Schiff bases of the type salicylidene 2-aminobenzothiazole and o-nitrobenzylidene 2-aminobenzothiazole were prepared by condensation of 2-aminobenzothiazole with salicylaldehyde and o-nitrobenzaldehyde. The bases react with cobalt(II), nickel(II) and copper(II) chlorides to give 1:1 and 1:2 complexes. Electronic spectra, magnetic susceptibility measurements and infrared data are used to infer the structures. The thermal decomposition of the complexes and evaluation of the thermodynamic parameters are also reported.

Studies on Some Schiff Base Complexes of CoII, NiII and CuII Derived from Salicylaldehyde and O-Nitrobenzaldehyde

http://www.damanhour.edu.eg/pdf/researches/1-s2.0-S0022286012000713-main.pdf

Synthesis and spectroscopic characterization of gallic acid and some of its azo complexes

Spectral and thermal studies of thiobarbituric acid complexes

Herein, we report the synthesis of a library of new s-triazine polyamides containing glycine and thioglycolic acid. The reaction of s-triazine dicarboxylic acid derivatives with ethylenediamine, benzidine, piperazine, or p-phenylenediamine, afforded the target designed s-triazine polyamides. The thermal properties of the polymers were evaluated by different techniques, and the thermodynamic parameters of the decomposition processes were evaluated. The feasibility of the synthesized polymers as drug nanodelivery systems was investigated. The nanoparticles were loaded with celecoxib (CXB), an anti-inflammatory drug with a highly promising anti-cancer effect, resulting in high entrapment efficiency levels (62.3–99.8%) with good drug loading in the range 1.58–4.19%. After 48 h, 46.90, 64.20, 57.81, 53.95, and 49.43% of CXB was released from polymeric NPs 26, 43, 44, 45, and 46, respectively, demonstrating a sustained drug release profile. Notably, free CXB, and CXB-loaded polymeric NPs CXB-43, CXB-45, and CXB-46 demonstrated considerable reduction in cell viability in a dose-dependent manner.

Design and synthesis of new s-triazine polymers and their application as nanoparticulate drug delivery systems

The thermodynamic and thermal properties of [Cu(L)2·Cl2], [Ni(L)2]·Cl2, [Co(L)2·Cl2]; L=1,2-bis(o-aminophenoxy)ethane (BAFE), complexes have been investigated. The thermal decomposition of the complexes took place in two distinct steps in endothermic reaction up to 700°C. The activation energy E, the entropy change S #, enthalpy H change and Gibbs free energy change G # were calculated from the results of thermogravimetry analysis (TG) and heat capacity from the results of differential scanning calorimetry (DSC). It was found that the thermal stabilities and activation energies of the complexes follow the order Ni(II)>Cu(II)>Co(II) and E Co<E Ni<E Cu, respectively.

Thermal analysis study of some transition metal complexes by TG and DSC methods

The thermal decomposition of the complexes: [Fe(C17H24O4)1.5·2H2O]n and [UO2(C17H24O4·2H2O]n, and evaluation of kinetic parameters (E, Z andΔS) by making use of Piloyan-Novikova, Coats-Redfern and Horowitz-Metzger equations are reported. The complexes are found to decompose in three well defined steps involving random nucleation mechanism. The intermediates formed during decomposition usually undergo further decomposition without remaining stable over a considerable range of temperature.

Kinetics and thermal decomposition of Fe(III) and UO2(II) complexes with embelin (2,5-dihydroxy-3-undecyl-P-benzoquinone)

The analysis of dehydration of the complexes, [La(C8H8NO3)3.2H2O] and [Yb(C8H8NO3)3.3H2O] for the evaluation of kinetic parameters (Z, E &δS*) and mechanism of dehydration by non-isothermal methods are reported. The complexes decompose in three well defined steps involving random nucleation mechanism. First two steps involving the dehydration and the third step the loss of the ligand moiety. The intermediates formed during decomposition were found to be unstable for carrying out any significant studies.

O. Singh

Papers

Kinetics and thermal decomposition of Fe(III) and UO2(II) complexes with embelin (2,5-dihydroxy-3-undecyl-P-benzoquinone)

Kinetics of thermal dehydration of La(III) and Yb(III) complexes with ortho-vanillin oxime