Thermal and photochemical studies of the system 18-molybdodiphosphate and iodide

Dimotikali, D; Papaconstantinou, E

dc.contributor.author	Dimotikali, D	en
dc.contributor.author	Papaconstantinou, E	en
dc.date.accessioned	2014-03-01T01:40:07Z
dc.date.available	2014-03-01T01:40:07Z
dc.date.issued	1990	en
dc.identifier.issn	10106030	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/23065
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-11544271052&partnerID=40&md5=16dcaf4dcb6032d366b472cb079a343e	en
dc.title	Thermal and photochemical studies of the system 18-molybdodiphosphate and iodide	en
heal.type	journalArticle	en
heal.publicationDate	1990	en
heal.abstract	18-Molybdodiphosphate [P2Mo18O62]6-, (Mo186-) and iodide react slowly until equilibrium is established {A figure is presented}. The reaction is first order with respect to molybdate and iodide, and seems to be first order with respect to H+ in the pH range of 0 to 2, where the molybdate is stable. Rate = k[I-][H+][Mo186-], k = 3.9 × 10-2 M-2 s-1 at 25 °C; Ea = 68.4 kJ mol-1 and ΔS = -48 J deg-1 mol-1. The equilibrium constant is 2 × 10-3. The thermal equilibrium shifts toward the reactants upon irradiation with light absorbed by the iodine and/or OM6+ charge transfer bands, whereas the mixed valence absorption M5+OM6+ (700 nm) is not photosensitive. The new equilibrium position, which reflects a balance between the photochemical and thermal reaction, depends on the wavelength and the light intensity. The equilibrium is re-established to the original position in the dark. The photolytic ""cycle"" was repeated many times without decomposition of the system. © 1990.	en
heal.journalName	Journal of Photochemistry and Photobiology, A: Chemistry	en
dc.identifier.volume	54	en
dc.identifier.issue	1	en
dc.identifier.spage	31	en
dc.identifier.epage	36	en