Oxidation and degradation of native wheat starch by acidic bromate in water at room temperature.

Native wheat starch was oxidized by benign acidic bromate in water at room temperature. HPLC-ELSD study indicated that starch degraded in the course of oxidation but it still had a polymeric structure characterized by (1)H, (13)C, HSQC and HMBC NMR measurements. Products were generally water-soluble fragments but the use of a short reaction time and dilute reaction mixture yielded water-insoluble products.

Fast and efficient benign oxidation of native wheat starch by acidic bromate under microwave activation.

A simple oxidation of starch in water by bromate was substantially improved by microwave activation. In the oxidation of native wheat starch its advantages were the highly reduced need of oxidant from 1.05 to 0.

Solid-contact ion-selective electrodes for aromatic cations based on pi-coordinating soft carriers.

Ion-selective electrodes (ISEs) based on pi-coordinating carriers were prepared and investigated as potentiometric sensors for aromatic cations, using N-methylpyridinium as a model aromatic cation. Derivatives of tetraphenylborate were studied as charged carriers in plasticized poly(vinyl chloride) membranes. Furthermore, neutral compounds containing pi-coordinating anthryl groups were studied as neutral carriers.

Two isomers of Pd2(S2NC7H4)4.

The dichloromethane solvates of the isomers tetrakis(mu-1,3-benzothiazole-2-thiolato)-kappa(4)N:S;kappa(4)S:N-dipalladium(II)(Pd-Pd), (I), and tetrakis(mu-1,3-benzothiazole-2-thiolato)-kappa(6)N:S;kappa(2)S:N-dipalladium(II)(Pd-Pd), (II), both [Pd2(C7H4NS2)4] x CH2Cl2, have been synthesized in the presence of (o-isopropylphenyl)diphenylphosphane and (o-methylphenyl)diphenylphosphane. Both isomers form a lantern-type structure, where isomer (I) displays a regular and symmetric coordination and isomer (II) an asymmetric and distorted structure. In (I), sitting on an centre of inversion, two 1,3-benzothiazole-2-thiolate units are bonded by a Pd-N bond to one Pd atom and by a Pd-S bond to the other Pd atom, and the other two benzothiazolethiolate units are bonded to the same Pd atoms by, respectively, a Pd-S and a Pd-N bond.

Synthesis, characterization, and complexation of tetraarylborates with aromatic cations and their use in chemical sensors.

Five aromatic borate anions, namely tetrakis(4-phenoxyphenyl)borate (1), tetrakis(biphenyl)borate (2), tetrakis(2-naphthyl)borate (3), tetrakis(4-phenylphenol)borate (4), and tetrakis(4-phenoxy)borate (5), have been prepared and tested as ion-recognition sites in chemical sensors for certain aromatic cations and metal ions. To gain further insight into the complexation of the cations, some complexes have been prepared and structurally characterized. The complexation behavior of 1 and 2 towards N-methylpyridinium (6), 1-ethyl-4-(methoxycarbonyl)pyridinium (7), tropylium (8), imidazolium (9), and 1-methylimidazolium (10) cations has been studied, and the stability constants of the complexes of 1 with cations 6 and 8 have been measured to compare them with the values for the previously studied complexes of tetraphenylborate.