The Squaric Acid Derivatives C<sub>8</sub>O<sub>4</sub>S<sub>2</sub> and C<sub>8</sub>O<sub>4</sub>Se<sub>2</sub> – Crystal Structures, Explosive Thermal Behavior and the Preparation of Carbon Suboxide Selenide OC<sub>3</sub>Se by Flash Vacuum Pyrolysis
作者:Johannes Beck、Petra Krieger-Beck、Klemens Kelm
DOI:10.1515/znb-2006-0202
日期:2006.2.1
the decomposition of C8O4S2 in a closed autoclave leaves a residue of the composition “C6S” which was examined by transmission electron microscopy techniques and shown to consist mainly of amorphous carbon. This thermal behaviour is limiting the utilization of C8O4S2 and C8O4Se2 as precursors for the syntheses of OC3S and the yet unknown OC3Se via FVP. The formation of OC3S could be proven by the reaction
摘要 2,7-二硒三环[6.2.0.03.6]deca-1,3-diene-4,5,9,10-tetraone,C8O4Se2,由1,2-二硒方酸和方酸二氯化物制备而成。确定了其晶体结构和已知硫类似物 C8O4S2 的结构(C8O4S2:正交、Pca21、a = 1413.64(2)、b = 599.850(9)、c = 968.8(1) pm;C8O4Se2:正交、Pn a = 415.46(2), b = 894.29(5), c = 1160.14(7) pm)。这些结构不是同型的,显示出不同的分子堆积,其对称性仅略微偏离 D2h。在四元 C4 环中,CC 键代表一个单键、一个双键和两个稍微缩短的单键。C4 环因此被认为是环丁烯二酮片段。加热至 220 至 240 °C 时发生的化合物剧烈放热分解表明两者都是含能材料。爆炸伴随着 C8O4S2 的 -192 kJ/mol 和 C8O4Se2