Triphenylantimony(V) complexes with Schiff bases

1980 ◽  
Vol 33 (12) ◽  
pp. 2749 ◽  
Author(s):  
VK Jain ◽  
R Bohra ◽  
RC Mehrotra

Twelve new octahedral complexes of the type Ph3Sb(Cl)(OC6H4CR=NR') (where R = H and R' = Me, Et, Pr, Bu, Ph and p-tolyl; R = Me and R' = Me, Bu and Bu') and Ph3Sb(OMe)-(OC6H4CR=NR')(R = H and R' = Me; R = R' = Me) have been synthesized and characterized after purification by recrystallization. The results of the i.r. and 1H n.m.r. spectra of these complexes suggest coordination of azomethine nitrogen to the antimony atom.

2009 ◽  
Vol 6 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Prashant Singh ◽  
Shanu Das ◽  
Rajesh Dhakarey

Complexes of Co(II) with two new Schiff bases TEAB [2-hydroxy-4-{[2-oxo-2-(thiophen-2-yl)ethylidene]amino}benzoic acid] and TEPC [N-[2-oxo-2-(thiophen-2-yl)ethylidene]pyridine-3-carboxamide] have been synthesized and characterized with the help of elemental analysis, magnetic, mass,1H-NMR,13C-NMR, IR and electronic spectral data. IR spectra manifest the coordination of the ligand to the metal ion through the carbonyl oxygen, azomethine nitrogen and thienyl sulphur atoms. With the help of electronic spectral data various ligand field parameters were also calculated. All these studies reveal the distorted octahedral Co(II) complexes. Synthesized compounds have also been screened against some micro organismsviz, Escherichia coli, Proteus vulgaris, Aspergillus nigerandAspergillus flavuswith the help of ‘filter paper disc’ technique. It has been observed that the antimicrobial activities of metal complexes are higher than that of the free ligand.


2020 ◽  
Vol 12 (1) ◽  
pp. 251-258
Author(s):  
S. Isyaku ◽  
H.N. Aliyu ◽  
E.C. Ozoro ◽  
T. Abubakar

Manganese(II) complexes of Schiff bases; 2-acetylthiophene-4‑phenylthiosemi-carbazone (AT-PTSC) and 2-furylmethylketone-4-phenylthiosemi-carbazone  (AF‑PTSC) derived from condensation of 2-acetylthiophene and 2-furylmethylketone (2-acetylfuran) each with 4-phenylthiosemicarbazide in (1:1 molar ratio) ethanol, have been synthesized. The Schiff bases and the Mn(II) complexes were characterized on the basis of melting point/decomposition temperature, solubility, magnetic susceptibility, infrared spectra, molar conductance measurements,  elemental and gravimetric  analyses. The Mn(II) complexes show moderate values of decomposition temperatures. The Schiff bases and the complexes were soluble in some common organic solvents. Infrared spectral data of the Schiff bases and their complexes, indicate coordination of the Schiff bases to the metal(II) ion via azomethine nitrogen. The effective magnetic moment of the Mn(II) complexes suggested an octahedral geometry. The molar conductance values of the complexes show that the complexes are electrolytes. The results of the elemental analysis of the ligands and their complexes are in good agreement with the calculated values, suggesting a 1:2 (metal-ligand) ratio. Antimicrobial screenings of the ligands and their complexes were conducted against gram-positive (Staphylococcus aureus,) and two gram-negative (Salmonella typhi, and Escherichia coli) bacteria specie. Also three fungi mainly (Candida albicans, Mucus indicus and Aspergillus flavus) were tested. The results showed that both the ligands and the complexes are active against the bacteria and the fungi specie. Keywords: Ligand, Schiff base, 4-phenylthiosemicarbazide, 2-acetylthiophene, 2-acetylfuran molar conductivity, magnetic susceptibility, elemental analysis.


