"STUDIES OF SOME NEW COORDINATION COMPOUNDS OF PLATINUM, PALLADIUM, SILICON, GERMANIUM, TIN AND LEAD WITH BIOLOGICALLY ACTIVE AZOMETHINES" INTRODUCTION (original) (raw)
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A novel Schiff base ligand N-(4-phenylthiazol-2yl)-2-((2-thiaxo-1,2-dihydroquinolin-3-yl)methylene)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 2-thioxo-1,2-dihydroquinoline-3- carbaldehyde and its newly synthesized Cu(II), Co(II), Ni(II), and Zn(II) complexes have been characterized by elemental analysis and various spectral studies like FT-IR, 1H NMR, ESI mass, UV-Visible, ESR, TGA/DTA, and powder X-ray diffraction studies. The Schiff base ligand (L) behaves as tridentate ONS donor and forms the complexes of type [ML(Cl)2] with square pyramidal geometry. The Schiff base ligand (L) and its metal complexes have been screened in vitro for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method.The DNA cleavage activity of ligand and its metal complexes were studied using plasmid DNA pBR322 as a target molecule by gel electrophoresis method.The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties for the ligand and its metal complexes against Artemia salina. The results showed that the biological activities of the ligand were found to be increased on complexation.
Cytotoxic Activity of Schiff Bases and their Complexes
Schiff Base in Organic, Inorganic and Physical Chemistry [Working Title]
Various organic chelating agents have many applications in treating the several diseases and they act as antibacterial, antiviral, antimalarial and cytotoxic agents. Among the organic chelating agents thiosemicarbazones and their derivatives play a unique role in various fields of medicine. Thiosemicarbazones and their derivatives find a numerous applications and among them cytotoxic activity occupies a major portion due to the severity of the cancer treatment. In this present chapter we described and discussed the cytotoxic activity of thiosemicarbazones, their derivatives and various metal complexes of them. For this purpose, we reviewed the research articles published in various reputed international journals since 35 years. We summarized the results of those research findings and it is found that among the various metal ions, mostly the platinum and palladium complexes are effective cytotoxic agents than other metal complexes.
2010
Schiff bases are the compounds having azomethine (-C=N-) group which are easily synthesized by condensation of primary amine with active carbonyl group. Schiff bases made an important group of ligands having a number of donor atoms possessing fascinating mode of linkage with a variety of metals. Nitrogen atom of azomethine group having the lone pair of electron in its sp 2 hybridized orbital is considered responsible for the chemical and biological properties, as reported by several studies, therefore, Schiff bases form the major class of compounds in several fields, like medicinal, pharmaceutical, analytical, organic reagents and in various other industries [1-7]. Schiff bases emerged as an important part in the growth of coordination chemistry, which proved that they placed a great role for the progress in inorganic biochemistry also. It is evident from literature that the complexation of metals particularly transition metals with Schiff bases increases their biological properties. Schiff bases of biguanide had also been widely studied due to their broad biological spectrum and wide therapeutic applications like anticancerous, antimalarial and anti-infective. Mumtaz et al. [8] synthesize the novel Schiff bases of transition metal complexes using condensation between sulphadizine and 2-carboxybenzaldehyde and their antimicrobial activity was Synthesis, Characterization and Biological Studies of Novel Schiff Base viz. Bis-1,1'-(pyridine-2,6-diyldieth-1-yl-1-ylidene) biguanidine and Their Transition Metal Complexes
Applied Sciences
Metal complexes play an essential role in pharmaceutical sciences for their multiple and important activities. Schiff bases are versatile pharmacophores able to form chelating complexes with several metals in different oxidation states. Complexes with Schiff bases are widely described in the literature for their multiple actions and numerous advantages, such as low cost and easy synthesis. They show multiple biological activities, including antimicrobial, antioxidant, antimalarial, antinflammatory and antitumor. Schiff bases may also form complexes with lanthanides and actinides acting as catalysts (e.g., in various synthetic processes) and antitumor agents. This review intends to extend on our previous paper regarding Schiff bases as antitumorals, highlighting the importance, in the field of the anticancer agents, of these tools as ligands of metal complexes.
