Top PDF Structural Studies of Diethylphenylphosphonite-Transition Metal Complexes

Structural Studies of Diethylphenylphosphonite-Transition Metal Complexes

Structural Studies of Diethylphenylphosphonite-Transition Metal Complexes

It fonns li gands which can behave similarly to the aminesp and yet 9 with an increa s e in the electronegativity of its substituents j a phosphorus ligand can resemble carbon monoxide i[r]

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THERMAL AND ANTIMICROBIAL STUDIES OF SOME BENZILIC ACID - AMINO ACID TRANSITION METAL COMPLEXES

THERMAL AND ANTIMICROBIAL STUDIES OF SOME BENZILIC ACID - AMINO ACID TRANSITION METAL COMPLEXES

The use of Amino acid transition metal complexes as antimicrobial agents has been reported recently. During the past decades, much importance has been given to the synthesis of new transition metal complexes and the evaluation of these agents for their antibacterial and antifungal activity. In the last few years so many studies has been done on the structure and chemical behavior of several metal complexes to find out an alternative against the antimicrobial drugs. This study emphasis special interest to the discovery of the new metal complexes possesses antibacterial and antifungal activity. A survey of literature has indicated that no work has been done on Cu (II), Ni (II), Mn (II) and Co (II) complexes of benzilic acid and amino acid hence the same was undertaken and findings are reported in the present paper. The physicochemical investigation on the bivalent metal complexes was carried out by conductometric, magnetic and spectral techniques with the object to compare their properties. Alanine is an alpha-amino acid encoded by the genetic code. It occurs in bacterial cell walls and in some peptide antibiotics and is an intermediate in sugar metabolism, cause higher blood pressure in human when present in large quantity. Rhizoctonia solani is a soil born plant pathogen cause plant diseases like collar rot. Phytophthora capsici is a plant pathogen that causes foot rot of peppers and Colletotrichum gloeosporioides is a fungus which attacks fruits, ornamental plants etc.
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Transition metal terpyridine complexes for molecular electronics

Transition metal terpyridine complexes for molecular electronics

Functionalised terpyridine units are of interest for use in molecular electronics but have not been extensively studied. As a terpyridine unit has three nitrogen atoms it is able to act as a tridentate ligand, Figure 2.2. Functionalisation of the terpyridine ligand can also be easily achieved making them an ideal ligand to use in transition metal complex single molecule conductance measurements. There have been extensive successful studies into terpyridine as a complexing ligand for various transition metal ions. The common geometry of the bisterpyridine complexes is a distorted octahedral geometry, because the most common connectivity for the transition metal ion is hexacoordinate.
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Transition metal complexes of an isatinic quinolyl hydrazone

Transition metal complexes of an isatinic quinolyl hydrazone

without O- bridging (complexes 1, 3 and 8) or with O- bridging (complex 2). In case of complexes 4, 6 and 7, the hydrazone behaves as dianionic NNO tridentate with or without O- bridging. However, the latter mode of bonding is not observed in our previous study for a similar isatinic hydrazone; 3-[2-(4,8-dimethylquinolin-2-yl)hydrazono] indolin-2-one [10]. This is due to the presence of the Me- group in the 8- position in close proximity to the hetero- cyclic N- atom of the quinoline ring [6]. Hence, the degree of basicity and deprotonation of the hydrazone as well as the mode of bonding are highly affected by the position of the Me- group. The dimeric complexes (2 and 7) have the trans arrangement and are formed via lactim bridging, whereas the binuclear complex (8) is formed via chloride bridging. Characterization of the obtained complexes was achieved via elemental analyses, magnetic and conductivity measurements as well as spectral studies.
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Synthesis and Physio-Chemical Studies on Some Antimicrobial Schiff Bases and Their Transition Metal Complexes

Synthesis and Physio-Chemical Studies on Some Antimicrobial Schiff Bases and Their Transition Metal Complexes

assignable to υ C=S group appeared unchanged in the IR spectra of the complexes excluding the possiblility of coordination through sulphur atom. Thus the ligand is behaving in tetradentate manner. The ligand N,N’-dimethyl-4-amino bunzaldehyde thiocarbohydrazone has behaved in tri-dentate manner as indicated by IR spectra. The bands due υ C=N and υ C=S group have been shifted to lower positions suggesting involvement of these groups in coordination. This ligand is therfore behaving in tridentate manner.