2011 ◽  
Vol 8 (3) ◽  
pp. 1258-1263 ◽  
Author(s):  
A. K. Mapari ◽  
M. S. Hate ◽  
K. V. Mangaonkar

The mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) with Schiff basesN-(2-hydroxy-1-naphthylidene)-4-methylaniline (L1H) andN-(2-hydroxybenzylidene)-2,3-dimethylaniline (L2H) have been synthesized and characterized. The resulting complexes were characterized by elemental analysis, thermogravimetric analysis, magnetic moment measurements, conductivity measurements,1H NMR, IR, UV-visible and ESR spectral studies. The Schiff bases acts as bidentate monobasic ligands, coordinating through deprotonated phenolic oxygen and azomethine nitrogen atoms. The complexes are non-electrolytic in DMSO. The presence of the two coordinated water molecules in these complexes was indicated by IR spectra and thermogravimetric analysis of the complexes. From the analytical and spectral data the stoichiometry of these complexes have been found to be [M(L1)(L2)(H2O)2] {where M = Co(II) , Ni(II), Cu(II) and Zn(II)}. It is found that Co(II), Ni(II), Cu(II) and Zn(II) complexes exhibited octahedral geometry. The antimicrobial activities of ligands and their mixed ligand complexes were screened by disc diffusion method. It is found that the metal complexes have higher antimicrobial activity than the free ligand.


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)   


2020 ◽  
Vol 45 (1) ◽  
pp. 18
Author(s):  
Abidemi Iyewumi Demehin ◽  
Mary Adelaide Oladipo ◽  
Banjo Semire

Ni(II) mixed-ligand complexes of [NiLNH3] (where L= N-salicylidene-o-aminophenol (L1), N-(5-methoxysalicylidene-o-aminophenol) (L2) and N-(2-hydroxy-1-naphthalidene)-o-aminophenol) (L3) containing ONO tridentate Schiff bases and ammonia were synthesized and characterized by elemental analysis, infrared, ultraviolet-visible, proton and carbon-13 spectroscopies. Theoretical calculations were also performed on the optimized structures of the Ni(II) mixed-ligand complexes. The Infrared and ultraviolet-visible spectra of the complexes were calculated, and the results compared with the corresponding experimental spectra to augment the experimental structural identification. The elemental analysis data confirmed the formation of 1:1:1 [metal: Schiff base: ammonia] molar ratio. The NMR spectra showed that the Schiff bases coordinated to the Ni(II) ion via the two deprotonated phenolic oxygen and azomethine nitrogen atoms. The biological studies showed that the complexes exhibited higher antibacterial and antioxidant activities than the free Schiff base ligands.


2020 ◽  
Vol 12 (1) ◽  
pp. 85-92
Author(s):  
S. Isyaku ◽  
H.N. Aliyu ◽  
E.C. Ozoro ◽  
T. Abubakar

Manganese (II) complexes of Schiff bases; 2-acetylthiophene 4‑phenylthiosemi-carbazone (AT-PTSC) and 2-furylmethylketone-4-phenylthiosemi-carbazone (AF‑PTSC) derived from condensation of 2-acetylthiophene and 2-furylmethylketone (2-acetylfuran) each with 4-phenylthiosemicarbazide in (1:1 molar ratio) ethanol, have been synthesized. The Schiff bases and the Mn(II) complexes were characterized on the basis of melting point/decomposition temperature, solubility, magnetic susceptibility, infrared spectra, molar conductance measurements,  elemental and gravimetric  analyses. The Mn(II) complexes show moderate values of decomposition temperatures. The Schiff bases and the complexes were soluble in some common organic solvents. Infrared spectral data of the Schiff bases and their complexes, indicate coordination of the Schiff bases to the metal(II) ion via azomethine nitrogen. The effective magnetic moment of the Mn(II) complexes suggested an octahedral geometry. The molar conductance values of the complexes show that the complexes are electrolytes. The results of the elemental analysis of the ligands and their complexes are in good agreement with the calculated values, suggesting a 1:2 (metal-ligand) ratio. Antimicrobial screenings of the ligands and their complexes were conducted against gram-positive (Staphylococcus aureus,) and two gram-negative (Salmonella typhii, and Escherichia coli) bacteria specie. Also three fungi mainly (Candida albicans, Mucus indicus and Aspergillus flavus) were tested. The results showed that both the ligands and the complexes are active against the bacteria and the fungi specie. Keywords: Ligand, Schiff base, 4-phenylthiosemicarbazide, 2-acetylthiophene, 2-acetylfuran molar conductivity, magnetic susceptibility, elemental analysis.


