TUNING THE PHOTOPHYSICAL PROPERTIES OF ANTI-B18H22 [1]

The tuning of the photophysical properties of the highly fluorescent boron hydride cluster anti-B18H22 (1), by straight-forward chemical substitution to produce 4,4'-(HS)(2)-anti-B18H20 (2), facilitates intersystem crossing from excited singlet states to a triplet manifold.[1] This subsequently enhances O-2((1)Delta(g)) singlet oxygen production from a quantum yield of Phi(Delta) similar to 0.008 in 1 to 0.59 in 2. This contribution describes the synthesis and full structural characterization of the new compound 4,4'-(HS) 2-anti-B18H20 (2) and uses UV-vis spectroscopy coupled with DFT and ab initio computational studies to delineate and explain its photophysical properties. Additionally, we will report on new fluorescent derivatives of anti-B18H22 and their immobilisation on solid nanostructured substrates.