Supermolecular complexes of d-metal (Mo, W) anions with polyvinyl alcohol in aqueous solution / Ostroushko AA,Vilkova NV,Popov KA // RUSSIAN JOURNAL OF INORGANIC CHEMISTRY. - 2000. - V. 45, l. 4. - P. 638-643.

ISSN/EISSN:

0036-0236 / нет данных

Type:

Article

Abstract:

The formation of supermolecular complexes between d-metal (Mo, W) polyanions and polyvinyl alcohol (PVA) in aqueous solution was studied by turbidimetry and viscosimetry. There are five or more functional groups of the polymer per metal atom. The number of associated groups per metal atom, n, falls stepwise with increasing the salt concentration, reflecting the decrease in the polyanion charge. Ammonium heptamolybdate and paratungstate, (NH4)(6)Mo7O24. 4H(2)O and (NH4)(10)W12O41. nH(2)O, were used as the starting salts. For the molybdate-PVA complexes, the formation constant was estimated spectrophotometrically. Reversible partial photochemical reduction of Mo(VI) in PVA-salt supermolecular complexes was observed for the first time. The most likely mechanism of the reaction involves electron phototransfer from the polymeric chain to the d-metal ion. The threshold wavelength and quantum yield were determined for the reaction, as well as the effective oxidation number of molybdenum in its complexes. Rare-earth (La, Y) ions, broadening the absorption band in the electronic spectrum of Mo, sensitize the molybdate-PVA complexes. Furthermore, these ions link polymeric molecules into a three-dimensional network, promoting the formation of a stable polymer-salt gel.

Author keywords:

нет данных

DOI:

нет данных

Web of Science ID:

ISI:000088988300024

Соавторы в МНС:

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Другие поля

Поле	Значение
Month	APR
Publisher	INTERPERIODICA
Address	PO BOX 1831, BIRMINGHAM, AL 35201-1831 USA
Language	English
Research-Areas	Chemistry
Web-of-Science-Categories	Chemistry, Inorganic \& Nuclear
Number-of-Cited-References	17
Journal-ISO	Russ. J. Inorg. Chem.
Doc-Delivery-Number	348MJ