Toxicological and pesticidal studies on novel bioactive sulfonamide imine organotin(IV) complexes

Toxicological, pesticidal and stereochemical aspects of organotin(IV) complexes with a sulfonamide imine ligand having an N^∩N donor system are described with the support of elemental analysis, IR, UV, ¹H NMR, ¹³C NMR and ¹¹⁹Sn NMR spectroscopy. The spectral data suggest that the ligand acts in a monobasic bidentate manner coordinating through the nitrogen atom. The complexes have been characterized on the basis of molecular weight determinations, conductivity measurements, and magnetic measurements. The isolated products are coloured solids, soluble in dimethylsulfoxide, dimethylformamide (DMF) and methanol. All the complexes are monomeric in nature, as indicated by their molecular weight determinations. Conductivity measurements in dry DMF show them to be non‐electrolytes. From the analyses of these studies the donor sites of the ligand are located and the geometries of the donor environment around the tin(IV) acceptor centres proposed. The ligand and its metal complexes are tested in vitro against a number of pathogenic fungal and bacterial strains and the findings are discussed. Emphasis has been given to the nematicidal properties. Copyright © 2003 John Wiley & Sons, Ltd.     

Organotin(IV) and organolead(IV) complexes as biocides and fertility regulators: synthetic,spectroscopic and biological studies

Biocidal, antifertility and spectroscopic aspects of organotin(IV) and organolead(IV) complexes with amino acids(L) and 2,2‐bipyridine(L′) are described with the support of elemental analysis, IR, ¹H, ¹³C, ¹¹⁹Sn and ²⁰⁷Pb NMR spectroscopy. The spectral data suggest that the ligand L acts in a monodentate and ligand L′ in a bidentate manner, coordinating through the nitrogen atoms. The complexes have been characterized on the basis of molecular weight determinations and conductivity measurements. The isolated products are coloured solids, soluble in dimethylsulfoxide (DMSO), dimethylformamide (DMF) and methanol. All the complexes are monomeric in nature, as indicated by their molecular weight determinations. Conductivity measurements in dry DMF show them to be non‐electrolytes. The complexes have been screened against a number of fungi and bacteria to assess their growth inhibiting potential. The results are positive. In addition to these studies, the complexes show good antimicrobial properties as compared with their starting materials. The testicular sperm density, sperm morphology, sperm motility, density of cauda epididymis, spermatozoa and fertility in mating trials and the biochemical parameters of the reproductive organs of rats were examined and are discussed in detail. Copyright © 2006 John Wiley & Sons, Ltd.     

SYNTHETIC,SPECTRAL AND BIOLOGICAL STUDIES OF ORGANOSILICON (IV) COMPLEXES WITH SCHIFF BASES OF SULFA DRUGS

Abstract

In the present paper synthetic and structural studies of six-coordinated Me₂Si(NN)₂ type of organosilicon(IV) complexes of Schiff bases (NN) have been described. The complexes were characterized by elemental analyses, conductance measurements, molecular weight determinations and electronic, infrared, ¹H, ¹³C and ²⁹Si NMR spectral studies. A few representative complexes were also screened for antimicrobial activity and found to be quite active in this respect.     

Synthesis and characterization of coordination compounds of organotin(IV) with nitrogen and sulfur donor ligands

The reactions of dimethyltin dichloride with nitrogen and sulfur donor ligands derived by condensation of S‐benzyldithiocarbazate with indol‐3‐carboxylaldehyde, thiophene‐2‐aldehyde and furfuraldehyde have been investigated in 1:1 and 1:2 molar ratios in anhydrous alcohol. These ligands act as mononegatively charged bidentate species and coordinate to the central tin(IV) atom through the thiosulfur by proton exchange with the azomethine nitrogen. The newly synthesized complexes have been characterized by elemental analysis, conductance measurements and molecular weight determinations. The mode of bonding and the geometry of the complexes have been suggested on the basis of infrared, electronic and ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy, and probable structures have been assigned to these complexes. A few representative ligands and their tin(IV) complexes have also been screened for their antifungal and antibacterial activities and found to be quite active in this respect. Copyright © 2001 John Wiley & Sons, Ltd.     

