Expanding Luminescence Horizons in Macropolyhedral Heteroboranes.

Luminescence is observed in three novel macropolyhedral nineteen- and eighteen-vertex chalcogenaboranes: Se 2 B 17 H 17 (1), SeB 17 H 19 (3) and SeB 18 H 20 (4). This led us to the recognition that previously published macropolyhedral heteroborane species might also exhibit luminescence. Thus, the known nineteen- and eighteen-vertex dithiaboranes S 2 B 17 H 17 (2), n-S 2 B 16 H 16 (5) and i-S 2 B 16 H 16 (6) were synthesised and also found to exhibit a range of luminescent properties. These macropolyhedral species are very different from the previously unique fluorescent binary borane B 18 H 22 in terms of their structural architectures, by the presence of borane cluster hetero atoms, and, as in the cases of 5 and 6, that their synthetic origins are not derived simply through the modification of B 18 H 22 itself. They consequently greatly expand the possibilities of finding new luminescent inorganic borane species.