Manganese(III) Schiff-base complexes involving heterocyclic β-diketone and diethylene triamine

Abstract

Synthesis, spectral, thermal and coordination aspects of pentadentate Schiff-base complexes of the type [Mn(L)(X)] Á H 2 O [where H 2 L ¼ N,N 0 -diethylamine bis(1-phenyl-3-methyl-4-acetylimino-2-pyrazoline-5-ol) and X¼NCS, NO 3 , ClO 4 , CN or N 3 ] are reported. The Schiffbase ligand (H 2 L) and metal complexes have been characterized by elemental analysis, FT-IR, 1 H-NMR, magnetic measurements, molar conductivity measurements, electronic spectra, cyclic voltammetric and thermal studies. Magnetic moment values are close to 4.9 B.M. indicating high spin complexes lacking exchange interaction. Infrared spectral data suggest coordination of the secondary amino group making the ligand pentadentate. All complexes are electrochemically inactive, indicating high stability. Thermal decomposition of the Schiff-base complexes indicates loss of water of hydration and decomposition of the ligand. Kinetic parameters such as order of reaction (n) and the energy of activation (E a ) are reported using the Horowitz-Metzger method, indicating first order kinetics and giving the activation entropy (ÁS*), the activation enthalpy (ÁH*) and the free energy of activation (ÁG*).

Novel drug‐based Fe(III) heterochelates: synthetic, spectroscopic, thermal and in‐vitro antibacterial significance

“…Because of the presence of two active donor sites, they can form various types of metal complexes. In continuation to our earlier work on bis‐pyrazolone based compounds,28–30 herein we describe synthetic, spectroscopic, thermal and in‐vitro antibacterial studies of some novel drug‐based Fe(III) heterochelates. The general structure of the ligands (H 2 A n ) is shown in Scheme .…”

Synthesis, characterization, electrical and catalytic studies of some coordination compounds derived from unsymmetrical Schiff base ligand

“…1/T are found to be linear over studied temperature range and conductivity increases with increasing temperature. This suggests that the compounds behave as a semiconducting material [26,27] …”