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Synthesis, biological evaluation and corrosion inhibition studies of transition metal complexes of Schiff base

Synthesis, biological evaluation and corrosion inhibition studies of transition metal complexes of Schiff base

Background: The transition metal complexes formed from Schiff base is regarded as leading molecules in medicinal chemistry. Because of the preparative availability and diversity in the structure of central group, the transition met- als are important in coordination chemistry. In the present work, we have designed and prepared Schiff base and its metal complexes (MC 1 –MC 4 ) and screened them for antimicrobial, anticancer and corrosion inhibitory properties. Methodology: The synthesized metal complexes were characterized by physicochemical and spectral investigation (UV, IR, 1 H and 13 C-NMR) and were further evaluated for their antimicrobial (tube dilution) and anticancer (SRB assay)
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Synthesis, structural characterization and biological activity of transition metal complexes of schiff base ligand furan derivatives

Synthesis, structural characterization and biological activity of transition metal complexes of schiff base ligand furan derivatives

Thermogravimetric analyses (TGA and DrTA) of the Schiff base ligand and its chelates are used to : (i) get information about the thermal stability of these new complexes, (ii) decide whether the water molecules (if present) are inside or outside the inner coordination sphere of the central metal ion, and (iii) suggest a general scheme for thermal decomposition of these chelates. In the present investigation, heating rates were suitably controlled at 10 0 C min -1 under nitrogen atmosphere, and the weight loss was measured from the ambient temperature up to ≅ 1000 0 C. The data are provided in Table-4. The weight loss for each chelate was calculated within the corresponding temperature ranges. The TGA curve of Schiff base ligand exhibits a first estimated mass loss of 49.93% (calcd: 50.76%) at 30-400 0 C, which may be attributed to the liberation of C 8 H 6 O 2 as gases. In the 3 rd and 4 th stages within
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Synthesis, compositional and spectral studies of some transition metal complexes with 3-aminolawsonoxime

Synthesis, compositional and spectral studies of some transition metal complexes with 3-aminolawsonoxime

Now a days there has been growing interest in the structural study of the complexes derived from organic compounds containing oxygen and nitrogen donors with antimicrobial activity. Quinones are the naturally occurring materials in soil plants 2 and animals 3 . It has important role in many biological electron transfer processes. In these processes they are reversibly reduced while divalent metal centers are oxidized. The derivative of quinone, lawsone (2

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Studies of transition metal nitrite complexes

Studies of transition metal nitrite complexes

These calculations have been used to derive ecr and e1t parameters for the nitrite ligands, and the parameters are shown to be transferable not only to other complexes with the same tran[r]

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Biological Activity Of Transition Metal Complexes Of 4- Formylpyridine Thiosemicarbazone; Equilibrium Studies

Biological Activity Of Transition Metal Complexes Of 4- Formylpyridine Thiosemicarbazone; Equilibrium Studies

, 1993). However, an increase in frequency of complex 1 may be attributed to back bonding from metal to and υ(C=S) in the ligand shifted to lower frequency or found missing in the complexes suggesting the coordination of thiol or thiolate sulphur (Beraldo et al, 2001; From the Far IR region of the spectra, N), υ(M-S), υ(M-Cl) ) bands in the complexes. Analysis of IR spectral data (table 1) shows that the ligand is bidentate with azomethine nitrogen and thione/thiolate sulphur as potential donor sites forming five membered chelates with the metal
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In vitro antioxidant, antimicrobial and larvicidal studies of schiff base transition metal complexes

In vitro antioxidant, antimicrobial and larvicidal studies of schiff base transition metal complexes

Modified antibacterial test was performed using the agar well diffusion method. The microorganisms were inoculated on Muller Hinton Agar and spread uniformly using sterile spreader in Petri plates. Three wells of 6 mm in diameter were made on Muller Hinton Agar using a sterile well puncher. The cut agar blocks were carefully removed by the use of forceps sterilized by flaming. 50 µL and 100 µL of the freshly prepared solution of metal complex (1 mg/mL) in DMSO were poured into two wells and negative control DMSO is poured in one well and the plates were allowed to stand for 1 h at room temperature for the diffusion of the substances and before the growth of organism commenced, the plates were incubated at 37 °C for 4 h. Antimicrobial activity was determined by measuring the diameter of zones showing complete inhibition.
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Synthesis, spectral and antimicrobial studies of tetraazamacrocyclic complexes of bivalent transition metal ions of bioinorganic relevance

