scholarly journals Synthetic, Spectroscopic and Biocidal Aspects of Heterobimetallic Complexes Comprising Platinum(II) and a Group Four or Fourteen Element

2000 ◽  
Vol 7 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Kripa Sharma ◽  
R. V. Singh

Heterobimetallic complexes with varying amines have been synthesized by the reaction of [Pt(C2H8N2)2]Cl2 with group four or fourteen organometallic dichlorides, viz., R2MCl2 and Cp2M'Cl2 in a 1:2 molar ratio in MeOH (where M=Si or Sn, M'= Ti or Zr and R=Ph or Me). These complexes have been characterized by elemental analysis, molecular weight determinations, magnetic measurements, conductance, IR, H1 NMR and electronic spectra. The spectral data suggest a square planar geometry for all the complexes. Conductivity data suggest that they behave as electrolytes. These monometallic precursors along with their complexes have been screened in vitro against a number of pathogenic fungi and bacteria to assess their growth inhibiting potential.

2000 ◽  
Vol 7 (4) ◽  
pp. 211-218 ◽  
Author(s):  
Anil Bansal ◽  
Randhir Singh ◽  
R. V. Singh

Tetraazamacrocyclie complexes of lead and palladium have been synthesized by the template process using the bis(benzil)ethylenediamine precursor. The tetradentate macrocycle (maL) reacts with PbCl2, PdCl2 and different diamines in a 1:1:1 molar ratio in methanol to give several solid complexes of the types [Pb(maL)(R)Cl2] and [Pd(maL)(R)]Cl2 (where R = 2,6-diaminopyridine or 1,2-phenylenediamine). The macrocycle and its metal complexes have been characterized by elemental analysis, molecular weight determinations, molar conductivity, IR, 1H NMR, 13C NMR, electronic, mass and electrochemical studies. The macrocyclic ligand coordinates through the four azomethine nitrogen atoms which are bridged by benzil moieties. IR spectra suggest that the pyridine nitrogen is not coordinating. The palladium complexes exhibit tetracoordinated square-planar geometry, whereas a hexacoordinated octahedral geometry is suggested for lead complexes. The macrocycle along with its complexes have been screened in vitro against a number of pathogenic fungi and bacteria to assess their growth inhibiting potential.


2020 ◽  
Vol 3 (2) ◽  
pp. 249-256
Author(s):  
Olubunmi Adewusi ◽  

Novel Schiff base 2-((E)-(1H-indol-5-ylimino)methyl)-4-nitrophenol ligand and its Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Pd(II) complexes were synthesized by the stoichiometric reactions between the metal (II) ions and ligand in molar ratio M:L (1:1). The synthesized compounds were characterized using melting point, solubility, molar conductance, room temperature magnetic susceptibility, infra-red and electronic spectroscopies. The assignments of four-coordinate tetrahedral/square planar geometries and the bidentate nature to the complexes was corroborated by IR, electronic spectroscopies, and magnetic moments. The Pd(II) complex however was assigned an octahedral geometry. The in-vitro antimicrobial studies revealed the potential of some of the compounds as antimicrobial agents. The ligand and its metal complexes exhibited good to moderate antimicrobial activity against tested bacteria with selective inactivity against P. mirabilis and P. aureginosa. Keywords: 2-((E)-(1H-indol-5-ylimino)methyl)-4-nitrophenol, magnetic susceptibility, square planar geometry, inhibitory zone.


2000 ◽  
Vol 7 (2) ◽  
pp. 105-113 ◽  
Author(s):  
Kripa Sharma ◽  
S. C. Joshi ◽  
R. V. Singh

Synthetic, spectroscopic and antimicrobial aspects of some fertility inhibitor heterobimetallic complexes have been carried out. These heterobimetallic chelates [M(C5H5N3)2M2'(R)4]Cl2 (M = Pd or Pt and M' = Si, Sn, Ti and Zr) have been successfully synthesinzed via the reaction of M(C5H7N3)2Cl2 with group four or fourteen dichlorides in 1:2 stoichiometric proportions. The products were characterized by elemental analyses, molecular weight determinations, magnetic susceptibility measurements, conductance, and IR multinuclear NMR and electronic spectral studies. A square planar geometry has been suggested for all the complexes with the help of spectral data. Conductivity data strongly suggest that chlorine atoms are ionic in nature due to which complexes behave as electrolytes. All the complexes have been evaluated for their antmicrobial effects on different species of pathogenic fungi and bacteria. The testicular sperm density, testicular sperm morphology, sperm motility, density of cauda epididymal spermatozoa and fertility in mating trails and biochemical parameters of reproductive organs have been examined and discussed.


