scholarly journals Biological and Spectral Studies of Newly Synthesized Triazole Schiff Bases and Their Si(IV), Sn(IV) Complexes

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Kiran Singh ◽  
Parvesh Puri ◽  
Yogender Kumar ◽  
Chetan Sharma ◽  
Kamal Rai Aneja

The Schiff bases HL1-3have been prepared by the reaction of 5-bromothiophene-2-carboxaldehyde with 4-amino-5-mercapto-3-methyl/propyl/isopropyl-s-triazole, respectively. Organosilicon(IV) and organotin(IV) complexes of formulae (CH3)2MCl(L1-3), (CH3)2M(L1-3)2were synthesized from the reaction of (CH3)2MCl2and the Schiff bases in 1 : 1 and 1 : 2 molar ratio, where and Sn. The synthesized Schiff bases and their metal complexes have been characterized with the aid of various physicochemical techniques like elemental analyses, molar conductance, UV, IR,1H,13C,29Si, and119Sn NMR spectroscopy. Based on these studies, the trigonal bipyramidal and octahedral geometries have been proposed for these complexes. The ligands and their metal complexes have been screenedin vitroagainst some bacteria and fungi.

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Kiran Singh ◽  
Parvesh Puri ◽  
Yogender Kumar ◽  
Chetan Sharma

This paper deals with the syntheses and structural features of some new diorganosilicon(IV) and diorganotin(IV) complexes having general formulae (CH3)2MCl(L1), (CH3)2MCl(L2), (CH3)2M(L1)2, and (CH3)2M(L2)2 with new Schiff bases (M = Si and Sn). The Schiff bases HL1 and HL2 have been derived from the condensation of 3-bromobenzaldehyde with 4-amino-3-ethyl-5-mercapto-1,2,4-triazole and 4-amino-5-mercapto-3-propyl-1,2,4-triazole, respectively. The compounds have been characterized by the elemental analyses, molar conductance, and spectral (UV, IR, 1H, 13C, 29Si, and 119Sn NMR) studies. The resulting complexes have been proposed to have trigonal bipyramidal and octahedral geometries. In vitro antimicrobial activities of the compounds have been carried out.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Har Lal Singh ◽  
Jangbhadur Singh

New series of organotin(IV) complexes and Schiff bases derived from amino acids have been designed and synthesized from condensation of1H-indole-2,3-dione, 5-chloro-1H-indole-2,3-dione, andα-amino acids (phenylalanine, isoleucine, and glycine). All compounds are characterized by elemental analyses, molar conductance measurements, and molecular weight determinations. Bonding of these complexes is discussed in terms of their UV-visible, infrared, and nuclear magnetic resonance (1H,13C, and119Sn NMR) spectral studies. The results suggest that Schiff bases behave as monobasic bidentate ligands and coordinate with dibutyltin(IV) in octahedral geometry according to the general formula [Bu2Sn(L)2]. Elemental analyses and NMR spectral data of the ligands with their dibutyltin(IV) complexes agree with their proposed distorted octahedral structures. Few representative compounds are tested for their in vitro antibacterial activity against Gram-positive (B. cereus,Staphylococcusspp.) and Gram-negative (E. coli,Klebsiellaspp.) bacteria. The results show that the dibutyltin complexes are more reactive with respect to their corresponding Schiff base ligands.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Har Lal Singh ◽  
Jangbhadur Singh ◽  
A. Mukherjee

The present work stems from our interest in the synthesis, characterization, and antibacterial evaluation of organosilicon(IV) complexes of a class of amino-acid-based Schiff base which have been prepared by the interaction of ethoxytrimethylsilane with the Schiff bases (N OH) in 1 : 1 molar ratio. These complexes have been characterized by elemental analysis, molar conductance, and spectroscopic studies including electronic IR and NMR (1H,13C, and29Si) spectroscopy. The analytical and spectral data suggest trigonal bipyramidal geometry around the silicon atom in the resulting complexes. The ligands and their organosilicon complexes have also been evaluated forin vitroantimicrobial activity against bacteria (Bacillus cereus,Nocardiaspp.,E. aerogenes,Escherichia coli,Klebsiellaspp., andStaphylococcusspp.). The complexes were found to be more potent as compared to the ligands.


Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 77 ◽  
Author(s):  
Hamad M. I. Hasan ◽  
Aaza I. Yahiya ◽  
Safaa S. Hassan ◽  
Mabrouk M. Salama

Adenine complexes were prepared with some of the first series transition metals in a stoichiometric ratio of 1: 2 (Mn+: L), where Mn+ = Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, and Cd2+ ions. The Complexes were characterized by the physicochemical and spectroscopic techniques as electric conductivity, metal contents, IR, UV–Visible, and molar conductance techniques. The stoichiometric ratios of the synthesized complexes were confirmed by using molar ratio method. The dissociation constant of adenine ligand was determined spectrophotometrically. Solvent effect on the electronic spectra of the adenine ligand was examined using solvents with different polarities. The biological activity of adenine ligand and its metal complexes were tested in vitro against some selected species of fungi and bacteria. The results showed a satisfactory spectrum against the tested organisms.


2007 ◽  
Vol 2007 ◽  
pp. 1-7 ◽  
Author(s):  
Sulekh Chandra ◽  
Smriti Raizada ◽  
Monika Tyagi ◽  
Archana Gautam

A series of metal complexes of Cu(II) and Ni(II) having the general composition[M(L)X2]with benzil bis(thiosemicarbazone) has been prepared and characterized by element chemical analysis, molar conductance, magnetic susceptibility measurements, and spectral (electronic, IR, EPR, mass) studies. The IR spectral data suggest the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, an octahedral geometry has been assigned for Ni(II) complexes but a tetragonal geometry for Cu(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties.


