title: Temperature dependent emission of hexarhenium(III) clusters [Re6(mu3-S)8X6]4- (X = Cl-, Br-, and I-): analysis by four excited triplet-state sublevels.
abstract: Temperature (T) dependences of the emission spectra and lifetimes of hexarhenium(III) clusters, [Re6(mu3-S)8X6]4- (X = Cl-, Br-, and I-), in the crystalline phase were studied in detail. An increase in T from 30 to 70 K resulted in a red-shift of the emission spectrum of the cluster, while an increase in T above 70 K gave rise to a gradual blue-shift of the spectrum. On the other hand, the emission lifetime of the cluster decreased sharply from 30-40 to 13-20 micros on going from 30 to 60 K, while that decreased gradually above 60 K: 5-6 micros at 290 K. Such emission behaviors of [Re6(mu3-S)8X6]4- were observed irrespective of X. The results were then analyzed by assuming the contributions of the emissions from the lowest-energy excited triplet-state sublevels. The present study demonstrated that the characteristic T dependent emission spectra and lifetimes of [Re6(mu3-S)8X6]4- were explained reasonably by a single context of the contributions of the emissions from four excited triplet-state sublevels.
authors.affiliation: Division of Chemistry, Graduate School of Science, Hokkaido University, 060-0810 Sapporo, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Kitamura
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ueda
authors.forename: Shoji
authors.initials: S
authors.lastname: Ishizaka
authors.forename: Konatsu
authors.initials: K
authors.lastname: Yamada
authors.forename: Masanori
authors.initials: M
authors.lastname: Aniya
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Sasaki