Formation of heterocyclic C-60 derivative by gas-phase ion/molecule reaction

Ion/molecule reactions of C-60 with vinyl acetate under chemical ionization conditions have been studied here. Compared with C2H3O+ from acetone, C2H3O+ from vinyl acetate undergoes the reactions more easily, a new heterocycle between C-60 and the studied ion is formed The generation of two sigma-bonds and little angle tensile force of pentatomic ring make it more stable.

Iron(II)-8-quinolinol/MCM-41-catalyzed phenol hydroxylation and reaction mechanism

Iron(II)-8-quinolino/MCM-41 is prepared. Its catalysis is studied in phenol hydroxylation using H2O2 (30%) as oxidant. The experiment shows that Iron(II)-8-quinolinol/MCM-41 has good catalytic activity and desired stability. Based on cyclic voltammetry, ESR, and UV-visible spectra studies of iron(II)-8-quinolinol complex in liquid phase, a radical substitution mechanism is proposed and used to demonstrate the experimental facts clearly. (C) 1997 Academic Press.

Direct electron transfer reaction of horse heart hemoglobin at the indium oxide electrode

A direct, quasi-reversible electrochemical reaction of horse heart hemoglobin without further purification was obtained for the first time at the indium oxide electrode when oxygen was removed from the solution and hemoglobin molecules. It was found that removing oxygen from the solution and hemoglobin molecules is an important factor for obtaining the quasi-reversible electrochemical reaction of hemoglobin.

Phenol hydroxylation by iron(II) phenanthroline: The reaction mechanism

Phenol hydroxylation catalyzed by iron(II)-1,10-phenanthroline is investigated through kinetics, ESR, W-Vis as well as cyclic voltammogram studies. The optimum reaction conditions are obtained for diphenols production. Radical substitution mechanism is first proposed to explain the effects of pH, reaction medium and other factors on the phenol hydroxylation with H2O2 as oxidant, and found that the coexisting of iron(II)-1,10-phenanthroline and iron(III)-1,10-phenanthroline is the key for phenol hydroxylation to occur with H2O2 as oxygen donor.

In situ electrochemical scanning tunneling microscopy investigation of renewing graphite surface accompanied by electrochemical reaction

In situ electrochemical scanning tunneling microscopy (ECSTM) has been employed to follow the renewal process of a graphite electrode accompanied by flavin adenine dinucleotide (FAD) electrochemical reaction which involves adsorption of the reduced form (FADH(2)) and desorption of the oxidized form (FAD). The renewal process initiates from steps or kinks on the electrode surface, which provide high active sites for adsorption. This renewal depends on the working electrode potential, especially in the range near the FAD redox potential. Our experiment suggests that delamination of the graphite surface is caused by interaction between the substrate and adsorbed molecules. A simple model is proposed to explain this phenomenon.

A study of the radical reaction of C-60 with n-Bu(3)SnH

The reaction of buckministerfullerene (C-60) with tri-n-blltyltin hydride(n-Bu(3)SnH) in toluene solution has been investigated. According to mass spectrometry analysis, the products of above reaction are C-60(BuH)(n)(n = 1 similar to 3) and Bu(x)Sn(y)H(x) (x = 3 similar to 8, y = 1 similar to 4,approximate to = 0 similar to 3). The reaction maybe provide a new method for the synthesis of alkylated fullerene derivatives. Where C-60 also takes a role of a catalysis of organtic-tin polymerization. The radical reaction mechanism has been discussed.

THEORETICAL-STUDIES ON THE CYCLIZATION PROCESS OF A NEW ORGANOSULFUR REACTION

The cyclization process of a new organosulfur reaction was studied by the MNDO (UHF) method. The first reaction path was assumed to be via the organosulfur radical intermediate, the second via the ionic (cationic and anionic) intermediates. The dehydroxylation process was assumed to occur with the synergistic cyclization. The results obtained indicate that the potential energy barrier of the first reaction path was about 102 kcal mol(-1), and although the formation of the ionic intermediate is comparatively difficult, the potential energy barrier of the second path is comparable to the first. The sequential reaction path via the radical intermediate, i.e. first cyclization, then dehydroxylation, was investigated for comparison. The cyclization reaction was found to be the thermodynamically favored process, while the ensuing dehydroxylation process was found to have a potential energy barrier of about 62 kcal mol(-1).

PROMOTER EFFECT OF HALOGEN ANIONS ON THE DIRECT ELECTROCHEMICAL REACTION OF CYTOCHROME-C AT GOLD ELECTRODES

The promoter effect of halogen anions for heterogeneous electron transfer between cytochrome c and a gold electrode was studied. It was found that the order of the promoter ability of halogen anions is I- > Br- > Cl- > F-. In addition, factors which can affect the promoter effect were discussed.

STUDY ON THE KINETIC PROCESS OF THE COMPLEX-REACTION BETWEEN BILIRUBIN AND CYCLODEXTRINS

The complex behavior of bilirubin (BR) with beta-CD (cyclodextrin) and gamma-CD in aqueous and dimethylformamide (DMF) solution was investigated by absorption spectroscopy and cyclic voltammetry, respectively. The data shows that the complexation mechanis

REDOX REACTION OF PEROXIDASE AT POLY(O-PHENYLENEDIAMINE) MODIFIED ELECTRODE

The redox conversion of heme-containing protein horseradish peroxidase (HRP), which has a molar mass of 40,000, was studied. The conversion was obtained at an electrochemical polymerized o-phenylenediamine (PPD) film-modified platinum electrode. Optical c

ELECTROCHEMICAL REACTION OF CYTOCHROME-C AT GOLD ELECTRODES MODIFIED WITH THIOPHENE CONTAINING ONE FUNCTIONAL-GROUP

The electrochemical reactions of cytochrome c were studied at a thiophene-modified gold electrode. It was demonstrated that thiophene is an effective promoter, although there is only one functional group in the molecule. Based on this result, the mechanis

THE ISOLATION, CHARACTERIZATION AND OXIDATION REACTION OF ACTIVE INTERMEDIATES OF CYTOCHROME-P-450 MODEL SYSTEM OXOCHROMIUM(V) TETRAPHENYLPORPHYRIN COMPLEXES

Oxochromium (V) tetraphenylporphyrin complexes, O = Cr (V) TPP (Cl) PhI. O = Cr-(V) TPP (N3) PhI and O = Cr (V)TPP (p-CH3OC6H4O)1/2PhI were isolated from the reaction of Cr (III) TPP (Cl). Cr (III) TPP (N3) Py or Cr (III) TPP (p-CH3OC6H4O) THF with iodosy

THE APPLICATION OF ULTRAMICROELECTRODE IN HOMOGENEOUS CATALYTIC REACTION .5. ELECTROCHEMICAL-BEHAVIOR OF MACRO-MICRO-MACRO TRIPLE AND MICRO-MICRO TWIN ELECTRODES AND THE QUASI-FIRST-ORDER HOMOGENEOUS CATALYTIC REACTION (EC') AT GENERATION/COLLECTION ELECT

A new type of macro-micro-macro triple electrode has been fabricated, the steady-state currents of solution redox species have been observed at an ultramicroband electrode by linear potential scan voltammetry, and generation/collection experiments have al