SYNTHESIS AND SPECTROSCOPIC STUDIES OF SOME FUNGITOXIC ORGANOLEAD(IV) COMPLEXES OF SULFUR AND NITROGEN DONOR LIGANDS

Abstract

Some organolead(IV) complexes derived from biologically active sulfur and nitrogen donor ligands have been synthesized and characterized by elemental analyses, molecular weight determinations and conductivity measurements. The trigonal bipyramidal and octahedral geometries for these complexes have been proposed on the basis of electronic, infrared and NMR (¹H and ¹³C) spectral evidences. The antifungal activity of some of the ligands and their complexes have also been evaluated against Fursarium oxysporum SCW. ex Frics f. sp. Ciceri (Pedwick) subram.     

Microwave-assisted synthesis of nitrogen-sulfur and nitrogen-oxygen donor ferrocene-containing ligands and their organotitanium(IV) and organozirconium(IV) complexes

The synthetic routes and spectroscopic studies of organotitanium(IV) and organozirconium(IV) complexes derived from azomethines, 1-acetylferrocenethiosemicarbazone (L¹H) and 1-acetylferrocenesemi-carbazone (L²H), have been carried out in 1 : 1 and 1 : 2 stoichiometric ratios. Azomethines and their complexes have been characterized by elemental analyses, conductance measurements, molecular weight determinations, and spectral studies. The electronic, IR, and ¹H NMR and ¹³C NMR spectral data indicate that azomethines act as bidentate ligands and coordinate to the metal (Ti or Zr) via nitrogen and the sulfur or oxygen atoms giving trigonal bipyramidal and octahedral geometries for the resulting complexes. All the ligands and their complexes have been screened for their biological activity on several pathogenic fungi and bacteria and were found positive in this respect. The text was submitted by the authors in English.     

Organosilicon(IV) and organotin(IV) complexes as biocides and nematicides: synthetic,spectroscopic and biological studies of N∩N donor sulfonamide imine and its chelates

A brief account is given of the synthesis and stereochemistry and the antibacterial, antifungal, nematicidal and insecticidal behaviour of organosilicon(IV) and organotin(IV) complexes of a biologically potent ligand, 2‐acetylfuransulfaguanidine. The unimolar and bimolar substitution products have been characterized by elemental analyses, conductance measurements, molecular weight determinations, and spectral studies, viz. IR, ¹H NMR, ¹³C NMR, UV, ²⁹Si NMR and ¹¹⁹Sn NMR spectra. The data support the binding of the nitrogen atom to the metal atom in R₃M(N^∩N), [R₂M(N^∩N)₂ and R₂M(N^∩N)Cl [(R = Me/Ph and M = Si(IV) and Sn(IV)] types of complex. Based on these studies, with coordination number five and six a trigonal bipyramidal and an octahedral geometry have been proposed for the resulting derivatives. The free ligand (N^∩NH) and its respective metal complexes were tested in vitro against a number of microorganisms to assess their antimicrobial properties. The results are indeed positive. In addition to these studies, the complexes also show good nematicidal and insecticidal properties. The results of these findings have been discussed in detail. Copyright © 2004 John Wiley & Sons, Ltd.     

Antimicorbial effects of newly synthesized organotin(IV) and organolead(IV) derivatives

Triorganotin(IV) and triorganolead(IV) derivatives of the types Me₃Sn(SCZ) and Ph₃Pb(SCZ) (where SCZ^? is the anion of a semicarbanzone ligand) have been synthesized by substitution reactions of trimethyltin chloride and triphenyl-lead chloride with semicarbazones derived from heterocyclic ketones. The resulting complexes have been characterized by elemental analyses, molecualr weight determinations and conductivity measurements. The mode of bonding has been established on the basis of infrared and ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopic studies. Some respresentative complexes have also been evaluated for their antimicrobial effects on different species of pathogenic fungi and bacteria; the results of these investigations have been reported in the present paper.     

Important Properties of Sulfur–Bonded Organoboron (III) Complexes with Biologically Potent Ligands

Abstract

Important properties of sulfur/oxygen and nitrogen bonded organoboron (III) complexes with biologically potent ligands viz., semicarbazone, thiosemicarbazone, and dithiocarbazate having the donor groups ONX and NS have been studied. The unimolar and bimolar reactions of phenylboronic acid with monobasic bidentate and dibasic tridentate ligands result in the formation of colored solids which have been characterized by the elemental analysis, molecular weight determinations, and conductance measurements. The UV, IR, and NMR ( ¹ H, ¹³ C, and ¹¹ B) spectral studies indicate tetracoordinated geometry for the resulting complexes. Both the ligands and their complexes have been screened for their fungicidal and bactericidal activities, and the results indicate that they exhibit significant antimicrobial properties.     

