Synthesis, Crystal Structure, and Luminescence of Metal Iodide Cluster Compounds (nBu4N)2[M6I8(NCO)6] with M = Mo, W

Molybdenum and tungsten iodide clusters with the [M 6 I 8 ] cluster core show versatile photophysical properties that strongly depend on the nature of six apical ligands ( L ) in [M 6 I 8 L 6 ] 2– . In course of our syntheses we report a new efficient preparation of Cs 2 [Mo 6 I 14 ] as precursor. Target compounds ( n Bu 4 N) 2 [ M 6 I 8 (NCO) 6 ] with M = Mo, W with cyanate ligands were synthesized and structurally characterized to study their photophysical properties. ( n Bu 4 N) 2 [ M 6 I 8 (NCO) 6 ] compounds appear as deep red (Mo) and light yellow (W) crystal powders showing strong phosphorescence. Compared to other cluster compounds of this type there is no significant concentration quenching obtained by the presence of molecular oxygen.