Authors:San-Ping Chen, Na Li, Qing Wei, and Sheng-Li Gao
A novel complex [Ni(H2O)4(TO)2](NO3)2·2H2O (TO = 1,2,4-triazole-5-one) was synthesized and structurally characterized by X-ray crystal diffraction analysis. The decomposition
reaction kinetic of the complex was studied using TG-DTG. A multiple heating rate method was utilized to determine the apparent
activation energy (Ea) and pre-exponential constant (A) of the former two decomposition stages, and the values are 109.2 kJ mol−1, 1013.80 s−1; 108.0 kJ mol−1, 1023.23 s−1, respectively. The critical temperature of thermal explosion, the entropy of activation (ΔS≠), enthalpy of activation (ΔH≠) and the free energy of activation (ΔG≠) of the initial two decomposition stages of the complex were also calculated. The standard enthalpy of formation of the new
complex was determined as being −1464.55 ± 1.70 kJ mol−1 by a rotating-bomb calorimeter.
Authors:B. Carson, G. Kenessey, J. Allan, and G. Liptay
The chloro complexes of cobalt, nickel and copper with 3-phenylpyridine were prepared in ethanolic solution from which solid
compounds were isolated. The cobalt and copper complexes have stoichiometry M2LCl4 while the nickel complex has stoichiometry NiLCl2. The suggested structure for the cobalt and copper complexes is tetrahedral, while for the nickel complex it is octahedral.
Thermal analysis studies show that the cobalt and copper complexes form intermediate complexes before their metal oxides are
produced. The nickel complex also forms an intermediate complex and then nickel chloride before the nickel oxide is obtained.
Authors:O. Çakırer, E. Eker, Ü. Ergun, E. Gökçınar, L. Tatar Yıldırım, H. Dal, and O. Atakol
Two ONNO type naphtaldehyde derivative Schiff base compounds were reduced and two symmetric phenol-amine ligands containing
naphthalene groups were obtained; bis-N,N′[(2-hydroxy-1-naphtyl) methyl]-1,3-propanediamine (NAFLH) and bis-N,N′[(2-hydroxy-1-naphtyl) methyl]-2,2′-dimetyhyl-1,3-propanediamine (NAFLDMH). Homotrinuclear Ni(II) complexes of these ligands were prepared. The solid-state molecular structures of representative
nickel complex of NAFLDMH were determined using single crystal X-ray diffraction analysis. The terminal Ni(II) ions were found to be situated in between
the donor atoms of the organic ligand. The central Ni(II) ion was observed to be bonded via two different μ-bridges. The phenolic
oxygens and carboxylate ion were seen to form two different μ-bridges. TG analysis proved that the compounds have different
thermal characteristics than those cited in literature. The complexes showed extreme exothermic degradation reactions in inert
atmosphere. The complexes are ruptured with a two stepped exothermic reaction which appears huge heat over 300 °C. The heat
appeared in O2 atmosphere is observed to be higher than the heat appeared in inert atmosphere. Revealed heat is observed to be higher than
the conventional explosive materials.
Cobalt, nickel and zinc dicarboxylate complexes containing neutral hydrazine
as bridged bidentate ligand of the type MX(N2H4)n
where n=1 for X=OOCCH2COO
and n=2 for X=OOCCH2COO,
OOCCH2CH2COO and OOCC(CH2)CH2COO
have been prepared by aqueous reactions. These complexes have been characterized
by analytical, spectral and thermal studies. The electronic spectra coupled
with magnetic moments of cobalt and nickel complexes suggest these complexes
are of high-spin variety with octahedral geometry. Infrared spectra indicate
the bridging bidentate nature of hydrazine moieties present in both mono-hydrazine and bis-hydrazine
complexes and the dicarboxylate ions coordinate to the metal as bidentate
ligand through the monodentate coordination of each carboxylate ion. However,
in the mono-hydrazine metal malonates both
carboxylate ions act as bridged ligands.
Simultaneous TG-DTA curves
of all the complexes in air resulted in the formation of respective metal
oxide as final residue at low temperatures (300–400C). These complexes
decompose either in single step or decompose through respective metal carboxylate
intermediates. In most of the cases the decompositions are exothermic while
in some cases they are violently exothermic. The thermal degradation of these
complexes in nitrogen atmosphere also gives the respective metal oxide as
the final residue.
Authors:Gurdip Singh, A. K. Shrimal, Inder Pal Singh Kapoor, Chandra Prakash Singh, Dinesh Kumar, and Manan S. Mudi
observed for zinc, copper, and nickelcomplexes, respectively ( Table 2 ). Corresponding to this first step mass loss, DTG peaks are obtained. Although the thermolysis is done up to the temperature of 893 K, the residue left is more than the corresponding
–Metzger (HM) and MacCallum–Tanner (MT) [ 6 – 9 ].
The nickelcomplexes were synthesized as per the procedure reported in the literature [ 10 ]. Nickel content in the complexes was determined by gravimetry [ 11 ]. The
Authors:S. K. Mehta, Ravneet Kaur, and Sukhjinder Singh
The value of reaction order, n , is around 1 for decomposition of all the complexes synthesized. Based on the TG traces, it can be elucidated that nickelcomplex is thermally the least stable out of all the complexes, which is in accordance with the
Authors:Rodica Olar, Mihaela Badea, Dana Marinescu, Larisa Calu, and Cristina Bucur
concerning antiviral activity [ 3 – 5 ].
The importance of the complexes with bicyclams derived from the fact that they are active against both HIV-1 and HIV-2 [ 6 ]. Among these, the zinc and nickelcomplexes with the some bicyclams are slightly more
et al. [ 2 ] have reported the formation of ultrafine metallic copper wires by the thermal decomposition of tris(ethylenediamine)copper(II) halides. Syntheses of nano NiO or Ni by the thermal decomposition of nickelcomplexes have also been reported
Authors:Irena Szczygieł, Zofia Jagoda, Julia Kłak, and Maria Korabik
( Fig. 5 ) consists of the d – d type bands from different ions of the two metals with their different symmetry and the CT transition bands. A broad band at 474 nm corresponds to d – d transitions of a nickel ion, which is typical of nickelcomplexes