Hydrolysis of phosphodiester catalyzed by analogous dinuclear Cu(II) complex in CTAB micellar solution

Progress of Mimetic Enzymes and Their Applications in Chemical Sensors

The need to develop innovative and reformative approaches to synthesize chemical sensors has increased in recent years because of demands for selectivity, stability, and reproducibility. Mimetic enzymes provide an efficient and convenient method for chemical sensors. This review summarizes the application of mimetic enzymes in chemical sensors. Mimetic enzymes can be classified into five categories: hydrolases, oxidoreductases, transferases, isomerases, and induced enzymes. Potential and recent applications of mimetic enzymes in chemical sensors are reviewed in detail, and the outlook of profound development has been illustrated.

Synthesis and Studies of Hydrolysis of p-nitrophenyl picolinate catalysed by Schiff base zinc (II) complexes with aza-crown ether or morpholino-pendants

Four Schiff base zinc (II) complexes with either benzo-10-aza-crown ether pendants or morpholino-pendants have been synthesised and employed as models for hydrolase enzymes by studying the kinetics of their hydrolysis reactions with p-nitrophenyl picolinate (PNPP). A kinetic model of PNPP cleavage catalysed by these complexes is proposed. The effects of complex structures and reaction temperature on the rate of catalytic PNPP hydrolysis have been also examined. The rate increases with pH of the buffer solution; all four complexes exhibited high activity in the catalytic PNPP hydrolysis. Compared with their crown-free analogues, the crowned Schiff base complexes exhibit higher catalytic activity. The catalytic activity of a phenyl-bridged Schiff base complex is larger than that of an ethyl-bridged Schiff base complex under the same substitute groups and metal ion.

Aqueous solutions of transition metal containing micelles

Incorporation of d- or f-block metals into ligand systems that renders a metal complex surface-active or drives its partitioning into surfactant phases enables the localisation of chemical functionality at interfaces. This article discusses a number of fundamental aspects of these interesting materials and examines potential applications.

Kinetics of Hydrolysis of an Activated Phosphate Ester in Brij35 Micelle Containing a Macrocyclic Complex of Cu(II) OR Ni(II)

A macrocyclic ligand and its corresponding Cu(II) and Ni(II) complexes were synthesized and characterized. The kinetics of hydrolysis of bis( p-nitrophenyl) phosphate (BNPP, an activated phosphate diester) in Brij35 micelle containing each macrocyclic complex was investigated. The metallomicelles made up of the macrocyclic metal complex and micelle, as a mimic hydrolytic metalloenzyme, display higher catalytic activity although they do not attain the catalytic efficiency of enzymes. The analysis of specific absorption spectra show that the course of the catalytic BNPP reaction is different from that of the spontaneous hydrolysis of BNPP, and is an intramolecular nucleophilic substitution reaction. Based on the analytical results of the specific absorption spectra, an intramolecular nucleophilic substitution mechanism for the catalytic hydrolysis of BNPP is proposed, a correlative kinetic mathematical model is established, and the corresponding thermodynamic and kinetic constants are calculated. The validity of the mechanism and the proposed mathematical model is confirmed by the results of this study.