2020 ◽  
Vol 23 (7) ◽  
pp. 611-623
Author(s):  
Ahmed A. Soliman ◽  
Fawzy A. Attaby ◽  
Othman I. Alajrawy ◽  
Azza A.A. Abou-hussein ◽  
Wolfgang Linert

Aim and Objective: Platinum (II) and platinum (IV) of pyrophosphate complexes have been prepared and characterized to discover their potential as antitumor drugs. This study was conducted to prepare and characterize new ternary platinum (II) complexes with formamidine and pyrophosphate as an antitumor candidate. Materials and Methods: The complexes have been characterized by mass, infrared, UV-Vis. spectroscopy, elemental analysis, magnetic susceptibility, thermal analyses, and theoretical calculations. They have been tested for their cytotoxicity, which was carried out using the fastcolorimetric assay for cellular growth and survival against MCF-7 (breast cancer cell line), HCT- 116 (colon carcinoma cell line), and HepG-2 (hepatocellular cancer cell line). Results: All complexes are diamagnetic, and the electronic spectral data displayed the bands due to square planar Pt(II) complexes. The optimized complexes structures (1-4) indicated a distorted square planar geometry where O-Pt-O and N-Pt-N bond angles were 82.04°-96.44°, respectively. Conclusion: The complexes showed noticeable cytotoxicity and are considered as promising antitumor candidates for further applications.


Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 119
Author(s):  
Jamal Lasri ◽  
Matti Haukka ◽  
Hessa H. Al-Rasheed ◽  
Nael Abutaha ◽  
Ayman El-Faham ◽  
...  

The square planar complex [Pd(PT)Cl(H2O)]*H2O (HPT: 6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4(1H,3H)-dione) was obtained by the reaction of 2-methoxy-4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine (MBPT) pincer ligand with PdCl2 in a molar ratio (1:1) under thermal conditions and using acetone as a solvent. The reaction proceeded via C-N cleavage of one C-N moiety that connects the pyrazole and s-triazine combined with the hydrolysis of the O-CH3 group. The reaction of the chloride salt of its higher congener (PtCl2) gave [Pt(3,5-dimethyl-1H-pyrazole)2Cl2]. The crystal structure of [Pd(PT)Cl(H2O)]*H2O complex is stabilized by inter- and intra-molecular hydrogen bonding interactions. Hirshfeld analysis revealed that the H...H (34.6%), O...H (23.6%), and Cl...H (7.8%) interactions are the major contacts in the crystal. The charges at Pd, H2O, Cl and PT are changed to 0.4995, 0.2216, −0.4294 and −0.2917 instead of +2, 0, −1 and −1, respectively, using the MPW1PW91 method. [Pd(PT)Cl(H2O)]*H2O complex has almost equal activities against MDA-MB-231 and MCF-7 cell lines with IC50 of 38.3 µg/mL.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Pan He ◽  
Kyoji Hagiwara ◽  
Hui Chong ◽  
Hsiao-hua Yu ◽  
Yoshihiro Ito

