Hydrothermal reaction of La2O3, Zn(CH3COO)2 · 2H2O and pyridine-2, 5-dicarboxylic acid (H2pydc) in waterrngave rise to a La (Ⅲ)-Zn (Ⅱ) coordination polymer, [La2Zn2(pydc)5(H2O)2] n(1), which crystallizes in monoclinicrnspace group P21/c with a =9.5869(1), b =20. 4862(3), c= 10. 1105(2) A, β=97. 4890(10)°, V= 1968.76rn(5)A3, Z = 4. However, under the same condition, hydrothermal reaction of Er2O3 or Tb4O7, Zn(CH3COO)2 · 2H2Ornand H2pydc resulted in the formation of a polymer [Ln2Zn(pydc) 4(H2O) 8 · H2O] n(Ln = Er(2); Ln= Tb(3)) .rnCompound 2 and 3 are isomorphous and crystallize in triclinic space group P-1 with a = 7.8708 (7), b = 9. 2665rn(8), c=13.0232(11)A, α=75.295(1),3=75.000(2), y=79. 109(2)°, V=879.67(13)A3,Z=1 for2, andrna =7.9105(5), b =9. 3453(6), c = 13.0005(9) A, α =75. 3380(10), β=75. 0460(10), γ =79.0050(10)°,rnV = 890. 17 (10)A3, Z = 1 for 3. All polymers have been characterized by single crystal X-ray diffraction analyses.rn1 displays a three-dimensional network structure, while the crystal structure of 2 and 3 possess a tubule shapernstructure. Thermal gravimetric analysis studies of 1 and 2 display that the frameworks of the all compounds existrnstably below 380℃ although the discrete and coordination water molecules lost in the range of 50 ～ 260℃.%Gd2O3,Zn(CH3COO)2·2H2O和吡啶-2,5-二羧酸(H2pydc)的水热反应导致一个新颖的钆-锌配位聚合物[La2Zn2(pydc)5(H2O)2]n(1).化合物1的晶体属单斜晶系,空间群P21/c,a=9-5869(1), b=20.4862(3), c=10.1105(2)A,β=97.4890(10)°,V=1968.76(5)A3,Z=4.在同样的条件下,Er2O3或Tb4O7,Zn(CH3COO)2·2H2O和H2pydc的水热反应产生了与化合物1结构不同的配位聚合物[Ln2Zn(pydc)4(H2O)8·H2O]n(Ln=Er(2); Ln=Tb(3)).化合物2和3异质同晶,空间群P1.对2:a=7.8708(7), b=9.2665(8), c=13.0232(11)A, α=75.295(1),β=75.000(2),γ=79.109(2)°,V=879.67(13)A3,Z=1; 对3:a=7.9105(5), b=9.3453(6), c=13.0005(9)A, α=75.3380(10),β=75.0460(10), γ=79.0050(10)°,V=890.17(10)A3,Z=1.X-射线单晶结构研究表明化合物1是一个三维网状结构,而化合物2和3为管状结构.热重分析研究表明所有化合物在380℃以下稳定.
展开▼
