A ligand substituted tungsten iodide cluster: luminescence vs. singlet oxygen production

Abstract

Octahedral tungsten iodide clusters equipped with apical ligands (L) are synthesized to implement substantial photophysical properties. The [W₆I₈(CF₃COO)₆]²⁻ cluster reported herein is the first example of a family of ligand substituted [W₆I₈L₆]²⁻ clusters. Such compounds are expected to exhibit a rich photochemistry in which the apical ligands play a crucial role. The versatile solid state and solution phase photophysical properties of (TBA)₂[W₆I₈(CF₃COO)₆] described herein parallel characteristics obtained in some photophysically active organic compounds, including a broad absorption in the UV/VIS region. Upon irradiation of this compound, a broad red emission is observed in the VIS/NIR region resulting from excited triplet states, and singlet oxygen (a¹Δ_g) is generated in the presence of O₂.