Author(s):  
Mallikarjun S. Yadawe ◽  
Shrishila N. Unki ◽  
Sangamesh A. Patil

Some lanthanum(III) complexes have been synthesized by reacting lanthanum(III) metal salt with Schiff bases derived from 3-substituted-4-amino-5-mercapto-1,2,4-triazole and glyoxal/biacetyl/benzyl. All these complexes are not soluble in common organic solvents. However sparingly soluble in DMF and DMSO. The chemical analysis of the complexes confirmed to the stoichiometry of the type La(III)LNO3·H2O. La(III)LCl·H2O and La(III)LNCS·H2O respectively. The chelation of the complexes has been proposed in the light of analytical, spectral studies. The measured molar conductance values indicate that, the complexes are non-electrolytes. The Schiff bases and their complexes have been screened for their antibacterial and antifungal activities. The results of these studies show the metal complexes to be more antibacterial and antifungal as compared to the uncomplexed coumarins.


2020 ◽  
Vol 32 (9) ◽  
pp. 2324-2328
Author(s):  
NETRA PAL SINGH ◽  
KAUSHAL KUMAR ◽  
GAJENDRA KUMAR ◽  
ANUROOP KUMAR

A series of transition metal complexes of the type [MLX2], where M = Mn(II), Fe(II), Co(II), Ni(II), X = Cl–/CH3COO– and L = Schiff base derived from 4-nitrobenzene-1,2-diamine and 5-chloroisatin have been synthesized and characterized by elemental analysis, molar conductance, IR, UV-visible, magnetic moments measurement, 1H & 13C NMR and mass spectral studies. On the basis of physico-chemical studies and spectral evaluation, an octahedral geometry have been proposed for all metal(II) complexes. The antimicrobial activity of ligand and its metal complexes have been additionally screened against bacteria and fungi. Metal(II) complexes show good activity as compared to ligand towards studied microorganisms and also metal complexes checked for their catalytic properties for benzoylation of phenol.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Har Lal Singh ◽  
J. B. Singh

New Schiff base (HL) ligand is prepared via condensation of isatins and amino acids in 1:1 molar ratio. Metal complexes are prepared and characterized by elemental analysis, molar conductance, electronic, infrared, and multinuclear magnetic resonance (1H NMR, 13C NMR, and 119Sn NMR). The analytical data showed that the ligand acts as bidentate toward metal ions via azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of metal : ligand (1 : 2) to from metal complexes (Pb(II)(L)2 and Bu2Sn(L)2, where L is the Schiff base ligands of histidine and methionine). The conductivity values between 15 and 25 Ω−1cm2 mol−1 in DMF imply the presence of nonelectrolyte species. On the basis of the above spectral studies, distorted octahedral and tetrahedral geometry have been proposed for the resulting organotin(IV) and lead(II) complexes.


2019 ◽  
Vol 31 (4) ◽  
pp. 951-959 ◽  
Author(s):  
N.K. Chaudhary ◽  
B. Guragain

A novel AMXTC2 ligand was prepared by simultaneous stirring and refluxing of an equimolar mixture of amoxicillin and thiophene-2-carbaldehyde in methanol and was further used to synthesize metal complexes by metalation with cobalt and cadmium salts, taking ligand metal ratio 2:1. They were characterized by elemental microanalysis, FT-IR, mass, UV-visible, 1H NMR, thermal analysis, magnetic moment and molar conductance measurements. The coordination sites in the ligand were verified by their comparative and extensive spectral studies. The detailed exploration of the data suggested octahedral geometry for Co-AMXTC2 and tetrahedral geometry for Cd-AMXTC2 complexes. The thermodynamic and kinetic parameters such as E*, ΔH*, ΔS* and ΔG* of various decomposition steps were calculated from TGA curves using the Coats-Redfern method. The molar conductivity data suggested non-electrolytic nature of the complexes. SEM analysis was done to observe their surface morphology. The geometry optimization of the proposed molecular structure of the complexes was achieved by running MM2 calculation in Gaussian supported Cs-ChemOffice Ultra-11 program software. The biological activities had been evaluated in vitro against E. coli, K. pneumonia, P. vulgaris and S. aureus pathogens in order to assess their antibacterial potency. The biological data revealed better growth inhibitory action of the ligand and metal complexes with bacterial pathogens.


2009 ◽  
Vol 2 (1) ◽  
pp. 114-126 ◽  
Author(s):  
Y. Prashanthi ◽  
Shiva Raj

The Schiff bases namely MIMFMA, MIMTMA and MIPMA have been prepared by reacting 3-amino-5-methyl isoxazole with 5-methyl furan-2-carboxyaldehyde, 5-methyl thiphene-2-carboxaldehyde and pyridine-2-carboxaldehyde. The Cu(II), Ni(II), Co(II), Zn(II) and VO(IV) have been prepared by reacting metal chlorides with those  Schiff bases in an alchololic medium. The complexes are electrolytes in DMSO. These have been  characterized by using elemental analysis, IR, UV-VIS, 1H, 13C, mass spectra, magnetic susceptibility, conductance measurements and thermo gravimetric studies. The complexes were found to have composition ML2. On basis of elemental and spectral studies, six coordinated geometry is assigned for these complexes. The Schiff bases act as neutral and bidentate and coordinate through the azomethine nitrogen and furfural oxygen, thiophene sulphur and pyridine nitrogen, respectively. The synthesized ligands and their metal complexes were screened against bacteria and fungi.  The activity data show that the metal complexes are more potent than the parent Schiff bases. Keywords; Schiff bases; Transition metal complexes; Spectral studies; Antimicrobial studies. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.2732                  J. Sci. Res. 2 (1), 114-126 (2010)   


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