Okuniewski Andrzej, Rosiak Damian, Chojnacki Jarosław
Department of Inorganic Chemistry, Chemical Faculty, Gdańsk University of Technology, G. Narutowicza 11/12, 80-233 Gdańsk, Poland.
Acta Crystallogr C Struct Chem. 2020 May 1;76(Pt 5):468-475. doi: 10.1107/S2053229620005525. Epub 2020 Apr 24.
By the reaction of urea or thiourea, acetylacetone and hydrogen halide (HF, HBr or HI), we have obtained seven new 4,6-dimethyl-2-pyrimido(thio)nium salts, which were characterized by single-crystal X-ray diffraction, namely, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium bifluoride, CHNO·HF or (dmpH)FH, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium bromide, CHNO·Br or (dmpH)Br, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium iodide, CHNO·I or (dmpH)I, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium iodide-urea (1/1), CHNO·I·CHNO or (dmpH)I·ur, 4,6-dimethyl-2-sulfanylidene-2,3-dihydropyrimidin-1-ium bifluoride-thiourea (1/1), CHNS·HF·CHNS or (dmptH)FH·tu, 4,6-dimethyl-2-sulfanylidene-2,3-dihydropyrimidin-1-ium bromide, CHNS·Br or (dmptH)Br, and 4,6-dimethyl-2-sulfanylidene-2,3-dihydropyrimidin-1-ium iodide, CHNS·I or (dmptH)I. Three HCl derivatives were described previously in the literature, namely, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium chloride, (dmpH)Cl, 4,6-dimethyl-2-sulfanylidene-2,3-dihydropyrimidin-1-ium chloride monohydrate, (dmptH)Cl·HO, and 4,6-dimethyl-2-sulfanylidene-2,3-dihydropyrimidin-1-ium chloride-thiourea (1/1), (dmptH)Cl·tu. Structural analysis shows that in 9 out of 10 of these compounds, the ions form one-dimensional chains or ribbons stabilized by hydrogen bonds. Only in one compound are parallel planes present. In all the structures, there are charge-assisted N-H...X hydrogen bonds, as well as weaker C-H...X and π...X interactions. The structures can be divided into five types according to their hydrogen-bond patterns. All the compounds undergo thermal decomposition at relatively high temperatures (150-300 °C) without melting. Four oxopyrimidinium salts containing a π...X...π sandwich-like structural motif exhibit luminescent properties.
通过尿素或硫脲、乙酰丙酮与卤化氢（HF、HBr或HI）的反应，我们得到了七种新的4,6 - 二甲基 - 2 - 嘧啶（硫）鎓盐，通过单晶X射线衍射对其进行了表征，即4,6 - 二甲基 - 2 - 氧代 - 2,3 - 二氢嘧啶 - 1 - 鎓二氟化物，CHNO·HF或(dmpH)FH，4,6 - 二甲基 - 2 - 氧代 - 2,3 - 二氢嘧啶 - 1 - 鎓溴化物，CHNO·Br或(dmpH)Br，4,6 - 二甲基 - 2 - 氧代 - 2,3 - 二氢嘧啶 - 1 - 鎓碘化物，CHNO·I或(dmpH)I，4,6 - 二甲基 - 2 - 氧代 - 2,3 - 二氢嘧啶 - 1 - 鎓碘化物 - 尿素（1/1），CHNO·I·CHNO或(dmpH)I·ur，4,6 - 二甲基 - 2 - 硫亚基 - 2,3 - 二氢嘧啶 - 1 - 鎓二氟化物 - 硫脲（1/1），CHNS·HF·CHNS或(dmptH)FH·tu，4,6 - 二甲基 - 2 - 硫亚基 - 2,3 - 二氢嘧啶 - 1 - 鎓溴化物，CHNS·Br或(dmptH)Br，以及4,6 - 二甲基 - 2 - 硫亚基 - 2,3 - 二氢嘧啶 - 1 - 鎓碘化物，CHNS·I或(dmptH)I。文献中先前已描述了三种HCl衍生物，即4,6 - 二甲基 - 2 - 氧代 - 2,3 - 二氢嘧啶 - 1 - 鎓氯化物，(dmpH)Cl，4,6 - 二甲基 - 2 - 硫亚基 - 2,3 - 二氢嘧啶 - 1 - 鎓氯化物一水合物，(dmptH)Cl·HO，以及4,6 - 二甲基 - 2 - 硫亚基 - 2,3 - 二氢嘧啶 - 1 - 鎓氯化物 - 硫脲（1/1），(dmptH)Cl·tu。结构分析表明，在这些化合物中的10个中有9个，离子形成通过氢键稳定的一维链或带。仅在一种化合物中存在平行平面。在所有结构中，存在电荷辅助的N - H...X氢键以及较弱的C - H...X和π...X相互作用。根据它们的氢键模式，结构可分为五种类型。所有化合物在相对较高的温度（150 - 300 °C）下发生热分解而不熔化。四种含有π...X...π夹心样结构基序的氧代嘧啶鎓盐表现出发光特性。