Bioactive versatile azomethine complexes of organotin(IV) and organosilicon(IV)

Diorganotin(IV) and diorganosilicon(IV) derivatives of the types R₂MCl(TSCZ) and R₂M(TSCZ)₂ (where TSCZ is the anion of a thiosemicarbazone ligand, R=Ph or Me and M=Sn or Si) have been synthesized and characterized by elemental analyses, molecular weight determinations and conductivity measurements. The mode of bonding has been established on the basis of IR and ¹H, ¹³C ²⁹Si and ¹¹⁹Sn NMR spectroscopic studies. Some of the representative complexes have also been evaluated for their antimicrobial effects on different species of pathogenic fungi and bacteria in vivoas well as in vitro.The results of these investigations are reported. © 1998 John Wiley & Sons, Ltd.     

Microwave‐assisted synthesis and insecticidal properties of biologically potent organosilicon(IV) compounds of a sulfonamide imine

Microwave‐assisted synthesis and spectroscopic studies of dimethyl‐, diphenyl‐ and triphenyl‐silicon(IV) chelates derived from the reactions of organochlorosilanes with the sodium salt of a biologically active nitrogen donor ligand N^∩NH are described. The resulting products have been isolated and characterized by elemental analyses, molecular weight determinations and conductance measurements. On the basis of electronic, infrared, ¹H, ¹³C and ²⁹Si NMR spectral studies, trigonal bipyramidal and octahedral geometries have been suggested for the resulting complexes. The biological activity of the ligand and its corresponding complexes has been examined with regard to antifungal and antibacterial activity against pathogenic fungi and bacteria, and the results are quite encouraging. All the compounds have also been found to act as nematicides and insecticides, by reducing the number of nematodes (Meloidogyne incognita) and insects (Trogoderma granarium). Copyright © 2005 John Wiley & Sons, Ltd.     

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. The article is published in the original.     

Synthetic, structural, and antimicrobial studies of organotin(IV) complexes of semicarbazone, thiosemicarbazone derived from 4-hydroxy-3-methoxybenzaldehyde

Reaction of dibutyltin dichloride, dimethyltin dichloride, and tributyltin chloride with ligands derived from thiosemicarbazone and semicarbazone leads to the formation of a new series of organotin(IV) complexes of general formula R₂SnCl₂·L and R₃SnCl·L (where L ligands derived from the condensation of thiosemicarbazide and semicarbazide with 4-hydroxy-3-methoxybenzaldehyde). The authenticity of these ligands and their metal complexes have been established on the basis of elemental analysis, conductance measurements, molecular weight determinations, infrared, ¹H NMR, ¹³C NMR, ¹¹⁹Sn NMR, and UV spectral studies. These studies showed that the ligands coordinate to the metal atom in a bidentate. An octahedral structure is proposed for the organotin(IV) complexes. The ligands and its metal complexes are screened for their antimicrobial activities against some Gram-positive and Gram-negative bacteria, and fungus. The studies demonstrated that metalation can increase the antimicrobial activity rather than the free ligands.     

Synthesis,spectral analysis,and molecular modeling of bioactive Sn(II)-complexes with oxadiazole Schiff bases

Sn(II)-complexes of seven 2-amino-5-substituted-aryl-1,3,4-oxadiazole Schiff bases have been synthesized and characterized by various physico-chemical studies. Their structures have been confirmed by elemental analyses, infrared, ¹H NMR, UV-Vis, and mass spectral studies as well as thermal decomposition. Conductance measurements in methanol show these complexes to be non-electrolytes, and the molecular weight determinations support the proposed molecular formulae. The molecular structures of the complexes have been optimized by CS Chem 3-D Ultra Molecular Modeling and Analysis Program showing tetrahedral geometry. The bio-efficacy of the complexes has been examined against the growth of bacteria (Escherichia coli and Staphylococcus aureus) and fungi (Aspergillus flavus and Candida albicans) in vitro to evaluate their anti-microbial potential.     