Journal of the Serbian Chemical Society, 2011
Using a bidentate ligand, a Schiff base of 5-acetamido-1,3,4- thiadiazole-2-sulphonamide, complexes of transition metals having the general formula ML2, where M = Mn(II), Fe(II), Ni(II) and Cu(II), were synthesized. The complexes were characterized by elemental analysis, molar conductivity, magnetic moment, electronic, ESR and IR spectroscopy, and particle size analysis. The conductivity data of the complexes suggests their non-electrolytic nature. The stability constants and free energy change for the complexes were calculated. Spectral studies and magnetic susceptibility measurements revealed an octahedral geometry for all the complexes. The ligand and its complexes were screened for their fungicidal activity against Aspergillus niger and A. flavus.
Oriental Journal of Chemistry
The study includes preparation and characterisation of mixed azo-linked Schiff-base and DTCs ligands and their complexes. The starting material was isolated from the mixing of naphthyl amine diazonium salt with 2-aminophenolein a 1:1 mole ratio in water. In this work, the formation of azo-linked Schiff-base and DTCs ligands are reported. Ligand of the azo-linked Schiff-base was achieved by the reaction of starting material with 4-(dimethylamino)benzaldehyde) (HL 1). The DTCs was isolated by the reaction of (C 6 H 5) 2 NH with carbon disulphide in potassium hydroxide (L 2). The complexes were prepared by mixing the azo-linked Schiff-base ligand and DTCs ligand with the metal salts; Co II , Ni II , Zn II and Cd II in a 1:1:1 mole ratio. Ligands and complexes were characterised by analytical and spectroscopic analyses including; microanalysis, chloride content, thermal analysis, magnetic susceptibility for complexes, conductance, FTIR, UV-Vis and 1 H-NMR spectroscopy. Physico-chemical techniques indicated complexes demonstrated four and six coordinate structures in the solid and solution state. Biological activity of the ligands and their metal complexes were screened for their antimicrobial activity against four bacterial species (Escherichia coli and Enterobacter Gram-ve, (Bacillus stubtilis and Staphylococcus aureus Garam + ve.
J Inorg Biochem, 1999
The reaction of [ReOCl 3 (PPh 3 ) 2 ] with N, N-bis(2-mercaptoethyl)benzylamine and 4bromobenzenethiol allowed for the isolation of [ReO{η 3 -(SCH 2 CH 2 ) 2 N(CH 2 C 6 H 5 )}-(η 1 -C 6 H 4 Br-4-S)] (1). The reaction of [ReOCl 3 (PPh 3 ) 2 ] with [(HSCH 2 CH 2 ) 2 N(CH 2 C 5 H 4 N)] and the appropriate thiol in chloroform treated with triethylamine has led to the isolation of a series of neutral rhenium complexes of the type [ReO{η 3 -(SCH 2 CH 2 ) 2 N(CH 2 C 5 H 4 N)}(η 1 -C 6 H 4 X-4-S)] (X = Br (2), Cl (3), F (4), and OCH 3 (5)) and [ReO{η 3 -(SCH 2 CH 2 ) 2 N(CH 2 C 5 H 4 N)}(η 1 -C 6 H 4 OCH 3 -4-CH 2 S)] (6). Likewise, under similar reaction conditions, the use of the related tridentate ligand, [(HSCH 2 CH 2 ) 2 N(CH 2 CH 2 C 5 H 4 N)], has led to the isolation of a series of rhenium complexes of the type [ReO{η 3 -(SCH 2 CH 2 ) 2 N(CH 2 CH 2 C 5 H 4 N)}(η 1 -C 6 H 4 X-4-S)] (X=Br , Cl (8), OCH 3 (9)), as well as [ReO{η 3 -(SCH 2 CH 2 ) 2 N(CH 2 CH 2 C 5 H 4 N)}(η 1 -C 6 H 4 Cl-4-CH 2 S)]·0.5CH 3 (CH 2 ) 4 CH 3 (10). These compounds are extensions of the '3+1' approach to the synthesis of materials with the {MO} 3+ core (M=Tc and Re), which have applications in nuclear medicine. The ligands chosen allow systematic exploration of the consequences of para-substitution on the monodentate thiolate ligand [S] and of derivatization of the substituent R on the tridentate aminodithiol ligand [SNS] of the type (HSCH 2 CH 2 ) 2 NR. Such modifications can influence lipophilicity, charge, size and molecular weight of the complex and consequently the biodistribution.
