scholarly journals Metal ion promoted synthesis of pentaazamacrocyclic complexes of a few first row transition metal series derived from 2,6-diaminopyridine

2005 ◽  
Vol 70 (11) ◽  
pp. 1273-1281
Author(s):  
Ali Khan ◽  
Shabana Tabassum ◽  
Nishat Begum ◽  
Poonam Chingsubam

Anew series of dichloro/dinitrato (2,6,9,13,18-pentaazacbicyclo [12.3.1]octadeca -1(18),14,16-triene) metal(II) [MLX2](M = Mn(II), Co(II), Ni(II) and Zn(II); X = Cl or NO3) and (2,6,9,13,18-pentaazacyclo[12.3.1]octadeca-1(18),14,16-triene) copper(II) dichloride/dinitrate [CuL]X2 (X = Cl or NO3) have been synthesized by the template condensation reaction of 2,6-diaminopyridine with 1,2-diaminoethane and 1,3-dibromopropane. The complexes were studied by elemental analysis, magnetic susceptibility and conductivity measurements. Various spectroscopic techniques, viz. IR, 1H-NMR, EPR, UV/Vis, were used to establish their structures. Except for the complexes of copper(II), which are square planar, all other complexes have octahedral structures.

1975 ◽  
Vol 53 (5) ◽  
pp. 633-643 ◽  
Author(s):  
D. R. Eaton ◽  
K. Zaw

A number of Ni(II) complexes of thiourea, N-methylthiourea, N,N′-dimethylthiourea, N-naphthylthiourea, N,N′-diethylthiourea, and ethylene thiourea have been studied in acetone solution by proton magnetic resonance, magnetic susceptibility measurements, and conductivity measurements. In solution these complexes have tetrahedral, square planar, and octahedral geometries. In many cases equilibria between compounds with different geometries exist. Such equilibria have been studied as a function of temperature. The factors determining the relative stability of Ni(II) compounds with different geometries are discussed. In the present series of compounds it is concluded that the charge on the metal ion has the predominant influence in determining geometry. Some qualitative results on ligand exchange rates and mechanisms are also reported.


2021 ◽  
Vol 7 (4) ◽  
pp. 748-750
Author(s):  
S. Tihile Mangesh ◽  
N. Chaudhari Gajanan

The novel transition metal ion complexes were synthesized by refluxing the ethanolic solutions of metal acetates with Schiff base in 1:2 ratios. The structure and characterization of synthesized complexes of Mn (II), Co (II), Ni (II), Cu (II) and Zn (II) with Schiff base (E)-2-((7H-purin-6-ylimino)methyl)phenol were elucidated by using 1H NMR, FT-IR and UV-Visible spectroscopic techniques. The synthesized compounds were also been screened against gram positive and gram-negative bacteria. The novel compounds were further carried out for the study of magnetic susceptibility.


2011 ◽  
Vol 7 (2) ◽  
pp. 1338-1347
Author(s):  
Tarek Ali Fahad ◽  
Shaker.A.N. AL-Jadaan

Two new heterocyclic Organmercury compounds   were prepared from the reaction of Sulfamethaxazole and Sulfadiazine with 4-acetaminophenol as a coupler and separated as solids with characteristic colors. these compounds were characterized by F.T.IR-spectroscopy 1H-NMR , Micro-elemental Analysis and UV-Vis spectroscopic techniques . The work involves a study of acid – base properties compounds at different pH values, the ionization and protonation constants were calculated. The thermal behavior of these two compounds   were investigated on the basis of thermogravimetric (TGA) and differential thermogravimetric (DTG) analyses, Thermal decomposition of these compounds is multi-stage processes.


