Schiff base and its one di-µ-oxidovanadium(V) complex have been synthesized by the reaction of vanadyl sulphate pentahydrate and N'-[(Z)-phenyl(pyridin-2-yl)methylidene]pyridine-4-carbohydrazide (HL). The HL and its complex [(L)VO(µ-O)2VO(L)] have been characterized by micro-analysis, UV-visible and electrochemical techniques. The ligand and its complex have also been characterized by single crystal X-ray technique. The ligand crystallizes in triclinic crystal system with P1  space group while, complex crystallizes in monoclinic crystal system with P21/c space group. The electronic spectrum is as expected for vanadium(V) in an octahedral environment in each vanadium centers. The electronic structures of the ligand and the complex have been explained by density functional theory (DFT) calculations. In addition, in vitro insulin mimetic activity of the complex has also been evaluated.

The kinetic and mechanistic study of homogeneously Pd(II)-catalyzed oxidation of ampicillin by Cu(Bipy)2 2+ in alkaline medium have been conducted at 35 ± 0.1 ºC. Spectrophotometric titrations show that the stoichiometry of the reaction is 1:4 ([ampicillin]:[Cu(Bipy)2 2+] = 1:4). The first order kinetics is observed regarding [Cu(Bipy)2 2+] and [Pd(II)] however, less than unity order exhibited by [OH–]. On varying [ampicillin] and [bipyridyl], velocity of reaction remains unchanged. Reaction rate unaffected by changing ionic strength of the medium while with dielectric constant, it shows inverse relation. Various thermodynamic properties of reaction were calculated such as activation energy, activation entropy, etc. Oxophenyl acetic acid and 2-formyl-5,5-dimethylthiazolidine-4-carboxylic acid were identified as reaction product. With the help of kinetic observation, spectrophotometric data an appropriate reaction mechanism and rate law derived for aforesaid reaction.

In present study, the kinetics and mechanism of oxidation of pentoxifylline (PTX) by N-chlorosuccinimide (NCS) in acidic conditions at 40 ± 0.1 ºC is reported. The reaction depicts first-order kinetics in regard to [NCS], [PTX] and [HClO4]. The reaction rate goes on decreasing as the concentration of iridium(III) chloride is increased. This shows that iridium(III) chloride plays the role of an inhibitor in the reaction under investigation. Nil impact of [Hg(OAc)2], [NHS] and dielectric constant (D) of the medium on the rate of oxidation of pentoxifylline have been observed. This reaction has been investigated from 308-323 K and the monitored rate of reaction suggests a direct relationship between temperature and the rate of reaction. From the graph between log k and 1/T, value of activation energy (Ea) was numerated and more activation parameters like enthalpy of activation (ΔH#), entropy of activation (ΔS#) and free energy of activation (ΔG#) were calculated with the help of activation energy (Ea). On account of experimentally determined the kinetic orders and activation parameters, a most plausible reaction path has been suggested for the oxidation of pentoxifylline in presence of Ir(III) as an inhibitor.