Synthesis, spectral and antimicrobial studies of tetraazamacrocyclic complexes of bivalent transition metal ions of bioinorganic relevance

The purity and formation were ascertained by determining the melting points of recrystallized samples on electrothermal melting temperature apparatus in open capillaries, by running single spot on TLC and carbon, hydrogen and nitrogen analyses (Reported in Table 1) carried out by micro analytical technique on Elemental Analyser Euro-E 3000. Infrared spectra were recorded in the range of 4000-400 cm -1 on ʻ Bruker spectrophometer’ by using KBr pellets. 1 H- NMR spectra of the synthesized dihydrazide was recorded in acetone solvent on NMR spectrophotometer Bruker DRX 300(MHz FT- NMR with low and high temperature facility (-90ºC to +80ºC) and electronic spectra of complexes were recorded on Lab-India UV-Visible spectrophotometer UV 3000 + in DMSO at room temperature. The magnetic susceptibilities were measured at room temperature on a Gouy balance using CuSO 4 .5H 2 O as calibrant.
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Studies on DNA Cleavage and Antimicrobial screening of Transition Metal complexes of 4-aminoantipyrine Schiff base

Studies on DNA Cleavage and Antimicrobial screening of Transition Metal complexes of 4-aminoantipyrine Schiff base

FT IR spectra: The IR spectra of the complexes are compared with that of the free ligand to determine the changes that have taken place during the complexation. All data are listed in table-2. IR spectrum exhibit a strong band at 1645 cm -1 which is characteristic of the azomethine group (C=N) in the free Schiff base. In IR spectra of complexes, this band shifts to lower frequency of 1588-1560 cm -1 which indicates that the azomethine nitrogen is one of the coordinating atoms in the Schiff base 35-37 . All complexes and ligand show band in the region 1014-1069 cm -1 and 756-758 cm -1 can be assigned to phenyl ring vibration. The IR broad band of metal complexes in the range of 3111-3470 cm -1 indicate the presence of coordinated water molecule 38, 39 in the metal complexes. The spectra of the metal complexes also show some new bands in the region of 435-428 cm -1 and 581-598 cm -1 which are probably due to the formation of M-N and M-O bonds respectively 40, 41 . Two bands were observed at 1644-1651 cm -1 and 1301-1371 cm -1 assigned to ν assy coo - and ν sy coo - in complex 42 .
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 SYNTHESIS AND BIOCHEMICAL STUDIES OF TRANSITION METAL COMPLEXES OF ISATIN N(4)-METHYL(PHENYL)THIOSEMICARBAZONE

 SYNTHESIS AND BIOCHEMICAL STUDIES OF TRANSITION METAL COMPLEXES OF ISATIN N(4)-METHYL(PHENYL)THIOSEMICARBAZONE

Thus, the results obtained from antimicrobial activity of the synthesized derivatives show that the complexes are more active towards various organisms than the ligand. Such a mode of higher biological activities of the complexes may be due to the effect of metal ion in the chelated form that disturbs the normal cell process. This in turn, prevents the protein synthesis thereby, inhibiting the further growth of the organisms. The exact biochemical means by which the complexes exhibit increased activity is not truly apparent, but possibly be explained on the origin of Tweedy’s chelation theory and Overtone’s concept 18,19 .
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ONE POT SYNTHESIS OF PIPERIDONE BASED TRANSITION METAL COMPLEXES AND THEIR ANTIOXIDANT AND ANTIFUNGAL ACTIVITY STUDIES

ONE POT SYNTHESIS OF PIPERIDONE BASED TRANSITION METAL COMPLEXES AND THEIR ANTIOXIDANT AND ANTIFUNGAL ACTIVITY STUDIES

In this research article, we have synthesized a new piperidone ligand and its metal complexes. The formation of the compounds has been confirmed by the analytical data, IR, electronic, mass, 1 H NMR spectral studies, magnetic susceptibility, and molar conductance data. The above studies reveal that the piperidone ligand acts as neutral tridentate coordinating through nitrogen and hydroxyl oxygen atoms to the metal ions. The results displayed that Ru (M 7 (BHP)) and Co (M 3 (BHP)) complexes exhibit higher antioxidant activity and complexes
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Ternary transition metal complexes of tridentate (ONO) Schiff base: Synthesis, spectroscopic and biological studies