1994 ◽  
Vol 346 ◽  
Author(s):  
Andrew B. Bocarsly ◽  
Gireesh Kumar ◽  
Marija Heibel

ABSTRACTThe reaction of a wide variety of cyanometalate complexes of the general form [M(CN)x]n- (where M= a transition metal ion) with square planar [PdCl4]2- in aqueous solution leads to the formation of linear polymers. Polymerization occurs via substitution of chloride ligands on the Pd(II) centers, by the nitrogen end of the cyanide ligand to generate extended bridging cyanide structures. Upon generation at room temperature polymer solutions of this type under go a sol-gel transition to generate robust hydrogels having water content in excess of 95%. In the case of the cyanocobaltate/tetrachloropalladate gel, pyrolysis at 900°C produces ferromagnetic Pd/Co metallic alloys having novel morphological character. Materials formed with a hydrogel having a 2:1 Pd to Co stoichiometry are found to be “sponge-like”. When placed in water, the metallic matrix swells becoming pliable and holding up to seven equivalents of water per metal site. The conductivity and magnetic properties of this material are maintained in the swollen state. Sintering of the Pd/Co hydrogel in air generates the layered oxide, PbCoO2 having a delafossite structure.


2004 ◽  
Vol 69 (12) ◽  
pp. 1053-1061 ◽  
Author(s):  
Josef Husárek ◽  
Richard Pstorek ◽  
Michal Malon ◽  
Zedenek Sindalar ◽  
Marek Pavlícek

A series of new Ni(II) dithiocarbamate compounds of the composition [NiX(cetdtc)(PR3)](X = Cl, Br, I, NCS; cetdtc = cyclohexylethyldithiocarbamate; R = phenyl, n-butyl) has been synthesized. All the isolated complexes have been characterized by elemental analysis, IR and UV/VIS spectroscopy, 31P{1H}-NMR spectroscopy, thermal analysis magnetochemical and conductivity measurements. On the basis of the results of the physico-chemical study, all complexes are diamagnetic, non-electrolytes with a square-planar NiS2PX chromophore.


2016 ◽  
Vol 13 (2) ◽  
pp. 105-114
Author(s):  
Baghdad Science Journal

New metal ion complexes were synthesized with the general formula; K[PtLCl4], [ReLCl4] and K[ML(Cl)2] where M = Pd(II), Cd(II), Zn(II) and Hg(II), from the Azo ligand (HL) [2-Hydroxy-3-((5-mercapto-1,3,4-thiadiazol-2-yl)diazenyl)-1-naphth aldehyde] (HL) the ligand was synthesized from (2-hydroxy-1-naphthaldehyde) and (5-amino-1,3,4-thiadiazole-2-thiol). The ligand and its metal complexes are characterized by phisco- chemical spectroscopic techniques (FT.IR, UV-Vis and Mass spectra, elemental analysis, molar conductivity, Atomic Absorption, Chloride contain and magnetic susceptibility). The spectral data suggest that the (HL) behaves as a bidentate ligand in all complexes. These studies revealed tetrahedral geometries for all metal complexes, except square planar for Pd(II) complex and except octahedral geometry for Pt(IV) and Re(V) complexes. The study of complexes formation via molar ratio of (M:L) as (1:1). Theoretical treatment of this ligand and its metal complexes in gas phase using Hyper chem.8 was preformed.


2011 ◽  
Vol 76 (1) ◽  
pp. 75-83 ◽  
Author(s):  
A.S. Ramasubramanian ◽  
Ramachandra Bhat ◽  
Ramakrishna Dileep ◽  
Sandya Rani

Transition metal complexes of 5-bromosalicylidene-4-amino-3- mercapto-1,2,4-triazine-5-one with metal precursors, such as Cu(II), Ni(II), Co(II) and Pd(II), were synthesized and characterized by physicochemical and spectroscopic techniques. All the complexes are of the ML type. Based on analytical, spectral data and magnetic moments, the Co(II) and Ni(II) complexes were assigned octahedral geometries, while the Cu (II) and Pd(II) complexes square planar. A study on the catalytic oxidation of benzyl alcohol, cyclohexanol, cinnamyl alcohol, 2-propanol and 2- methyl-1-propanol was performed with N-methylmorpholine-N-oxide (NMO) and molecular oxygen as co-oxidants. All the complexes and their parent organic moiety were screened for their biological activity on several pathogenic bacteria and were found to possess appreciable bactericidal properties.


