Zhao Zhou, He Xiang, Zhao Yongmei, Shao Min, Zhu Shourong
Department of Chemistry, College of Science, Shanghai University, Shanghai, 200444, China.
Dalton Trans. 2009 Apr 21(15):2802-11. doi: 10.1039/b813167h. Epub 2009 Feb 23.
4,4'-Bipyridine-2,6,2',6'-tetracarboxylic acid H4L.3H2O, () and its copper(II) and cobalt (II) coordination polymers [Cu2L(H2O)4]2n () and {[Co(H2O)6].[Co3L2(H2O)2].10H2O}3n () have been hydrothermally synthesized. Compound packs into a crystal via H-bonds. Complex is a 2D coordination grid, in which Cu is in an elongated octahedral constructed by a mer-geometry pyridyl-2,6-dicarboxylate, one bridging carboxylate oxygen and two water molecules. The L4- is central symmetrical. Each pyridyl-2,6-dicarboxylate chelete to Cu(II) and one carboxylate bridge Cu(II) ions in a 1,1-fashion. The 2D coordination polymer links to adjacent layers via H-bonds. Complex is a metal-organic framework with 11.6x10.5 A rectangular channels. All Co(II) ions are located in an octahedral coordination environment. The rectangular channels are composed of Co2+-L4- walls and the walls are linked through carboxylate oxygen atoms and Co(II) ions. Co(H2O)6(2+) as counter ions fill in porous channel. The removal of water molecules from at 210 degrees C or higher affords the porous material [Co4L2]n, which can adsorb 16 (36%) methanol or 9 (32%) ethanol in the vapour phase. The porosity of is higher than reported 4,4'-bipyridine-2,6,2',6'- tetracarboxylate complexes. The framework of remains but the crystallinity is lost upon removal of the H2O molecules. The dehydrated framework of partially recovery crystallinity after it adsorbs H2O, CH3OH and C2H5OH. The methanol in the framework can be replaced by H2O reversibly.
4,4'-联吡啶-2,6,2',6'-四羧酸H4L·3H2O()及其铜(II)和钴(II)配位聚合物[Cu2L(H2O)4]2n()和{[Co(H2O)6]·[Co3L2(H2O)2]·10H2O}3n()已通过水热法合成。化合物通过氢键堆积成晶体。配合物是二维配位网格,其中Cu处于由间位几何结构的吡啶-2,6-二羧酸酯、一个桥连羧酸根氧和两个水分子构成的拉长八面体中。L4-是中心对称的。每个吡啶-2,6-二羧酸酯以1,1-方式螯合到Cu(II)上,一个羧酸根桥连Cu(II)离子。二维配位聚合物通过氢键连接到相邻层。配合物是具有11.6×10.5 Å矩形通道的金属有机框架。所有Co(II)离子都位于八面体配位环境中。矩形通道由Co2+-L4-壁组成,壁通过羧酸根氧原子和Co(II)离子相连。Co(H2O)6(2+)作为抗衡离子填充在多孔通道中。在210℃或更高温度下除去水分子得到多孔材料[Co4L2]n,其在气相中可吸附16(36%)甲醇或9(32%)乙醇。其孔隙率高于报道的4,4'-联吡啶-2,6,2',6'-四羧酸酯配合物。除去H2O分子后,框架保留但结晶度丧失。脱水框架在吸附H2O、CH3OH和C2H5OH后部分恢复结晶度。框架中的甲醇可被H2O可逆取代。