Owing to its hydrophilicity, negative charge, small size, and labile degradation by endogenous nucleases, small interfering RNA (siRNA) delivery must be achieved by a carrier system. In this study, cationic copolymers composed of low-molecular-weight polyethylenimine and polythiophenes were synthesized and evaluated as novel self-tracking siRNA delivery vectors. The concept underlying the design of these copolymers is that hydrophobicity and rigidity of polythiophenes should enhance the transport of siRNA across the cell membrane and endosomal membrane. A gel retardation assay showed that the nanosized complexes formed between the copolymers and siRNA were stable even at a molar ratio of 1 : 2. The high cellular uptake (>80%) and localization of the copolymer vectors inside the cells were easily analyzed by tracking the fluorescence of polythiophene using fluorescent microscopy and cytometry. Anin vitroluciferase knockdown (KD) assay in A549-luc cells demonstrated that the siRNA complexes with more hydrophobic copolymers achieved a higher KD efficiency of 52.8% without notable cytotoxicity, indicating protein-specific KD activity rather than solely the cytotoxicity of the materials. Our polythiophene copolymers should serve as novel, efficient, low cell toxicity, and label-free siRNA delivery systems.


2012 ◽  
Vol 9 (2) ◽  
pp. 532-544
Author(s):  
Bibhesh K. Singh ◽  
Narendar Bhojak ◽  
Anant Prakash

Cu(II), Co(II), Ni(II) and Mn(II) complexes of Schiff base derived from 2-aminophenol and pyrrole-2- carbaldehyde have been prepared. The complexes are formed by coordination of N and O atoms of the ligand. Their structures were characterized by physico-chemical and spectroscopic methods. Molecular structure of the complexes has been optimized by MM2 calculations and suggests a tetrahedral/ square planar geometry. The bio-efficacy of the ligand and their complexes has been examined against the growth of bacteriain vitroto evaluate their anti-microbial potential.


2010 ◽  
Vol 7 (1) ◽  
pp. 585-592
Author(s):  
Baghdad Science Journal

A new series of Fe (III) , Co (II) , Ni (II) and Cu (II) complexes of the Schiff base, 5 (2-hydroxy benzylidine) -2-thio ether -1, 3, 4-thiadiazole were prepared and characterized .The imine behaves as a bidentate. The nature of bonding and the stereochemistry of the complexes were deduced from metal analyses, infrared, electronic spectra,magnetic susceptibility and conductivity measurements, an octahedral geometry was suggested for all complexes except the copper complex has a square planar geometry .preliminary in vitro tests for antimicrobial activity show that all the prepared compounds except iron complex display good activity to gram positive Staphelococcus aures and gram negative Escherchia coli.


2000 ◽  
Vol 7 (5) ◽  
pp. 237-243 ◽  
Author(s):  
Kripa Sharma ◽  
S. C. Joshi ◽  
R. V. Singh

A new series of unsymmetrical macrocyclic complexes of tin(ll) has been prepared by the template process using bis(3-oxo-2-butylidene)propane-1,3-diamine as precursor. This affords a method to synthesize these complexes with various ring sizes. The tetradentate macrocyclic precursor [N4mL] reacts with SnCl2 and different diamines in a 1:1:1 molar ratio in refluxing methanol to give complexes of the type [Sn(N4mL)Cl2]. The ring expansion has been achieved by varying the diamine between the two diacetyl amino nitrogen atoms. The macrocyclic precursor and its metal complexes have been characterized on the basis of elemental analysis, molar conductance, molecular weight determinations, IR, H1 NMR,C13 NMR, Sn119 NMR and electronic spectral studies. An octahedral geometry around the metal ion is suggested for these complexes. On the basis of molecular weights and conductivity measurements, their monomeric and non-electrolytic nature has been confirmed. The precursor and complexes have been screened in vitro against a number of pathogenic fungi and bacteria to assess their growth inhibiting potential. The testicular sperm density and testicular sperm morphology, sperm motility, density of cauda epididymal spermatozoa and fertility in mating trails and biochemicals parameters of reproductive organs have been examined and discussed.


2020 ◽  
Vol 49 (21) ◽  
pp. 6945-6949
Author(s):  
Jing Su ◽  
Lei Yin ◽  
Zhongwen Ouyang ◽  
Zhenxing Wang ◽  
Wenjun Zheng

Heterobimetallic 1,2-diaza-4-phospholide chromium(ii) complexes with a near-square planar geometry behave as field-induced single-molecule magnets, as characterized by HF-EPR and magnetic measurements.


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