Chromium, named for its many-colored compounds, exists in the oxidation states of -2 to +6 inclusively. The compounds exhibit a wide range of geometries including square planar, tetrahedral, octahedral, and various distorted geometries. Chromium is found in nature principally as the chromite ore FeCr2O4 in which chromium is in the +3 state. The existence of a particular oxidation state is depen...

A convenient method of preparing ultrafine poly(methylstyrene) (PMS) latex particles with aldehyde groups on the surface is developed. PMS latexes in the size range 33–81 nm were prepared via microemulsion polymerization, using cetyltrimethylammonium bromide (CTAB) as surfactant. The surface of the PMS latexes was oxidized in the presence of tert-butyl hydroperoxide catalyzed by copper(II) chlo...

Polyaniline nanoparticles were prepared using oxidation polymerization in micro-emulsion system. Sodium dodecyl sulphate was used as a surfactant which dissolved in hydrochloric acid giving the micellar solution. Potassium persulphate was used as an oxidant. The produced particles were spherical in shape with an average diameter of 15 nm as detected from the transmittance electron microscope im...

The expression of Klebsiella pneumoniae hpaA and hpaH genes, which code for 4-hydroxyphenylacetic acid hydroxylase in Escherichia coli K-12 derivative strains, is associated with the production of a dark brown pigment in the cultures. This pigment has been identified as a polymer which shows several of the characteristics reported for microbial melanins and results from the oxidative activity o...

The kinetics of oxidation of allyl alcohol by quinaldinium chlorochromate is investigated in 40 % acetic acid – water (v/v) medium. The order with respect to oxidant and hydrogen ion concentration is found to be one and fractional with respect to substrate. The rate of the reaction is decreases with the decrease in the dielectric constant of the medium. The rate of the reaction has negligible e...

Soil-induced oxidation and subsequent polymerization of aromatic amines is an important pathway for reducing the mobility of amines in soils and their hazard potential in the environment. This study assesses the hypothesis that manganese(III/IV) oxides/hydroxides play a significant role in the oxidation of aromatic amines in whole soils. Aromatic amines including alpha-naphthylamine, p-methoxya...

Chitooligosaccharide with one 2,5-anhydro-D-mannofuranose unit at the reducing end (COSamf) was prepared by nitrous deamination of fully N-deacetylated chitosan. The oxidation of the amf-unit by chlorite sodium was achieved in high yield. The chemical structure of the targeted chitooligosaccharide-2,5-anhydro-D-mannonic acid with a degree of polymerization ~10 was fully characterized by NMR spe...

Polyindole nanowires were synthesized by oxidative polymerization of indole using ammonium persulphate as oxidant. The structure of polyindole nanowires was confirmed by XRD, FTIR spectroscopy. The FT-IR of polyindole nanowires shows a peak at1480 cm which corresponds to the C-N stretching of the polymer. The morphology was studied by FESEM, which shows that the synthesized polymer has wire-lik...

A novel monomer of S-2-mercaptoethyl 2-(thiophen-3-yl)ethanethioate (MTE) were synthesized via esterification reaction between 2-(thiophen-3-yl)acetic and ethane-1,2-dithiol in the presence of dicyclohexyl-carbodiimide (DCC) and N,N’-dimethylpyridin-4-amine (4-DMAP) as catalytic system. The structure of monomer was characterized via MS, 1H-NMR and 13C-NMR spectroscopies. The electrochemical pol...