Determination of thiourea and some of its organic derivatives with sodium vanadate, hexacyanoferrate(III), Cerium(IV) sulphate, manganese(III) and manganese(IV).
The determination of thiourea and some of its organic derivatives with sodium vanadate, hexacyanoferrate(III), cerium(IV) sulphate, manganese(III) and manganese(IV) is described. A mixture of iodate and iodide is used as catalyst. Ferroin, N-phenylanthranilic acid and p-ethoxychrysoidine can be used as indicators.
Kinetics and mechanism of oxidation of bis(2,2′,6′,2″-terpyridine) iron(II) by manganese(IV)
AbstractA study has been made on the oxidation of bis(2,2′,6′, 2″-terpyridine)-iron(II), Fe(tpy)22+ by manganese (IV) using stopped-flow spectrophotometry in H2SO4−H3PO4 mixtures. The reaction is first order in each the substrate and the oxidant. The rate of the reaction increases with hydrogen ion concentration. A plausible mechanism is proposed considering the protonated forms of manganese(IV) as reactive oxidizing species. The reaction obeys the rate law
$$k_{obs} \user2{ } = \user2{ }k^\prime [Mn(IV)]_t \user2{ }[H^ + ]^2 $$
AbstractПроведены кинетические исследования окисления бис(2,2′,6′,2″-терпиридин)железа(II), Fe(tpy)22+, марганцем(IV) в смесях H2SO4−H3PO4 с помщью спектрофотометрического метода остановленной струи. Реакция имеет первый порядок как по субстрату, так и по окислителю. Скорость реакции увеличивается с повышением концентрации иона водорода. Предложен механизм, полагающий, что протонированные формы марганца(IV) играют роль окисляющих частиц. Константа скорости реакции подчиняется следующему выражению:
$$k_{Ha6\pi } \user2{. } = \user2{ }k^\prime [Mn(IV)]_t \user2{ }[H^ + ]^2 $$

Self-assembly of pyridinium-tailored anthracene amphiphiles into supramolecular hydrogels.
The mixing of a polyacid cross-linker with a pyridinium-functionalized anthracene amphiphile afforded a supramolecular hydrogel through a self-assembly process that was primarily driven by π-stacking and electrostatic interactions.