Monika Swami

Microwave-assisted synthesis, characterization and biological activities of organotin (IV) complexes with some thio Schiff bases

Microwave-assisted synthesis and characterization of the organotin (IV) complexes are reported. Trigonal bipyramidal and octahedral complexes of tin (IV) have been synthesized by the reaction of dimethyltin (IV) dichloride with 4-nitrobenzanilide-S-benzyldithiocarbazate (L(1)H), 4-chlorobenzanilide-S-benzyldithiocarbazate (L(2)H), 4-nitrobenzanilidebenzothiazoline (L(3)H) and 4-chlorobenzanilidebenzothiazoline (L(4)H). The complexes so formed were characterized by elemental analysis, conductance measurements, molecular weight determinations and spectral data viz. IR, UV-Visible, (1)H and (13)C NMR. The anti-microbial activities of the ligands and their corresponding organotin (IV) complexes have been screened against various strains of bacteria and fungi. Antifertility activity against male albino rats has also been reported.

Microwave synthesis, spectral studies, antimicrobial approach, and coordination behavior of antimony(III) and bismuth(III) compounds with benzothiazoline

The reaction of 2-hydroxy-N-phenylbenzamide with 2-aminobenzenethiol yielded 2-hydroxy-N-phenylbenzamidebenzothiazoline (H2-Saly · BTZ/HO⋂N⋂SH). The reaction of H2-Saly · BTZ with PhSbCl2, SbCl3, and BiCl3 under varied reaction conditions (microwave, as well as conventional method) gave corresponding antimony( III) and bismuth(III) Schiff base compounds (substitution along with addition) in different coordination environments. These complexes were characterized by elemental analysis, IR and NMR (1H and 13C) spectral studies. The ligand was found to bifunctional tridentate, as well as monodentate for different starting materials of metal (Sb/Bi), as well as for different reaction conditions, hence, suitable coordination environments and pseudotrigonal bipyramidal geometry for the antimony and bismuth complexes have been proposed. Their biological activities have also been checked against many fungi and bacteria. The complexes were found to be more toxic than the corresponding ligand. The article is published in the original.

Coordination chemistry of palladium(II) and platinum(II) complexes with bioactive Schiff bases: Synthetic, spectral, and biocidal aspects

The Schiff bases, 5-nitro-indol-2,3-dionehydrazinecarboxamide (HSCZ1) and 7-nitro-indol-2,3- dionehydrazinecarboxamide (HSCZ2), have been synthesized by the condensation of 5-nitro-indol-2,3-dione and 7-nitro-1H-indol-2,3-dione with semicarbazide hydrochloride, respectively. The palladium(II) and platinum( II) complexes have been prepared by mixing palladium chloride and platinum chloride in 1: 2 molar ratios with monobasic bidentate Schiff bases. The ligands and complexes of palladium and platinum have been characterized by elemental analyses, melting point determinations, conductance measurements, molecular weight determinations, and IR, 1H NMR, and UV spectral studies. These studies showed that the ligands coordinate to the metal atoms in a monobasic bidentate mode, coordinating through oxygen and nitrogen donor systems. Thus, a tetracoordinated environment around the metal atom has been proposed. Both the ligands and their complexes have been screened for their biological activity on several pathogenic fungi and bacteria and were found to possess appreciable fungicidal and bactericidal properties. Plant growth regulating activity of one of the ligands and its complexes has also been recorded on gram plant, and results have been discussed.

Sulfur-Bonded Coordination Compounds of Palladium(II) and Platinum(II) and Their Antimicrobial Activity

The synthetic, spectroscopic, and biological studies of some new palladium(II) and platinum(II) complexes derived from biologically active sulfur donor ligands 1H-indol-2,3-dione benzothiazoline (Bzt 1 H) and 5-nitro-1H-indol-2,3-dione benzothiazoline (Bzt 2 H) have been described. The reactions were carried out in 1:2 molar ratios. The authenticity of the benzothiazolines and their complexes has been established on the basis of elemental analyses; molecular weight determinations; and IR, 1 H NMR, 13 C NMR, and UV spectral studies. Based on IR and 1 H NMR spectral studies, a square-planar structure has been assigned to these complexes. Studies were conducted to assess the comparative growth inhibiting potential of the synthesized complexes against the benzothiazolines for a variety of fungal and bacterial strains. The studies demonstrate that the ligands and complexes possess antimicrobial properties. Further, it was noted that the growth-inhibiting potential of the complexes is greater than the parent benzothiazolines.

Sulfur-Bonded Organogermanium (IV) Complexes of Biopotent Bases and Their Antiandrogen and Biocidal Properties

In the search for the better fungicides, bactericides and antiandrogen agents, studies have been carried out to assess the growth-inhibiting potential of the newly synthesized organogermanium(IV) complexes against various pathogenic fungal and bacterial strains as well as on reproductive organs of the male albino rats. The results of these studies have been compared with the standard fungicide Bavistin and bactericide Streptomycin. The studies demonstrate that the ligands and their trimethylgermanium(IV) complexes have comparable antimicrobial activity. The results also indicated that the weights of the body and vital organs were not affected after the treatment suggesting that the complexes have no side effect or toxicological effect and maintained normal physiology of the animals throughout the experiment. It has also been revealed that the organogermanium(IV) complexes showed more antifertility effect than the bases. These complexes were synthesized by the reactions of trimethylgermanium(IV) chloride with biologically potent N∪SH donor bases and characterized by elemental analyses, conductance measurements, molecular weight determinations and IR, 1 H NMR, 13 C NMR and electronic spectral studies.

