Bryndal I, Lorenc J, Macalik L, Michalski J, Sąsiadek W, Lis T, Hanuza J
Department of Drugs Technology, Faculty of Pharmacy with Division of Laboratory Diagnostics, Wroclaw Medical University, Borowska 211A, 50-556, Wrocław, Poland.
Department of Bioorganic Chemistry, Institute of Chemistry and Food Technology, Faculty of Engineering and Economics, Wrocław University of Economics, Komandorska 118/120, 53-345, Wrocław, Poland.
J Mol Struct. 2019 Nov 5;1195:208-219. doi: 10.1016/j.molstruc.2019.05.064. Epub 2019 May 24.
The crystal and molecular structure and physicochemical properties of 2--methylamino-3-methylpyridine -oxide (MA3MPO) have been studied. MA3MPO was synthesized from 2-amino-3-methylpyridine by several steps to form colorless crystals suitable for crystallographic analysis. The data reveal that MA3MPO crystallizes in the monoclinic space group 2/. The studied compound contains a nearly flat triply substituted pyridine skeleton whose structure is stabilized by an intramolecular N-H⋅⋅⋅O hydrogen bond. The N-oxide molecules are connected together by weak C-H⋯O hydrogen bonds, an acceptor of which is the oxygen atom from the N-oxide group. This leads to creation of two-dimensional network of hydrogen bonds. Its IR, Raman, UV-Vis and luminescence spectra have been measured and analyzed on the basis of DFT and NBO quantum chemical calculations in which the B3LYP/6-311++G(d,p) approach was applied. The distribution of the electron levels in the studied compound has been analyzed in terms of the possibility of its participation in the ligand-to-lanthanide ion energy transfer.
对2-甲氨基-3-甲基吡啶-N-氧化物（MA3MPO）的晶体与分子结构及物理化学性质进行了研究。MA3MPO由2-氨基-3-甲基吡啶经多步合成得到适合晶体学分析的无色晶体。数据表明MA3MPO结晶于单斜空间群2/。所研究的化合物含有一个近乎平面的三取代吡啶骨架，其结构通过分子内N-H⋅⋅⋅O氢键得以稳定。N-氧化物分子通过弱C-H⋯O氢键连接在一起，该氢键的受体是N-氧化物基团中的氧原子。这导致形成二维氢键网络。基于密度泛函理论（DFT）和自然键轨道（NBO）量子化学计算（采用B3LYP/6-311++G(d,p)方法）对其红外光谱、拉曼光谱、紫外可见光谱和发光光谱进行了测量与分析。根据该化合物参与配体到镧系离子能量转移的可能性，对其电子能级分布进行了分析。
