Acylgermanes have been subject of great interest recently because of their low toxicity and the applicability as sources for germanium-centered radicals for visible-light induced free radical polymerization processes. We report on a novel and versatile method for the synthesis of tetraacylgermanes allowing the preparation of various tetra-substituted acylgermanes 1a–m. The formation of these derivatives was confirmed by NMR spectroscopy, mass spectrometry, and X-ray crystallography. UV–vis absorption spectra of the prepared compounds reveal absorption in the visible region. This transition was assigned by TD-DFT calculations. It enabled a general screening of the influence of different substitution patterns on the absorption properties. The radical formation upon irradiation was confirmed by TR-EPR spectroscopy.

中文翻译：

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四酰基germanes的合成，光谱行为和光诱导的反应性。

酰基锗烷由于其低毒性和作为可见光诱导的自由基聚合过程中锗中心自由基的来源的适用性而引起了人们的极大关注。我们报告了一种新颖且通用的四酰基锗烷的合成方法，允许制备各种四取代的酰基锗烷1a – m。这些衍生物的形成通过NMR光谱，质谱和X射线晶体学确认。所制备化合物的紫外可见吸收光谱显示其在可见光区域的吸收。此转换是通过TD-DFT计算分配的。它可以全面筛选不同取代模式对吸收性能的影响。通过TR-EPR光谱确认了辐射时的自由基形成。