It is expected that catenated compounds of germanium might function as luminescent or optical materials once a sufficient number of germanium atoms are connected together in the chain. We have prepared and characterized the penta- and hexagermanes Pri3Ge(GePh2)nGePri3 (n = 3 or 4), where the hexagermane is the longest structurally characterized linear oligogermane reported to date. Initial studies indicated that these molecules were luminescent in solution, and we have now investigated its photophysical properties of Pri3Ge(GePh2)4GePri3 in the solid state. The hexagermane exhibits temperature dependent absorbance and emission spectra, where vibrational fine structure is observed below 240 K. In addition, a blue emission in the visible region is observed upon excitation at 300 nm at 80 K. The synthesis of the two oligogermanes Pri3Ge(GePh2)nGePri3 (n = 3 or 4) and the nature of its absorbance and emission properties will be discussed in conjunction with DFT investigations. The structure/property relationships of other oligogermanes, including the branched systems (Ph3Ge)3GeX (X = H, F, Cl, Br, I, Ph, or GePh3), will also be discussed.














Scott Weinert (Oklahoma State University)