2014 ◽  
Vol 79 (3) ◽  
pp. 291-302 ◽  
Author(s):  
Vukadin Leovac ◽  
Ljiljana Vojinovic-Jesic ◽  
Sonja Ivkovic ◽  
Marko Rodic ◽  
Ljiljana Jovanovic ◽  
...  

The synthesis and structural characterization of a square-planar copper(II) complex with pyridoxal S-methylisothiosemicarbazone (PLITSC) of the formula [Cu(PLITSC?H)H2O]Br?H2O (1) as the first Cu(II) complex with monoanionic form of this ligand were described. Complex 1 together with two previously synthesized complexes [Cu(PLITSC)Br2] (2) and [Cu(PLITSC)Br(MeOH)]Br (3) were characterized by elemental analysis, IR and electronic spectra and also by the methods of thermal analysis, conductometry and magnetochemistry.


1990 ◽  
Vol 68 (5) ◽  
pp. 774-781 ◽  
Author(s):  
Mohamed S. Abdel-Moez ◽  
Shaker L. Stefan ◽  
Mostafa M. El-Behairy ◽  
Mohamed M. Mashely ◽  
Basheir A. El-Shetary

The stepwise stability constants of VO(II), Mn(II), Cu(II), Ni (II), Co(II), Zn(II), Fe(III), and UO2(II) metal ions with 2-(2-acetylphenylhydrazone)-5,5-dimethyl-1,3-cyclohexane dione (2-APHDm), 3-(2-acetylphenylhydrazone)pentane-2,4-dione (2-APHA), 2-(2-acetylphenylhydrazone)-1-phenyl-1,3-butane dione (2-APHB), 2-(2-acetylphenylhydrazone)-1,3-diphenyl-1,3-propane dione (2-APHDB), and 3-(2-acetylphenylhydrazone)-1,1,1-trifluoropentane-2,4-dione (2-APHTA) were determined at 30 °C by pH titrations in 75% (v/v) dioxane–water solvent. In addition, metal complexes of three related β-diketones, 2-APHA, 2-APHB, and 2-APHDB have been synthesized and characterized by elemental analysis, uv–visible, ir spectra, and conductance in DMF and magnetic susceptibility measurements. The structure of the complexes have been proposed. Keywords: transition metal complexes of hydrazone-β-diketone ligands.


Author(s):  
Sunil Patil ◽  
Bhushan Langi ◽  
Minakshi Gurav ◽  
Digambar Patil

The mixed ligand lanthanum complexes have been synthesized using polydentate ligands. The (2Z)-2-(N-hydroxyimino)-1,2-diphenylethan-1-ol (cupron) was used as a primary ligand and L-isolucine, L-threonine, L-lysine and L-glycine were used as secondary ligands for the synthesis. Conductometry, elemental analysis, magnetic susceptibility measurements, complexometric estimation, UV-Visible spectroscopy, FTIR spectroscopy, thermal analysis and XRD methods were used for structural interpretation of all synthesized complexes. All complexes were solid and white and slight yellow in colour. They are non-electrolytic and diamagnetic in nature, as confirmed by conductometric and magnetic susceptibility methods respectively. All the complexes were synthesized by combination of lanthanum metal ion, primary ligand and secondary ligands in 1:2:1 ratio which was confirmed by elemental analysis. During reaction between lanthanum ion, primary ligand and secondary ligands there was transition of electrons which was confirmed by UV-Visible spectroscopy. Identification of functional group in the complexes was carried out and confirmed by FTIR spectroscopy. The decomposition temperature and thermal behaviour of the complexes have been concluded by thermal and XRD techniques. Tube dilution and agar cup methods have been employed to study antibacterial activities of all synthesized lanthanum complexes. The inhibition potential was seen to some extent.  


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