The X-ray crystal structures of three N-heterocyclic germylenes (NHGes) have been elucidated including the previously unknown 1,3-bis(2,6-dimethylphenyl)diazagermol-2-ylidene (1). In addition, the X-ray crystal structures of the previously synthesised 1,3-bis(2,4,6-trimethylphenyl)diazagermol-2-ylidene (2) and 1,3-bis(2,6-diisopropylphenyl)diazagermol-2-ylidene (3) are also reported. The discrete molecular structures of compounds 1 to 3 are comparable, with Ge-N bond lengths in the range 1.835-1.875 A, while the N-Ge-N bond angles range between 83.6 and 85.2°. Compound 2 was compared to the analogous N-heterocyclic carbene species, 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes). The major geometrical difference observed, as expected, was the bond angle around the divalent group 14 atom. The N-Ge-N bond angle was 83.6° for compound 2 versus the N-C-N bond angle of 101.4° for IMes. The Sn equivalent of (1), 1,3-bis(2,6-dimethylphenyl)diazastannol-2-ylidene (4), has also been synthesised and its crystal structure is reported here. In order to test their suitability as ligands, compounds 1 to 3 were reacted with a wide range of transition metal complexes. No NHGes containing metal complexes were observed. In all cases the NHGe either degraded or gave no reaction.

中文翻译：

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N-杂环锗烯：无处不在的 N-杂环卡宾的一些重类似物的结构表征

已经阐明了三种 N-杂环锗烯 (NHGes) 的 X 射线晶体结构，包括以前未知的 1,3-双 (2,6-二甲基苯基) diazagermol-2-ylidene (1)。此外，先前合成的 1,3-双 (2,4,6-三甲基苯基) diazagermol-2-ylidene (2) 和 1,3-bis(2,6-diisopropylphenyl) diazagermol-还报道了 2-亚基 (3)。化合物 1 至 3 的离散分子结构相当，Ge-N 键长范围为 1.835-1.875 A，而 N-Ge-N 键角范围为 83.6 至 85.2°。将化合物 2 与类似的 N-杂环卡宾物质 1,3-双(2,4,6-三甲基苯基)咪唑-2-亚基 (IMes) 进行比较。正如预期的那样，观察到的主要几何差异是围绕二价基团 14 原子的键角。N-Ge-N键角为83。化合物 2 为 6°，而 IMes 的 NCN 键角为 101.4°。(1), 1,3-双(2,6-二甲基苯基)diazastannol-2-ylidene (4) 的 Sn 等价物也已合成，其晶体结构在此报道。为了测试它们作为配体的适用性，化合物 1 到 3 与范围广泛的过渡金属配合物反应。没有观察到含有金属络合物的 NHGe。在所有情况下，NHGe 要么降解，要么不发生反应。