Highly Emissive Hexanuclear Rhenium(III) Clusters Containing the Cubic Cores [Re₆S₈]²⁺and [Re₆Se₈]²⁺

Abstract

Clusters based on the cubic, hexanuclear rhenium(III) core [Re6(μ3-Q)8]2+ (Q = S, Se) emit red phosphorescence with microsecond-scale lifetimes. Emission quantum yields of 16 clusters range from 1% to 23%; those having O-bound terminal ligands feature the highest yields and the longest liftimes. Certain clusters are photolabile, with medium-sensitive emissive properties. When photodecomplexation is suppressed, all clusters herein obey the energy gap law, indicating excitation confined to the [Re6Q8]2+ core.

Geometrically Specific Imino Complexes of the [Re6(μ3‐Se)8]2+ Core‐Containing Clusters

“…Indeed, their superior synthetic utilities have been demonstrated through the preparation of a great variety of molecular and supramolecular architectures. [5,[9][10][11] The use of the clusters in such developments, however, has been largely structural rather than functional, [12][13][14] and fundamentally new chemistry supported by the cluster core is conspicuously lacking.…”

Photoinduced Electron Transfer Reactions of Hexarhenium(III) Cluster: Oxidative Quenching of [Re6S8Cl6]4− Emission by Electron Acceptors

“…We reported previously, on the other hand, that hexarhenium(III) clusters, [Re 6 (l 3 -S) 8 X 6 ] 4-(X = Cl -, Br -, I -, and so forth), showed relatively intense room temperature emission in the visible * near infrared region (600-1,000 nm) with the emission lifetime (s) and quantum yield (U) in acetonitrile being s = 4-11 ls and U = 0.015-0.056, respectively [8] [15], N-heteroaromatics [16][17][18][19][20][21], phosphine derivatives [17,18,22,23], HCOO [24], CH3COO [25], and N 3 [26] [8,29]. Acetonitrile (Wako Pure Chemicals Co. Ltd.) as a medium throughout the study was purified by distillation over CaH 2 .…”

Cellular uptake and cytotoxicity of octahedral rhenium cluster complexes

“…Another interesting aspect of octahedral rhenium cluster complexes is their potential for photodynamic therapy (PDT) which is based on the excitation properties of a photosensitizer by visible or near-infrared light of a specific wavelength [7,8]. Recent studies showed that many octahedral rhenium cluster complexes both in solution [9][10][11][12][13][14][15][16][17][18][19][20][21] and in solid state [16,18,22] display photoluminescence just in the spectra region where PDT is effective. Thus, similar complexes can be considered as a novel class of potential photosensitizers for PDT.…”