The hydrothermal reaction of Zn（NO3）2·4H2O, cyclohexane-1,2,3,4,5,6-hexacarboxylic acid hydrate （H6LI·H2O, cis-conformation LI： a,e,a,e,a,e） and 2,2＇-bpy yielded a new coordination polymer [Zn2（H2LII）（2,2＇-bpy）]·2H2O（trans-conformation LII： e,e,e,e,e,e）, which was characterized by single-crystal X-ray diffraction, elemental analysis, IR and XRPD（X-ray powder diffraction）. This complex crystallized in the triclinic system, with P1 space group and parameters a=0.66922（5） nm, b=0.97291（8） nm, c=1.22184（9） nm, α=99.0020（10）°, β=99.1300（10）°, γ=99.1910（10）°, V= 0.76176（10） nm3 and Z=2. The structure is a three-dimensional supramolecular network based on linear coordination chains through π-π stacking and hydrogen bonding interactions. The confromation of the starting ligand H6LI transfromed to the H2LII. The complex emits strong luminescence at room temperature.
The hydrothermal reactions of Ni（Ⅱ）, 1,2,3-benzenetricarboxylic acid （1,2,3-H3btc） and 4,4＇-bipyfidine （4,4＇-bpy）/1,2-bis（4-pyridyl）ethane （bpa） yield two layered nickel（II） coordination polymers, [Ni2（l,2,3-btc）（OAc）- （4,4＇-bpy）2（H20）]o2H2O （1） and [Ni（ip）（bpa）] （2） （ip=isophthalate）, respectively. Both complexes are 2-D coordi- nation network based on 1-D Ni-carboxylate chains. The 1,2,3-btc ligand adopts 3-bridging mode in complex 1, but transformed to isophthalate （ip） ligand through decarboxylation in 2. The formation of the two complexes indicates that hydrothermal conditions and in-situ ligand reaction have significant effect on constructing coordination polymers.
The hydrothermal reaction of Cd（OAc）2·2H2O, 4,4＇-bpy and cyclohexane-1,2,4,5-tetracarboxylic acid （H4L） yields a three-dimensional （3D） coordination porous framework [Cd2LI（4,4＇-bpy）1.5（H2O）2]n·2nH2O, which was characterized by single-crystal X-ray diffraction （MoKα radiation, λ = 0.71073）, elemental analysis and IR. This complex crystallizes in the monoclinic system, space group C2/c with a = 25.951（3）, b = 11.6618（12）, c = 20.046（2） A, β = 114.863（2）o, V = 5504.4（10）A^3, Z = 8, Dc = 1.900 g/cm^3, Mr = 787.30, μ = 1.615 mm^-1, F（000） = 3128, the final R = 0.0978 and wR = 0.1780. The structure of the complex is a 3D coordination Cd-carboxylate framework consisting of 1D hexagonal channels along the c-axis filled with the bridging 4,4＇-bpy ligands. The 4,4＇-bpy ligands with two kinds of conformations are located alternately in the channels through coordination and hydrogen interactions to support the whole porous framework, in which the conformation-flexible cyclohexane-1,2,4,5-tetracarboxylate ligand adopts the I （e,a,a,e） conformation and acts as a pentadentate ligand to connect five Cd（Ⅱ） atoms via the carboxylate groups in different coordination modes.