Ternary transition metal complexes of tridentate (ONO) Schiff base: Synthesis, spectroscopic and biological studies

Ternary Schiff base transition metal complexes have been synthesized and characterized by physico-chemical and spectral techniques. The lower molar conductance value indicates that all the complexes are non-electrolytes. Based on FTIR spectra the coordinating mode of the ligands was confirmed. Based on the spectral studies square planer geometry has been proposed. All the metal complexes exhibited significant activities against the microbes under

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SYNTHESIS, SPECTRAL STUDIES AND ANTIMICROBIAL SCREENING OF SOME TRANSITION METAL COMPLEXES WITH SUBSTITUTED ACETOPHENONE THIOSEMICARBAZONE

SYNTHESIS, SPECTRAL STUDIES AND ANTIMICROBIAL SCREENING OF SOME TRANSITION METAL COMPLEXES WITH SUBSTITUTED ACETOPHENONE THIOSEMICARBAZONE

All compounds have been characterized on the basis of spectral (IR, NMR) studies and elemental analysis. IR spectra (400-4000cm-1) were recorded using a KBr. Central drug research institute (CDRI), Lucknow and Department Of Chemistry, University of Rajasthan, Jaipur. 1H NMR spectra were recorded on Brucker spectrometer (300 MHz) at CDRI, Lucknow using CDCl 3 /DMSO as solvent.

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Synthetic and Structural Studies of Some Bivalent Transition Metal Complexes with Oxygen and Nitrogen Containing Schiff Base

Synthetic and Structural Studies of Some Bivalent Transition Metal Complexes with Oxygen and Nitrogen Containing Schiff Base

The present communication deals with the result of the Schiff base ligand 3-amino 2 ethyl quinazoline 4(3H) Semicarbazone (AEQS) with bivalent transition metal ions, Cu(II), Co(II) and Ni(II). The ligand and its metal complexes are characterized on the basis of molar mass, elemental analyses, IR, electronic spectra, molar conductivity, magnetic moment measurement. The reaction of the ligand with Cu(II), Co(II) and Ni(II) resulted in the formation of the complexes have the general composition [M(AEQS) 2 ]X 2 where M= Cu(II), Co(II) and Ni(II). AEQS=3-amino 2 ethyl quinazoline 4(3H) semicarbazone and X = Cl - , Br - or I - . The studies proposes a distorted octahedral
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Synthesis and Spectral Studies of Some Transition metal Complexes

Synthesis and Spectral Studies of Some Transition metal Complexes

The complexes are stable in air except those of Ti(III) & V (III) and are non hygroscopic. These are insoluble in water and common organic solvents, but soluble in DMF, DMSO and acetonitrile. The analytical data suggested 1:1 metal : ligand stoichiometr y for the complexes. The molar conductance values of the complexes suggested 1:3 electrolytic nature for trivalent metal ion & 1: 2 for divalent metal ion complexes.

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Reactivity and structural studies of metal complexes bound to DNA

Reactivity and structural studies of metal complexes bound to DNA

Comparisons with Other Studies. As described previously, Geise and co- workers have recently reported a limited study of the effect of intervening mismatches on long-range guanine oxidation (10), and they concluded that any attenuation in long-range oxidation arose from a competition between trapping of a guanine radical at the mismatch site versus hole transport; at a guanine-containing mismatch, the guanine radical would be more accessible and, hence, easier to trap. The oxidant used as well as assemblies in which charge transport is measured differ from those described here, and that may lead to some differences between the two systems with respect to relative yields. Nonetheless, the proposed explanation of Geise and co-workers for attenuation of yield in the presence of intervening mismatches is clearly invalid here. It is evident from the results that mismatches that do not contain guanines, in fact, lead to the largest attenuation in the yield of long-range guanine oxidation. Guanine-containing mismatches instead cause at most only small perturbations in long-range charge transport. Therefore, competitive hole trapping at the mismatch site does not appear to be a key factor governing the efficiency of electron transport. Solvent accessibility is clearly, however, a more
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