In Vitro Antibacterial and Antifungal Activities of Some Sulfur–Nitrogen–Oxygen and Oxygen–Nitrogen–Oxygen Donor Bifunctional Tridentate Schiff Bases and Their Boron(III) Complexes

Antimicrobial properties of sulfur, nitrogen, and oxygen bonded organoboron (III) complexes with biologically potent ligands viz., 2-hydroxy-N-phenyl benzamide hydrazine carboxamide(HO∩N∩OH), 2-hydroxy-N-phenyl benzamide hydrazine carbothioamide (HO∩N∩SH), and 2-hydroxy-N-phenyl benzamide hydrazine carbodithioic acid (HO∩N∩SH), have been studied. The unimolar and bimolar reactions of triisopropoxy borane with dibasic tridentate ligands resulted in the formation of colored solids, which have been characterized by elemental analysis, molecular weight determinations, and conductance measurements. The UV, IR, and NMR (1H, 13C, and 11B) spectral studies indicate a tetra-coordinated geometry for the resulting complexes. The ligands and their complexes have been screened for their fungicidal and bactericidal activities, and the results indicate that they exhibit significant antimicrobial properties. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Synthesis, Spectroscopic Characterization, and In Vitro Antimicrobial Potency of Sulfur-Bonded Complexes of Boron(III)

The present article describes the synthesis and characterization of tetracoordinated boron (III) complexes with monobasic bidentate ligands (L 1 H, L 2 H, L 3 H, L 4 H, L 5 H, and L 6 H) having the general formulae PhB(L)(OH) and PhB(L) 2 . The 1:1 and 1:2 reactions of phenyl boronic acid with monobasic bidentate ligands resulted in the formation of colored solids. The complexes have been characterized by elemental analysis, molecular weight determinations, and IR and NMR ( 1 H, 13 C and 11 B) spectroscopy, as well as UV-vis spectral studies. Based on these studies, a tetrahedral geometry has been proposed for the resulting complexes. The ligands, along with their complexes, have been screened in vitro against a number of pathogenic fungal and bacterial strains. The studies indicate that the boron chelates are more potent than the parent ligands.

Microwave-Assisted Synthesis, and Stereochemical and Biological Aspects of Some Antimony(III) and Bismuth(III) Complexes with Biologically Potent Bidentate Schiff Bases

Tetra- and pentacoordinated antimony and bismuth derivatives have been prepared by the interactions of monophenylantimonydichloride(III), trichlorostibane, and trichlorobismuthane with the sodium salts of 3-(indolin-2-one)hydrazinecarbothioamide (L1H) and 3-(indolin-2-one)hydrazinecarboxamide (L2H), under microwave irradiation as well as by conventional heating. These compounds were further characterized by analytical and spectroscopic techniques including UV, IR, 1H NMR, and 13C NMR spectra. Newly synthesized complexes with their corresponding ligands were also tested for their antifungal and antibacterial activities.

Antimicrobial, antifertility, and antiradiation studies of Ga(III) and Tl(I) complexes with N∩S and N ∩ O donor systems

New complexes of gallium(III) and thallium(I) derived from 5,6-dimethyl-1H-indol-2,3-dione hydrazinecarbothioamide (L1H) and 5,6-dimethyl-1H-indol-2,3-dione hydrazinecarboxamide (L2H) have been prepared and investigated using a combination of microanalytical analysis, melting point, molar conductance measurement, electronic, IR, 1H NMR, and 13C NMR spectral studies. Gallium isopropoxide interacts with the ligands in 1 : 1, 1 : 2, and 1 : 3 molar ratios resulting in the formation of colored products, whereas TlCl forms only unimolar products. The mono- and bis-alkoxy derivatives are dimeric, while the tris ligand metal complexes are monomeric. On the basis of conductance and spectral evidences, a pentacoordinate structure for gallium(III) 1 : 1 complexes, hexacoordinate structure for 1 : 2 and 1 : 3 complexes, and a bicoordinate geometry for thallium(I) complexes have been assigned. The ligands are coordinated to gallium(III) and thallium(I) via the azomethine nitrogen and the thiolic sulfur/enolic oxygen. The antimicrobial activities of the ligands and complexes have been screened in vitro against bacteria Pseudomonas cepacicola and Bacillus subtilis and fungi Collectatrichum capsici and Fusarium oxysporum. The complexes have higher activities than the free bases. In vivo studies of the ligands and their corresponding complexes have also been carried out to assess their antifertility and antiradiation activities. The results of these activities indicate the antiandrogenic and radiation protective nature of these complexes.

Organoboron(III) and organolead(IV) complexes as antimicrobial and antimycobacterial agents: Synthetic, structural, and biological aspects

Phenylboron(III) and triorganolead(IV) derivatives of the types PhB(OH)(DTCZ), PhB(DTCZ)2, and Ph3Pb(DTCZ) (where DTCZ− is the anion of a S-benzyldithiocarbazate ligand) have been synthesized by the substitution reactions of phenylboronic acid and triphenyllead chloride with S-benzyldithiocarbazate. The resulting complexes have been characterized by elemental analyses, molecular weight determinations, and conductivity measurements. The mode of bonding has been established on the basis of infrared and 1H, 13C, and 11B NMR spectroscopic studies. Probable tetrahedral and trigonal bipyramidal structures for the resulting derivatives have been proposed. The X-ray powder diffraction study of the compound [PhB(OH)(L1)] was carried out in order to have an idea about the molecular symmetry of the compound. The results show that the compound belongs to the orthorhombic crystal system. In the quest for better fungicides and bactericides, the studies were conducted to assess the growth inhibiting potential of the synthesized complexes against various fungal and bacterial strains. The studies demonstrate the concentration reached levels which are sufficient to inhibit and kill the pathogens. The antimycobacterial effects of the organolead(IV) compounds were also examined. The results obtained indicated that the compounds display antimycobacterial activity.