Temperature Dependent Emission of Hexarhenium(III) Clusters [Re6(μ3-S)8X6]4- (X = Cl-, Br-, and I-):  Analysis by Four Excited Triplet-State Sublevels

• Published in: Inorganic chemistry Vol. 44; no. 18; pp. 6308 - 6313
• Main Authors: Kitamura, Noboru, Ueda, Yuichi, Ishizaka, Shoji, Yamada, Konatsu, Aniya, Masanori, Sasaki, Yoichi
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 05.09.2005
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic050855i

Temperature (T) dependences of the emission spectra and lifetimes of hexarhenium(III) clusters, [Re6(μ3-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 μs on going from 30 to 60 K, while that decreased gradually above 60 K:  5−6 μs at 290 K. Such emission behaviors of [Re6(μ3-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(μ3-S)8X6]4- were explained reasonably by a single context of the contributions of the emissions from four excited triplet-state sublevels.