnO-1 were further evaluated for DNA binding and cleavage behaviour. 1 and 2 showed strong binding affinity towards CT-DNA compared to ZnO-1. In addition, all the three compounds demonstrated oxidative cleavage of pBluescript plasmid DNA in the presence of H2O2.

Reduction of selective polyaromatic nitrotriptycene via an azoxytriptycene intermediate under ambient conditions using a cobalt/cobalt oxide nanocomposite (CoNC)

A cobalt-based nanocomposite (CoNC) has been prepared from a recently reported single source molecular precursor (SSMP) [CoII(hep-H)(H2O)4]SO4 (A) (hep-H = 2-(2-hydroxylethyl)pyridine). The resulting nanocomposite material was characterized by using various physicochemical techniques such as XRD, SEM, EDAX, TEM and XPS spectroscopy. X-ray diffraction patterns show the weakly crystalline nature of the catalyst. This was also confirmed by the SAED pattern obtained from HR-TEM. XPS analysis reveals the formation of metallic cobalt and the cobalt oxide (CoO) nanocomposite. CoNC was employed for the facile catalytic hydrogenation of 2-nitrotriptycene (M1) and 2,6,14-trinitrotriptycene (M2) as model substrates under atmospheric reaction conditions, which otherwise takes place either with RANEY® Nickel, Pd/C or SnCl2/HCl catalysts under harsh conditions. The mechanistic pathway reveals that the reduction of M1 proceeds via the intermediacy of azoxy triptycene (III) and N-hydroxylamine triptycene (IV).

Isolation of a Metastable Intermediate in a Heterometallic CuII–HgII 1D Polymeric Chain: Synthesis, Crystal Structure, and Photophysical Properties

A metastable heterometallic intermediate, [Cu2(bpy)2(DIPSA)2Hg2(OAc)4(DIPSA)2]n (1, where OAc = CH3COO(-), bpy = bipyridine, and DIPSA = diisopropylsalicylic acid), has been isolated and characterized during the synthesis of 1D polymer [Cu2(bpy)2(DIPSA)2(CH3CN)2Hg2(OAc)2(DIPSA)4]n (2) at ambient temperature in acetonitrile. Moreover, recrystallization of 2 in methanol results in monomeric [Cu(DIPSA)(bpy)(CH3OH)]·CH3OH (3). Complexes 1-3 have been characterized by elemental analysis, Fourier transform infrared, and UV-vis spectroscopy as well as by their single-crystal X-ray structures. The photophysical study suggests the quenching of fluorescence of DIPSA upon complexation.

Bis[2-(2-hy-droxy-meth-yl)pyridine-κ(2)N,O](pivalato-κO)copper(II).

The structure of the centrosymmetric title complex, [Cu(C5H9O2)2(C6H7NO)2], has the CuII atom on a centre of inversion. The CuII atom is six-coordinate with a distorted octahedral geometry, defined by the N and O atoms of the chelating 2-(2-hydroxymethyl)pyridine ligands and two carboxylate O atoms from two monodentate pivalate ions. The crystal packing is stabilized by intermolecular C—H⋯O and intramolecular O—H⋯O hydrogen-bond interactions.

Thiophene-containing thiolato dimers, oxygen inserted Cu(II) complex, crystal structures, molecular docking and theoretical studies

Abstract Reactions of n-butyl- and n-octyl-thiophene with CS2 at 0 °C resulted in thiolate dimers 1 and 2, respectively. The reaction of 1 with Cu(NO3)2·3H2O in methanol under ambient reaction conditions yielded monomeric [CuII{(n-C4H9(C4H2S)CS2O}2] (3). 1 and 3 were authenticated by their single-crystal X-ray crystal structures. Crystal structure of 3 revealed cleavage of the S-S bond of 1 followed by insertion of O-atom, forming a new five-membered Cu–O–S–C–S metallacycle. 1, 2, and 3 were further investigated for their bioactivity through molecular docking with nine different proteins having medicinal implications. Molecular docking of 1, 2 and 3 revealed considerable interaction with different proteins viz. cancer protein Tankyrase 2, influenza viral protein Polymerase subunit PAC–PB1N complex (H5N1), Polymerase subunit PA endonuclease (H1N1), Polymerase subunit PAn Apo(avian influenza), and FTSZ (Bacillus subtilis). Comparatively, 1 has promising application in therapeutics as compared to 2 and 3 based on its inhibitory constant and binding energy. Density functional theory calculations were performed to better understand the bonding of complex using MO diagram in 1–3. Moreover, TDDFT calculations were performed to facilitate the assignment of electronic transitions of UV–Vis spectra.