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

Octahedral tungsten iodide clusters equipped with apical ligands (L) are synthesized to implement substantial photophysical properties. The [W6 I8 (CF3 COO)6 ]2- cluster reported herein is the first example of a family of ligand substituted [W6 I8 L6 ]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 [W6 I8 (CF3 COO)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 (a1 Δg ) is generated in the presence of O2 .