A new cobalt compound,{[Co（H2btec）（2,2＇-bipy）（H2O）3]·H2O}n （1,H4btec=1,2,4,5-benzenetetracarboxylic acid,2,2＇-bipy=2,2＇-bipyridine）,has been synthesized and charac-terized by single-crystal X-ray diffraction,elemental analysis,IR and X-ray powder diffraction.The crystal belongs to the triclinic system,space group P1,with a=7.230（3）,b=11.626（5）,c=14.001（6）,α=108.12（0）°,β=95.85（0）°,V=1095.33（157）3,C20H20CoN2O12,Mr=539.31,Z= 2,Dc=1.635 g/cm3,μ=0.855 mm-1,F（000）=554,R=0.0427 and wR=0.1042 for 3883 observed reflections （I 〉 2σ（I））.The title compound features a discrete molecular structure,which is connected with each other through extensive O-H…O hydrogen bonds into an intricate 3D supramolecular network.Additionally,two different patterns of π-π stacking interactions further consolidate the framework.
Solvothermal reactions of 1,3,5-benzenetricarboxylic acid (H3btc) with cadmium acetate or zinc acetate yielded two compounds formulated as (Me2NH2)[Cd(btc)]·DMA (1) (btc = 1,3,5-benzenetricarboxylate, DMA = N,N-dimethylacetamide) and (Me2NH2)[Zn(btc)]·DMF (2) (DMF = N,N-dimethylformamide). Both are 3-D frameworks with the rutile topology, which are constructed from six-connected dimeric metal cores and three-connected btc linkers. The solvent molecules and counter cations are located in the 1-D channels of the frameworks. A slight difference between the two compounds is the different connectivity modes of the metal atoms with the carboxylate groups of the ligands. However, this slight difference results in distinct flexibilities of the two frameworks. Variable-temperature powder X-ray diffraction studies revealed that the framework of 1 collapses when heated at 180 °C with loss of the guest species, but compound 2 undergoes two structural transformations below 380 °C. Thermogravimetry-infrared spectroscopy analysis for 2 showed that the two structural transformations are induced by separate losses of solvent molecules and counter cations, and that the dimethylammonium cations are eliminated as neutral dimethylamine molecules. IR spectroscopy demonstrated that the protons are transferred from the counter cations onto the uncoordinated carboxylate oxygen atoms on the channel walls. Sorption and proton conduction studies have also been performed for the compounds.
XIE LinHua1, LIN JianBin1, LIU XiaoMin1, XUE Wei1, ZHANG WeiXiong1, LIU ShuXia2, ZHANG JiePeng1 & CHEN XiaoMing1 1MOE Key Laboratory of Bioinorganic and Synthetic Chemistry
A novel zinc coordination polymer, [Zn2（bptc）（bpe）（H2O）]n （1, Habptc = 3,3＂,4,4＂- benzophenonetetracarboxylate, bpe = 1,2-bis（4-pyridyl） ethane）, has been prepared under hydrothermal conditions. The crystal structure is of monoclinic, space group C/2c with a = 27.50（2）, b = 6.207（4）, c = 16.233（11） A, β = 107.522（14）°, V= 2642 （3） As, C29H22N2O11Zn2, Mr = 705.27, Z = 4, Dc = 1.773 g/cm3, F（000） = 1432, p = 1.887 mm-1, R = 0.0421 and wR = 0.1049 for 2594 observed reflections （I 〉 20（/））. X-ray single-crystal diffraction analysis shows that 1 features two-dimensional [Zn2（bptc）（H2O）] layers, which are further linked by the bpe ligands to give rise to a three-dimensional pillar-layered structure. According to the topology analysis, this framework can be simplified into a （4,6）-connected （4^4.6＆2）（4^4.6^10.8） network.
A new neutral [Ag2（Hida）（NH3）2] molecule （1, H3ida = 1H-imidazole-4,5-dicarboxylic acid） has been synthesized and structurally characterized by single-crystal diffraction. Compound 1 crystallizes in monoclinic, space group C2/c with a = 18.3928（8）, b = 8.3299（5）, c = 13.682（7） A, β = 113.179（2）°, V = 1926.9（10）A^3, Z = 8 and Dc = 2.784 g·cm^-3. In the solid state, this disilver（I） compound can aggregate to furnish the energetically stable ligand-unsupported Ag^I-Ag^I interaction concomitant with significant photoluminescence changes in different aggregate states, and such argentophilicity interaction is also supported by molecular orbital calculations.
