Preparation and Luminescence of Cluster Compounds [W 6 Br 8 L 6 ] 2– with L = CF 3 COO and C 7 H 7 SO 3

Optically active cluster compounds [W 6 Br 8 L 6 ] 2– are prepared from Cs 2 [W 6 Br 14 ], which is obtained via reduction of WBr 6 with elemental antimony in the presence of CsBr. Cesium ions and six apical bromide ligands of Cs 2 [W 6 Br 14 ] are successively replaced for n ‐tetrabutyl ammonium (TBA) + and ligands (L). Light yellow single‐crystals of (TBA) 2 [W 6 Br 8 L 6 ] with L = CF 3 COO and C 7 H 7 SO 3 were isolated from dichloromethane solution and structurally characterized by means of X‐ray single‐crystal diffraction. Photoluminescence studies reveal a wide excitation range within 250 to 500 nm for both compounds and a broad emission centered at λ em,max = 735 nm (L = CF 3 COO) and 730 nm (L = C 7 H 7 SO 3 ). Oxygen dependencies of emission intensities are reported.