以邻菲咯啉衍生物及1，3-间苯二甲酸为配体的一维链状Cd(Ⅱ)配位聚合物的合成及结构

在水热条件下,我们利用邻菲咯啉衍生物配体(L=2-(3-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline)和1,3-间苯二甲酸(1,3-H2BDC)反应得到了一维配位聚合物[Cd2(L)2(1,3-BDC)2]n,并对该化合物进行了元素分析、红外和单晶X-射线表征。该化合物属于三斜晶系,空间群Pī,晶胞参数a=1.080 8(4)nm,b=1.149 5(4)nm,c=1.924 8(7)nm,α=106.482(5)°,β=99.436(6)°,γ=93.093(6)°,V=2 249.2(14)nm3,Z=4,C27H15CdFN4O4,Mr=590.83,Dc=1.745 g.cm-3,F(000)=1 176,μ(Mo Kα)=1.024 mm-1,R=0.044 5和wR=0.111 7。该化合物为一维链状结构,链与链之间又进一步地通过CH-π相互作用形成二维层状超分子结构。     

Revisions of P-1 Space Groups to Higher Symmetry Space Groups

The space groups of 244 crystal structures originally reported as P-1 are revised to space groups of higher symmetry. The largest number involves revisions to P2/c and C2/c.     

Revising Space Groups from Simulated SHELX·fcf Structure Factors. More Examples of Incorrect Space Groups, an Example of a Chemically-Incorrect Structure and the Special Case of P1 to P(-1) Revisions

The structure factors of any crystal structure can be simulated from its atomic coordinates (and temperature factors) in a SHELXL-97 run on a dummy hkl in which only the scale factor is refined. The squares of the structure factors are retrieved from thefcf, and such simulated data are used in the revision of the space groups of several incorrectly-refined crystal structures. Two cases, a P1 to Pl- revision and a chemically-incorrect structure that is refined in a correct space group, are discussed.     

双(二吡啶胺)配体的二维和三维超分子配位聚合物的合成与晶体结构

从含4,4'-二吡啶胺结构单元的双(二吡啶胺) 桥联配体出发,采用溶剂热法合成了两个结构新颖的配位聚合物：[CdL1Br2]n?7.5nH2O (L1 = N,N,N′,N′-四(4-吡啶)-1,4-苯二胺) (1)和[Cu2L2(μ1,1,3-SCN)2]n?nMeOH (L2 = N,N-二(2-吡啶)-N',N'-二(4-吡啶)-1,4-苯二胺) (2),对它们进行了元素分析、红外光谱等表征,并用X-射线单晶衍射测定了其晶体结构。单晶测试结果显示,配合物1中配体L1的四个吡啶N原子均参与配位,桥联了4个Cd原子,每个Cd原子与四个吡啶 N 原子和两个溴配位,形成六配位的八面体构型。通过这些配位作用,最终形成包含 Kagome 结构的三维超分子网络。配合物2 是由一维柱状 {Cu(SCN)}n 链通过 L2 桥联生成的二维结构。有趣的是,L2中具有螯合能力的2,2'-二吡啶胺单元并未参与配位,只有4,4'-二吡啶胺单元中的两个吡啶N原子分别与一个 Cu(I) 配位,连接了相邻两条平行的{Cu(SCN)}n 链,生成二维结构。