Archana Chaudhary

Sol–gel synthesis of highly pure α-Al2O3 nano-rods from a new class of precursors of salicylaldehyde-modified aluminum(III) isopropoxide. Crystal and molecular structure of [Al(OC6H4CHO)3]

Reactions of aluminum isopropoxide with salicylaldehyde in 1 : 1, 1 : 2 and 1 : 3 molar ratios in anhydrous benzene yield complexes of the type [(OPri)3−nAl(OC6H4CHO)n] {where n = 1(1); n = 2 (2); n = 3 (3)}. All the products are yellow solids and are soluble in common organic solvents. They were characterized by elemental analysis, ESI-mass spectrometry, FT-IR and 1H, 13C and 27Al NMR studies. The ESI-mass spectral studies indicate dimeric nature for (1) and (2) and monomeric nature for compound (3). Crystal and molecular structures of [Al(OC6H4CHO)3] (3) suggest that salicylaldehyde ligands bind to the metal in a side-on dihapto η2-(O,O) manner, leading to the formation of a hexa-coordinated environment around the aluminum atom. Powder XRD, SEM image, and EDX analysis appear to indicate formation of nano-sized rods for precursor (3). Sol–gel hydrolysis of all the precursors Al(OPri)3, (1), (2) and (3) followed by sintering at 1100 °C yielded α-Al2O3 (a), (b), (c) and (d), respectively. The powder X-ray diffraction patterns and the SEM images of all the oxides exhibit nano-sized microcrystalline morphology for (a) and mixed platelike nano-rod morphology for (b), (c) and (d). The EDX and TEM studies of (d) also corroborate the formation of α-Al2O3. The IR spectral studies of all the oxides indicate the formation of pure α-alumina, a versatile ceramic oxide known for exhibiting a wide variety of applications in engineering and biomedical areas.

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.

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.

Synthesis and characterization of the coordination polymer [(THF)K(μ-OPri)2Al(μ-OPri)2]n

Abstract Reaction of [Al(OPri)3] with K(OPri), in 1:1 molar ratio in refluxing anhydrous tetrahydrofuran yields a polymeric complex [(THF)K(μ-OPri)2Al(μ-OPri)2]n. The complex is characterized by spectroscopic studies and single crystal X-raydiffraction analysis.