含八面体笼结构及具有新颖配位方式的2,3-吡嗪二甲酸钡、钙配合物的晶体结构

Crystal Structure of Barium and Calcium 2,3-Pyrazinedicarboxylate Complexes Containing an Octahedral Cage Structure and a Novel Coordination Mode

以2,3-吡嗪二甲酸(2,3-H2pzdc)分别与硝酸钡及硝酸钙反应,首次得到了具有八面体笼结构的2,3-吡嗪二甲酸钡配位聚合物[Ba(pzdc)(H2O)](1)和具有新颖配位方式的2,3-吡嗪二甲酸钙配位聚合物[Ca(pzdc)(H2O)2]·H2O(2)晶体.晶体(1)中钡离子的配位数为9,为二维层状结构,属单斜晶系,Ba2+和羧基氧原子形成一个八面体的笼结构,晶胞参数a,b,c分别为12.5877(16)?,9.4055(12)?,7.1013(9)?.钡离子与2,3-吡嗪二甲酸的配位方式:O1、C1、C2、N2与Ba2+形成五元螯合环;O2、O4、C1、C2、C3、C10与Ba2+形成七元环,且O2桥联两个钡离子。晶体(2)中钙离子的配位数为8,也为二维层状结构,单斜晶系,晶胞参数a,b,c分别为8.4241(17)?,16.782(4)?,6.9061(14)?。钙离子与2,3-吡嗪二甲酸的配位方式:N1、C3、C5、O1与Ca2+形成五元环;O3、O4、C6与Ca2+形成四元环,且同一羧基的两个氧原子O3、O4分别桥联两个钙离子。在这两个配合物中,出现了pzdc2-的两种新颖的未见报道的配位方式。

For the first time,a 2,3-pyrazine barium dimethylate coordination polymer with an octahedral cage structure([Ba(pzdc)(H2 O)](1))and a 2,3-pyrazine calcium dimethylate coordination polymer with a novel coordination mode([Ca(pzdc)(H2 O)2]·H2 O(2))were synthesized via the reaction of 2,3-pyrazine dimethyl acid(2,3-H2 pzdc)with barium nitrate and calcium nitrate,respectively.The coordination number of Ba2+in polymer(1)is 9 andexhibits a two-dimensional layered structure with a monoclinic system,and Ba2+and carboxy-oxygen atoms form an octahedral cage structure,with the cell parameters of a,b,and c at 12.5877(16)?,9.4055(12)?,and 7.1013(9)?,respectively.The coordination of Ba2+with O1,C1,C2,N2 of 2,3-pyrazine dimethyl acid forms a five-membered chelation ring;while the coordination of Ba2+with O2,O4,C1,C2,C3,C10 of 2,3-pyrazine dimethyl acid forms a seven-membered ring.The O2 behaviors a bridge to connect two Ba2+.The coordination number of Ca2+in polymer(2)is 8 and also exhibits a two-dimensional layered structure with a monoclinic system and the cell parameters a,b,and c are 8.4241(17)?,16.782(4)?,and 6.9061(14)?,respectively.The coordination of Ca2+with N1,C3,C5,O1 of 2,3-pyrazine dimethyl acid forms a five-membered ring;while the coordination of Ca2+with O3,O4,C6 and Ca2+forms a four-membered ring with two oxygen atoms of O3 and O4 on the same carboxyl group to bridge two Ca2+,respectively.In these two complexes,two novel unreported coordination modes of pzdc2-are found.