Preparation, photoluminescence and excited state properties of the homoleptic cluster cation [(W6I8)(CH3CN)6]4+

Solvated tungsten iodide cluster compounds are presented with the homoleptic cluster cation [(W6I8)(CH3CN)(6)](4+) and the heteroleptic [(W6I8)I(CH3CN)(5)](3+), synthesized from W6I22 in acetonitrile. Crystal structures were solved and refined on deep red single-crystals of [(W6I8)(CH3CN)(6)](I-3)(BF4)(3)center dot H2O, [(W6I8)I(CH3CN)(5)](I-3)(2)(BF4), and on a yellow single-crystal of [W6I8(CH3CN)(6)](BF4)(4)center dot 2(CH3CN) on the basis of X-ray diffraction data. The structure of the homoleptic [(W6I8)(CH3CN)(6)](4+) cluster is based on the octahedral [W6I8](4+) tungsten iodide cluster core, coordinated by six apical acetonitrile ligands. The electron localisation function of [(W6I8)(CH3CN)(6)](4+) is calculated and solid-state photoluminescence and its temperature depedence are reported. Additionally, photoluminescence and transient absorption measurements in acetonitrile are shown. Results of the obtained data are compared to compounds containing [(M6I8)I-6](2-) and [(M6I8)L-6](2-) (M = Mo or W; L = ligand) clusters.

Automated summary

Solvated tungsten iodide cluster compounds, including [(W6I8)(CH3CN)(6)](4+) and [(W6I8)I(CH3CN)(5)](3+), were synthesized in acetonitrile and their crystal structures were determined by X-ray diffraction. The structure of [(W6I8)(CH3CN)(6)](4+) consists of an octahedral [W6I8](4+) core coordinated by six apical CH3CN ligands. The electron localisation function of [(W6I8)(CH3CN)(6)](4+) was calculated and its solid-state photoluminescence and temperature dependence were investigated. Photoluminescence and transient absorption measurements in acetonitrile were also performed, and the results were compared with compounds containing [(M6I8)I-6](2-) and [(M6I8)L-6](2-) (M = Mo or W; L = ligand) clusters.