双齿甜菜碱衍生物大环及双环镉(Ⅱ)配位化合物的合成与晶体结构

利用甜菜碱衍生物1,5-二(4-羧基吡啶基)-N-甲基二乙胺(L)合成了两种镉(Ⅱ)的配位化合物[Cd2Cl4(H2O)2L2].2H2O和[Cd2(SCN)4(μ-H2O)L2]。用X-射线单晶衍射仪测定了配合物的单晶结构,并对它们进行了元素分析、红外光谱、1H NMR、热重等表征。结构分析表明,前者具有三十六元大环框架,而后者为双环结构。由于缺乏分子之间的强烈相互作用,弱相互作用决定了这两种化合物在晶格中的堆积模式:前者由相邻分子间的π-π和C-H…π相互作用而堆积形成二维砖墙的结构;后者由配位的SCN-阴离子通过S…S弱相互作用联接成一维链状结构。

Synthesis and Crystal Structures of Cadmium(H) Coordination Compounds of Large Ring and Bicyclo Framework with a Bidentate Betaine Derivative

A new bidentate betaine derivative 1,5-bis(4-carboxypyridinium)-N-methyl-diethylamine(L) was prepared and allowed to react with cadmium salts leading to the formation of two new cadmium coordination compounds [Cd2Cl4(H2O)2L2]·2H2O and [Cd2(SCN)4(μ-H2O)L2],which were structurally characterized by IR spectoroscopy,single-crystal X-ray diffraction,elemental analysis,thermal analysis,etc.The single crystal X-ray diffraction structure analysis of these compounds shows the molecule of former consists of discrete 36-membered ring and that of latter bicyclo[17.17.1] structure.Owing to lacking strong intermolecular interactions in these compounds,weak interactions determine their packing pattern in crystalline state: the former forms 2D brick-wall network by the π-π stacking and C-H…π interactions between pyridyl rings of adjacent molecules,and the latter zig-zag chains through S…S weak interactions between ligating SCN-anions.CCDC: 860582,1;860583,2.