2021 ◽  
Vol 66 (1) ◽  
Author(s):  
V. Gomathi ◽  
R. Selvameena

Abstract. Mn(II) complexes of Schiff bases 4-((3-ethoxy-2-hydroxybenzylidene)amino)-N-(pyridin-2-yl)benzenesulfonamide (HL2) and 4-((3-ethoxy-2-hydroxybenzylidene)amino)-N-(pyrimidin-2- yl)benzenesulfonamide (HL3) were synthesized. The Schiff bases HL2 and HL3 and their complexes were characterized by analytical, conductance, magnetic susceptibility measurements, infrared, ultraviolet-visible, thermal analysis, and EI mass techniques. The spectral data of the complexes have revealed the bidentate complexing nature of the Schiff base ligand through phenoxide ion and azomethine nitrogen atoms. The antibacterial activities of complexes were tested against gram-positive bacterial species Pseudomonas aeruginosa (NCIM 2036) and fungal species Aspergillus niger (NCIM 105) and Mucor sp.  (NCIM 108) by disc diffusion method. Keywords: Schiff bases; Mn(II) complex; antibacterial; antifungal.   Resumen. Los complejos de Mn(II) de las bases de Schiff 4-((3-etoxi-2-hidroxibencilideno)amino)-N-(piridin-2-il)bencenosulfonamida (HL2) y 4-((3-etoxi-2-hidroxibencilideno)amino)-N-(pirimidin-2- il)bencenosulfonamida (HL3) fueron sintetizados. Las bases de Schiff HL2 and HL3 y sus complejos fueron caracterizados por métodos analíticos, conductancia, susceptibilidad magnética, espectroscopia infrarroja y UV-vis, termogravimetría, y espectrometría de masas por impacto enectrónico. Los datos espectroscópicos obtenidos para los complejos corroboraron la coordinación bidentada de los ligantes de base de Schiff a través del ion fenóxido y el átomo de nitrógeno del grupo azometino. La actividad antibacterial de los complejos se evaluó contra cepas bacterianas gram-positivas Pseudomonas aeruginosa (NCIM 2036) y contra especies fúngicas Aspergillus niger (NCIM 105) y Mucor sp.  (NCIM 108) utilizando el método de difusión en disco.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Har Lal Singh ◽  
Jangbhadur Singh

New zirconium(IV) complexes were synthesized with bidentate ligands and characterized by elemental analysis, molar conductance measurements, molecular weight determinations, IR, electronic, NMR (1H and 13C), fluorescence and molecular modeling studies. All the complexes are 1 : 2 electrolytes in nature and may be formulated as [Zr(L)2Cl2] (where L is Schiff bases of amino acids and substituted isatin). The analytical data showed that the Schiff-base ligand acts as bidentate toward zirconium ion via the azomethine nitrogen and carboxylate oxygen. The conductivity values between 8.5–12.6 Ω−1, mol−1, cm2 in DMF imply the presence of nonelectrolyte species. On the basis of spectral and molecular modeling studies, the resulting complexes are proposed to have octahedral geometries.


2010 ◽  
Vol 75 (7) ◽  
pp. 917-927 ◽  
Author(s):  
Kiran Singh ◽  
Dharam Pal

Selected new organosilicon(IV) complexes having the general formula R2SiCl[L] and R2Si[L]2 were synthesized by the reactions of Me2SiCl2 with Schiff bases [5-mercapto-4-(2-pyrrolecarboxalideneamino)-s-triazole, 5-mercapto-3-methyl-4-(2-pyrrolecarboxalidene amino)-s-triazole and 3-ethyl-5-mercapto-4-(2-pyrrolecarboxalideneamino)-s-triazole] in 1:1 and 1:2 molar ratios. All of the compounds were characterized by elemental analysis, molar conductance, and IR, UV, 1H-, 13C- and metal-NMR spectral studies. All the spectral data suggest an involvement with an azomethine nitrogen in coordination to the central metal atom. With the help of above-mentioned spectral studies, penta and hexacoordinated environments around the central metal atoms in the 1:1 and 1:2 complexes, respectively, are proposed. Finally, the free ligands and their metal complexes were tested in vitro against some pathogenic bacteria and fungi to assess their antimicrobial properties.


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