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Five new chloranilato-bridged binuclear chromium (III) complexes have been synthesized and Identified as [Cr2(CA)L4]-(ClO4)4 [L denotes 5-methyl-1,10-phenanthroline (Me-phen); 2,9-dimethyl-1,10-phenanthroline (Me2-phen); 5-chloro-1,-10-phenanthroline (Cl-phen); diaminoethane (en) or 1,3-diaminopropane (pn)], where CA represents the dianion of chloranilic acid. Based on elemental analyses, molar conductivity and magnetic moment of room-temperature measurements, and IR and electronic spectral studies, it is proposed that these complexes have CA-bridged structures and consist of two chromium (III) ions, each in an octahedral environment. The complexes [Cr2(CA)(Me-phen)4](ClO4)4(1) and [Cr2(CA)(Me2-phen)4](CIO4)4(2) were further characterized by variable temperature (4.2–300 K) magnetic susceptibility measurements and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, Ĥ= -2 JS1·Ŝ2, giving the exchange parameter J= -7.8 cm−1 for (1) and J= -6.5 cm1 for (2). This result indicates that there is weak ant ferromagnetic spin-exchange interaction between the two chromium (III) ions within each molecule.

Homodinuclear and heterodinuclear Zn(II) and Cu(II) complexes derived from macrocyclic ligand (1) have been kinetically examined as catalysts for the hydrolysis of phosphomonoester p‐nitrophenyl phosphate (pNPP) in Brij35 micellar solutions. Kinetic data indicated that the aquo‐hydroxy form of the dinuclear complex was the active species and the metal‐coordinated hydroxide nucleophile attacked the substrate in the hydrolysis reaction in a fashion of intramolecule nucleophilic reaction. Two oxygens of pNPP associated with the two metal centers of the dinuclear complex, and in this case the metal ions exerted a double Lewis acid effect. Different structure requirements of metal ions and nucleophilicity of M‐OH species determined the activity sequence of the three dinuclear complexes. The rigid and compact geometry of these complexes hindered their catalytic effects in the hydrolysis of phosphodiester bis(p‐nitrophenyl) phosphate (BNPP).

Hydrolysis of p‐nitrophenyl picolinate (PNPP) mediated by the micellar catalytic systems of two gemini cationic surfactants with different hydrophobic tail groups (ethanediyl‐1,2‐bis(dodecyldimethylammonium bromide) (12‐2‐12, 2Br−), dimethylene‐1,2‐bis(cetyltrimethyl‐ammonium bromide) (16‐2‐16, 2Br−)) was investigated spectrophotometrically in the pH range of 7.0–9.0 and at 25°C. It is noteworthy that (1) two gemini surfactants showed catalytic effects on the hydrolysis of PNPP and gemini surfactant (16‐2‐16, 2Br−) enhanced the hydrolytic reaction notably more than gemini surfactant (12‐2‐12, 2Br−) micellar solutions under the same reaction conditions, which may be ascribed to the micelle effect and (2) the apparent rate constants (k obsd) of PNPP hydrolyses increased with increasing pH values of the reaction media.

The imidazole derivatives (N,N‐bis(2‐ethyl‐5‐methyl‐imidazole‐4‐ylmethyl) amino‐propane (biap)) and its complexes containing cobalt or copper ion were synthesized in this study. The oxidation reaction of phenol with oxidant H2O2 catalyzed by the metallomicelle made of the complexes of imidazole groups and micelle (CTAB, Brij35, LSS) as the mimetic peroxidase was studied. The results show that the reaction rate for the catalytic oxidation of phenol increases by a factor of approximately 1×105 in the metallomicelle over that in the simple micelles or the pure buffer solution at pH=6.9 and 25°C. The catalytic effects changed with H2O2, temperature, pH, and surfactant kind in the catalytic reactive process are discussed. A kinetic mathematic model of the phenol oxidation catalyzed by the metallomicelle is proposed.

The syntheses of two alkanol‐pyridyl ligands, 6‐(n‐dodecyloxymethyl) ‐2‐(hydro‐xymethyl)pyridine (1) and 6‐(methyloxymethyl)‐2‐(hydroxymethyl)pyridine(2), are reported. Metallomicellar systems made of complexes of these ligands with Cu(II), Zn(II), Ni(II), and Co(II) in the presence of surfactant CTAB are efficient catalyzers in the hydrolysis of bis(p‐nitrophenyl)phosphate (BNPP). The experimental results indicate that 2∶1 ligand:metal ion complexes in CTAB micellar solution are the active species for the catalytic hydrolysis of BNPP. The ternary complex kinetic model for metallomicellar catalysis was employed to treat the results to obtain the relative kinetic and thermodynamic parameters. The results predicted the reasonability of such kinetic models.

Three novel mono-Schiff base manganese(III) complexes (metal: ligand = 1 : 2) with benzoaza-15-crown-5 or morpholine pendant groups, were shown to promote the hydrolysis of p-nitrophenol picolinate (PNPP) under a series of experimental conditions. A mechanism for these catalysts is proposed in which the H2O molecule that hydrolyses the PNPP is deprotonated by the synergistic effect which results from central Mn(III) ion and oxygen atom located in the benzoaza-15-crown-5 or morpholine ring. The related kinetic model has been set up. The effects of structural differences of the listed complexes on the hydrolysis of PNPP have been discussed. The experimental results imply that the steric hindrance of side pendant groups is a primary factor for PNPP hydrolysis.

The hydrolysis of p‐nitrophenyl phosphate (NPP) catalyzed by metallomicelles formed from four asymmetry CuIINiII heterodinuclear oxamido‐bridged complexes, whose ligands contain different diamine groups, and nonionic surfactant Brij35 has been investigated quantitatively at the pH range of 6.0–10.5 and 25°C, respectively. The results indicated that the rates of catalytic hydrolysis of NPP by four complexes in Brij35 micellar solution were all largely enhanced under the experimental conditions. The order of effectiveness of the four complexes in Brij35 micellar solutions toward hydrolysis of NPP was found to be: complex I>complex II>complex III>complex IV. The different catalytic function of four complexes may be attributed to the different activation abilities of coordinated water molecules induced by different polarities of ligands, which has been discussed in detail. Meanwhile, kinetic studies show that the active species in the catalytic hydrolysis of NPP may be the aquo‐hydroxy form and that the mecha...

A crowned Schiff base ligand and its cobalt(II) and manganese(III) complexes were synthesized and characterized, and the metallomicelles made from the complexes and micelles (Brij35, LSS, CTAB) were investigated to catalyze the hydrolysis of bis(4‐nitrophenyl) phosphate (BNPP). A kinetic mathematical model for simulating enzyme catalyzing reaction was proposed and employed to analyze the mechanism of BNPP catalytic hydrolysis. Michanelis constant and the apparent active energy for the catalytic reaction were calculated. The kinetic studies showed that the metallomicelle made from the micelle and crowned Schiff base transitional metal complexes is an effective mimetic hydrolytic enzyme for BNPP catalytic hydrolysis.