Search Results

You are looking at 21 - 30 of 45 items for :

  • "2, 2′-Bipyridine" x
  • Refine by Access: All Content x
Clear All

Abstract  

New mixed ligand complexes of the following stoichiometric formulae: M(2-bpy)2(RCOO)2·nH2O, M(4-bpy)(RCOO)2·H2O and M(2,4’-bpy)2(RCOO)2·H2O (where M(II)=Zn, Cd; 2-bpy=2,2’-bipyridine, 4-bpy=4,4′-bipyridine, 2,4′-bpy=2,4′-bipyridine; R=C2H5; n=2 or 4) were prepared in pure solid-state. These complexes were characterized by chemical and elemental analysis, IR and conductivity studies. Thermal behaviour of compounds was studied by means of DTA, DTG, TG techniques under static conditions in air. The final products of pyrolysis of Cd(II) and Zn(II) compounds were metal oxides MO. A coupled TG/MS system was used to analyse of principal volatile products of thermal decomposition or fragmentation of Zn(4-bpy)(RCOO)2·H2O under dynamic air and argon atmosphere. The principal species correspond to: C+, CH+, CH3 +, C2H2 +, HCN+, C2H5 + or CHO+, CH2O+ or NO+, CO2 +, 13C16O2 + and 12C16O18O+ and others; additionally CO+ in argon atmosphere.

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors: Zhenrong Lu, Yuanchen Ding, Ying Xu, Shuhua Chen, and Yunpeng Yu

Abstract  

The thermal behaviors of [1,1,1-trifluro-3-(2-thenoyl)-acetonato]copper(II) Cu(TTA)2 and its adducts with pyridine Cu(TTA)2(Py)2, 2,2'-bipyridine Cu(TTA)2(Bpy), quinoline Cu(TTA)2(Ql)2, and dimethyl sulfoxide Cu(TTA)2(DMS) in a nitrogen atmosphere were studied under the non-isothermal conditions by simultaneous TG-DTG-DSC technique. The results showed that the evolution of the solvent molecules generally proceeded before the release of TTA in different ways according to their structures. The Cu(TTA)2(Bpy) exhibited a unique decomposition pattern due to its distinctive structure. The dependences of activation energy on extent of reaction for all the stage of each compound were determined by using an isoconversional method, Flynn-Wall-Ozawa equation, which show E values varied with reaction progress, indicating the complexity of these decomposition reactions. In addition, the values of activation energy E for TTA molecules evolution are generally higher than that for the solvent molecules release.

Restricted access

Abstract  

New mixed-ligands complexes with empirical formulae: M(2,4′-bpy)2L2�H2O (M(II)Zn, Cd), Zn(2-bpy)3L2�4H2O, Cd(2-bpy)2L2�3H2O, M(phen)L2�2H2O (where M(II)=Mn, Ni, Zn, Cd; 2,4′-bpy=2,4′-bipyridine, 2-bpy=2,2′-bipyridine, phen=1,10-phenanthroline, L=HCOO) were prepared in pure solid state. They were characterized by chemical, thermal and X-ray powder diffraction analysis, IR spectroscopy, molar conductance in MeOH, DMF and DMSO. Examinations of OCO absorption bands suggest versatile coordination behaviour of obtained complexes. The 2,4′-bpy acts as monodentate ligand; 2-bpy and phen as chelating ligands. Thermal studies were performed in static air atmosphere. When the temperature raised the dehydration processes started. The final decomposition products, namely MO (Ni, Zn, Cd) and Mn3O4, were identified by X-ray diffraction.

Restricted access

Abstract  

New mixed-ligand complexes with empirical formulae: Mn(2-bpy)1.5L22H2O, M(2-bpy)2L23H2O (M(II)=Co, Cu), Ni(2-bpy)3L24H2O and M(2,4’-bpy)2L22H2O (where 2-bpy=2,2’-bipyridine, 2,4’-bpy=2,4’-bipyridine; L=HCOO ) have been obtained in pure solid-state. The complexes were characterized by chemical and elemental analysis, IR and VIS spectroscopy, conductivity (in methanol and dimethylsulfoxide). The way of metal-ligand coordination discussed. The formate and 2,4’-bpy act as monodentate ligands and 2-bpy as chelate ligand. The new complexes with ligand isomerism were identified. During heating the complexes lose water molecules in one or two steps. Thermal decomposition after dehydration is multistage and yields corresponding metal oxides as final products. A coupled TG-MS system was used to analysis principal volatile thermal decomposition (or fragmentation) products of Ni(2,4’-bpy)2(HCOO)22H2O under dynamic air or argon atmosphere.

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors: Rabia Nazir, Muhammad Mazhar, Tehmina Wakeel, Muhammad J. Akhtar, Muhammad Siddique, Muhammad Nadeem, Nawazish A. Khan, and Muhammad R. Shah

ferrous chloride tetrahydrate was purchased from Merck and 2,2′-bipyridine from Sigma-Aldrich. Synthesis [Fe(bipy) 3 ]Cl 2 1.98 g (10 mmoles) of FeCl 2 ·4H 2 O in 100 mL dried THF was placed in a

Restricted access

halogenoacetates. Authors [ 23 , 24 ] synthesized and determined crystal structure of compounds type: [Ln(CCl 2 HCOO) 3 (2-bpy)] n (where Ln(III) = Nd, Pr; 2-bpy = 2,2′-bipyridine). Single crystals of [Gd 2 (CClF 2 COO) 6 (H 2 O) 2 (2-bpy) 2 ] 2 ·C 2 H 5 OH have

Open access

Chem Soc Jpn . 60 : 159 – 169 10.1246/bcsj.60.159 . 25. Rohde A , Urland W ( 2006 ) Catena-poly[[(2,2′-bipyridine-j2 N,N′)-neodymium(III)]-l-dichloroacetato-1j2

Restricted access

Re–Re and Re–C(O)O–Re species from Re(dmb)(CO)3S (dmb = 4,4′-dimethyl-2,2′-bipyridine, S = Solvent . J Am Chem Soc . 125 : 11976 – 11987 10.1021/ja035960a . 14. Ocakoglu , K , Emen

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors: Tingting Fang, Xi Li, Chenggang Wang, Zhijun Zhang, Tian Zhang, Junmin Zeng, Peng Liu, and Chaocan Zhang

properties when they are in the form of metallic complexes. The study of in vitro cytotoxicity of the complex (chloro)(2,2′-bipyridine)( N -propyl-norfloxacinato) copper(II) against two leukemia cell lines(HL-60 and K562) revealed an increased

Restricted access

2006 Catena-Poly[[(2,2′-bipyridine-j2N,N′)-neodymium(III)]-l-dichloroacetato-1j2O:O′:2jOdi-l-dichloroacetato-j4O:O] . Acta Crystallogr Sec E. 62 7 m1618 – m1619 10.1107/S1600536806022872 . 8

Open access