Antifungicidal,antibacterial and antifertility activities of biologically active heterocyclic thiosemicarbazones and their coordination complexes with the dimethylsilicon moiety

Synthetic, structural and biological aspects of trigonal-bipyramidal, Me₂Si(NS)Cl and octahedral, Me₂Si(NS)₂ types of organosilicon (IV) complexes of heterocyclic thiosemicarbazones (N? SH) have been described. The complexes were characterized by elemental analysis, molecular weight determination, conductance measurements and electronic, infrared, ¹H and ¹³C NMR spectral studies. Some ligands and their corresponding dimethylsilicon (IV) complexes have been tested for their effects on several pathogenic fungi and bacteria. Two representative complexes have also been found to act as sterilizing agents by reducing the production of sperm in male mice.     

Nano-sized, ternary oxovanadium(IV) complexes containing electron-rich oxygen-based ligands

Some mononuclear mixed-carboxylato ??-diketonato oxovanadium(IV) complexes of the general formula [VO(??-dike)(RCOO)] (where H??-dike?=?acetylacetone; benzoylacetone or dibenzoylmethane, R?=?C₁₅H₃₁ or C₁₇H₃₅) have been synthesized from VO(acac)₂ by stepwise substitutions of acetylacetonate ion with straight chain fatty acids (RCOOH) and ??-diketones in p-xylene under reflux. The substituted acetylacetone could be fractionated out with p-xylene as an azeotrope. These were characterized by elemental analyses, molecular weight determinations, spectral (electronic, infrared, ¹H NMR, EPR and powder XRD) studies, magnetic susceptibility measurements and cyclic voltammetry. Molar conductance values indicated the complexes to be non-electrolytes in nitrobenzene. Bidentate chelating nature of ??-diketonate and carboxylate ligands in the complexes was established by infrared and NMR spectra. Molecular weight determinations confirmed mononuclear nature of the complexes. The EPR spectra illustrated coupling of the unpaired electron with ⁵¹V nucleus (I?=?7/2). Cyclic voltammograms of all the complexes displayed one-step oxidation processes. The oxidation peak potential corresponded to the quasireversible one-electron oxidation process of the metal center, yielding V(V) species. Powder XRD and transmission electron microscopy (TEM) studies indicated the particles of these were lying in the nano-size range. The synthesized complexes are a new type of mixed-ligand complexes in which vanadium is having coordination number 5. A square pyramidal geometry around vanadium has been assigned in all the complexes.     

Fungicidal,bactericidal and antifertility activities of diorganosilicon(IV) complexes derived from benzothiazolines

Synthetic, structural and biological aspects of trigonal-bipyramidal, Me₂S(N—S)CI and octahedral, Me₂Si(N—S)₂ types of diorganosilicon(IV) complexes of heterocyclic benzothiazolines (N—SH) are described. The complexes were characterized by elemental analysis, molecular weight determination, conductance measurements and electronic, infrared, ¹H and ¹³C NMR spectroscopic studies. Some ligands and their corresponding dimethylsilicon(IV) complexes have been tested for their effects on several pathogenic fungi and bacteria and found to be quite active in this respect. Antifertility activity in male mice of some representative ligands and their silicon complexes was also evaluated and discussed.     

Synthesis,Spectral, and 3D Molecular Modeling of Tin(II) and Organotin(IV) Complexes of Biologically Active Schiff Bases Having Nitrogen and Sulfur Donor Ligands

Reaction of tin(II) chloride and dimethyltin dichloride with Schiff bases derived from S-benzyldithiocarbazate leads to the formation of a new series of tin(II) and organotin(IV) complexes of general formula SnCl ₂ .L and Me ₂ SnCl ₂ .L (where L = Schiff bases are derived from the condensation of S-benzyldithiocarbazate with heterocyclic aldehydes). An attempt has been made to prove the structures of the resulting complexes on the basis of elemental analysis, conductance measurements, molecular weight determinations, infrared, and multinuclear magnetic resonance ( ¹ H, ¹³ C, and ¹¹⁹ Sn NMR) spectral studies. A few representative ligands and their tin complexes have also been screened for their antibacterial and antifungal activities and found to be quite active in this respect.     

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 publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

New coordination compounds of tin(IV) with Schiff bases of dialdehyde/diketones and sulpha drugs

New tin(IV) complexes have been synthesized by the reaction of dimethyltindichloride with nitrogen donor ligands. The ligands used in these studies were condensation products of dialdehydes/diketones and sulpha drugs. Their structural studies have been carried out on the basis of elemental analyses, ultraviolet, infrared, ¹H-NMR and ¹¹⁹Sn-NMR spectral studies. The monomeric and non-electrolytic nature of these complexes has been confirmed by their molecular weight determination and conductance measurements.