The hexagermane Pri3Ge(GePh2)4GePr i3 (1) can adopt four different conformations by rotations about its germanium –germanium single bonds that differ in energy across an energy range of 31.63 kJ/mol, with the trans-coplanar arrangement having the lowest energy. Conformational changes can occur among these four structures resulting in the observation of thermochromic absorbance spectra both in solution and in the solid state. Bathochromic shifts of 5 nm and 15 nm were observed in solution and in the solid state with increasing temperature. Compound 1 is also luminescent both in solution and in the solid state. The solution emission spectra are solvent dependent and the solid state emission maxima were shown to be temperature dependent. When 1 is excited at 300 nm in the solid state at 80 K its emission spectrum contains a broad emission peak in the visible region and this emission can be observed with the naked eye. The indirect band gap of 1 was determined to be 3.25 eV, which is consistent with investigations on other related oligogermane systems.

中文翻译：

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溶液中的吸收和发射研究以及 Pr i 3Ge(GePh 2) 4GePr i 3 的固态和带隙测定

六锗烷 Pri3Ge(GePh2)4GePr i3 (1) 可以通过围绕其锗-锗单键旋转采用四种不同的构象，这些构象在 31.63 kJ/mol 的能量范围内具有不同的能量，其中跨共面排列具有最低能量。这四种结构之间可能会发生构象变化，从而导致在溶液和固态下都观察到热致变色吸收光谱。随着温度的升高，在溶液和固态中观察到 5 nm 和 15 nm 的红移。化合物 1 在溶液和固态下也能发光。溶液发射光谱依赖于溶剂，固态发射最大值显示为依赖于温度。当 1 在 80 K 的固态下在 300 nm 处被激发时，其发射光谱在可见光区包含一个宽发射峰，这种发射可以用肉眼观察到。1 的间接带隙被确定为 3.25 eV，这与对其他相关低聚锗烷系统的研究一致。