1999
The reaction of [ReOCl 3 (PPh 3 ) 2 ] with N, N-bis(2-mercaptoethyl)benzylamine and 4bromobenzenethiol allowed for the isolation of [ReO{η 3 -(SCH 2 CH 2 ) 2 N(CH 2 C 6 H 5 )}-(η 1 -C 6 H 4 Br-4-S)] (1). The reaction of [ReOCl 3 (PPh 3 ) 2 ] with [(HSCH 2 CH 2 ) 2 N(CH 2 C 5 H 4 N)] and the appropriate thiol in chloroform treated with triethylamine has led to the isolation of a series of neutral rhenium complexes of the type [ReO{η 3 -(SCH 2 CH 2 ) 2 N(CH 2 C 5 H 4 N)}(η 1 -C 6 H 4 X-4-S)] (X = Br (2), Cl (3), F (4), and OCH 3 (5)) and [ReO{η 3 -(SCH 2 CH 2 ) 2 N(CH 2 C 5 H 4 N)}(η 1 -C 6 H 4 OCH 3 -4-CH 2 S)] (6). Likewise, under similar reaction conditions, the use of the related tridentate ligand, [(HSCH 2 CH 2 ) 2 N(CH 2 CH 2 C 5 H 4 N)], has led to the isolation of a series of rhenium complexes of the type [ReO{η 3 -(SCH 2 CH 2 ) 2 N(CH 2 CH 2 C 5 H 4 N)}(η 1 -C 6 H 4 X-4-S)] (X=Br , Cl (8), OCH 3 (9)), as well as [ReO{η 3 -(SCH 2 CH 2 ) 2 N(CH 2 CH 2 C 5 H 4 N)}(η 1 -C 6 H 4 Cl-4-CH 2 S)]·0.5CH 3 (CH 2 ) 4 CH 3 (10). These compounds are extensions of the '3+1' approach to the synthesis of materials with the {MO} 3+ core (M=Tc and Re), which have applications in nuclear medicine. The ligands chosen allow systematic exploration of the consequences of para-substitution on the monodentate thiolate ligand [S] and of derivatization of the substituent R on the tridentate aminodithiol ligand [SNS] of the type (HSCH 2 CH 2 ) 2 NR. Such modifications can influence lipophilicity, charge, size and molecular weight of the complex and consequently the biodistribution.
Iranian Journal of Science and Technology, Transactions A: Science, 2017
New isatinic hydrazone Schiff-base ligands, namely furan-2-carboxylic acid (2-oxo-1,2-dihydro-indol-3-ylidene)-hydrazide (L 1), thiophene-2-carboxylic acid (2oxo-1,2-dihydro-indol-3-ylidene)-hydrazide (L 2) and 2-(pyridine-2-yl-hydrazono)-1,2-dihydro-indol-3-one) (L 3) are reported. The ligands were prepared by the condensation of furan-2-carboxylic acid hydrazide (L 1), thiophene-2-carboxylic acid hydrazide (L 2), and 2-hydrazino pyridine (L 3) with isatine. Monomeric complexes were prepared from the reaction of the corresponding metal chloride with the ligands. The ligands and their nine new complexes of the general formulae [M(L n) 2 ]Cl 2 [where M = Co(II), Zn(II) and Cd(II); n = L 1 , L 2 and L 3 ] were characterised by spectroscopic methods (FTIR, UV-Vis, 1 H, 13 C NMR), elemental analysis, metal content, magnetic measurement and molar conductance. These studies revealed the formation of six coordinate complexes, in which the geometry about metal atom is a distorted octahedral. Biological activity of the ligands and their metal complexes against Gram-positive bacterial strain Bacillus (G ?) and Gramnegative bacteria Ecoli (G-) are evaluated. The effects of prepared compounds depend on the type of tested bacteria. It is clear that the ligands and their metal complexes have a potential effect on the Gram-positive (G ?) and Gramnegative (G-) strains of the tested bacteria.