Department of Chemistry, Indian Institute of Technology, Kanpur, 208016 India.
Chemistry. 2010 May 3;16(17):5070-7. doi: 10.1002/chem.200903129.
The porous coordination polymer ({Mn(L)H(2)O(1.5)(dmf)}(n), 1) (DMF=N,N-dimethylformamide) exhibits variety of substitution reactions along with movement of lattice DMF molecule depending upon bulkiness of the external guest molecules. If pyridine or 4-picoline is used as a guest, both lattice and coordinated solvent molecules are simultaneously substituted (complexes 6 and 7, respectively). If a bulky guest like aniline is used, a partial substitution at the metal centers and full substitution at the channels takes place (complex 8). If the guest is 2-picoline (by varying the position of bulky methyl group with respect to donor N atom), one Mn(II) center is substituted by 2-picoline, whereas the remaining center is substituted by a DMF molecule that migrates from the channel to the metal center (complex 9). Here, the lattice solvent molecules are substituted by 2-picoline molecules. For the case of other bulky guests like benzonitrile or 2,6-lutidine, both the metal centers are substituted by two DMF molecules, again migrating from the channel, and the lattice solvent molecules are substituted by these guest molecules (complex 10 and 11, respectively). A preferential substitution of pyridine over benzonitrile (complex 12) at the metal centers is observed only when the molar ratio of PhCN:Py is 95:5 or less. For the case of an aliphatic dimethylaminoacetonitrile guest, the metal centers remain unsubstituted (complex 13); rather substitutions of the lattice solvents by the guest molecules take place. All these phenomena are observed through single crystal to single crystal (SC-SC) phenomena.
多孔配位聚合物(Mn(L)H2O(1.5)(dmf))(n)(1)(DMF=N,N-二甲基甲酰胺)表现出多种取代反应,同时伴随着晶格 DMF 分子的运动,这取决于外部客体分子的体积。如果使用吡啶或 4-吡啶作为客体,晶格和配位溶剂分子都会同时被取代(分别为配合物 6 和 7)。如果使用像苯胺这样的大体积客体,金属中心会发生部分取代,而通道则会完全取代(配合物 8)。如果客体是 2-吡啶(通过改变大体积甲基相对于供体 N 原子的位置),一个 Mn(II)中心被 2-吡啶取代,而其余中心被从通道迁移到金属中心的 DMF 分子取代(配合物 9)。在这里,晶格溶剂分子被 2-吡啶分子取代。对于其他大体积客体,如苯甲腈或 2,6- 吡啶,两个金属中心都被两个 DMF 分子取代,再次从通道迁移,晶格溶剂分子被这些客体分子取代(分别为配合物 10 和 11)。只有当 PhCN:Py 的摩尔比为 95:5 或更小时,才会观察到吡啶对苯甲腈(配合物 12)在金属中心的优先取代。对于脂肪族二甲基氨基乙腈客体,金属中心保持未取代(配合物 13);相反,晶格溶剂被客体分子取代。所有这些现象都是通过单晶到单晶(SC-SC)现象观察到的。