The title complexes（NH4）[Ag（dpe）（H2bptc）]（1） and Ag2（bpy）（ox）·7H2O（2） were synthesized via slow evaporation at room temperature,and characterized by elemental analysis and infrared spectra.The crystal of 1 crystallizes in triclinic,space group P1 with a = 8.3959（7）,b = 11.8088（12）,c = 12.8175（13） ,α = 85.507（2）,β = 79.245（1）,γ = 84.174（2）o,V = 1239.7（2） 3,Z = 2,C28H22AgN3O8,Mr = 636.36,Dc = 1.705 g/cm3,F（000） = 644 and μ（MoKα） = 0.874 mm-1.The final R = 0.0479 and wR = 0.1426 for 3632 observed reflections with I 〉2σ（I） and R = 0.0559 and wR = 0.1503 for all data.The crystal of 2 crystallizes in orthorhombic,space group Pnna with a = 17.2291（17）,b = 7.5289（6）,c = 21.369（2）,V = 2771.9（4） 3,Z = 4,C22H30Ag2N4O11,Mr = 742.24,Dc = 1.779 g/cm3,F（000） = 1488 and μ（MoKα） = 1.476 mm-1.The final R = 0.0648 and wR = 0.2058 for 1996 observed reflections with I 〉2σ（I） and R = 0.0769 and wR = 0.2192 for all data.X-ray diffraction reveals that in complexes 1 and 2,both 1,2-di（4-pyridyl）ethylene and 4,4＇-bipyridine act as typical bidentate N-donor ligands to link two Ag centers.3,3＇4,4＇-Biphenyltetracarboxylate and oxalate anions play the role of organic linkers and counter-ions to balance the cationic charge of AgI.The rich hydrogen-bonding interactions and ligand-unsupported Ag…Ag interactions as well as π-π stacking interactions contribute to the construction of three-dimensional sandwich-like frameworks.
In this work,calcium-strontium apatite (Sr-HA) hollow nanospheres were synthesized by a facile biomimetic method.The structure and property of Sr-HA were characterized by FESEM,TEM,HRTEM,XRD and FT-IR spectroscopy.The influences of different ratios of calcium and strontium on the morphologies of the Sr-HA products were investigated.The experimental results revealed that the hollow spherical Sr-HA,with a size of 30-120 nm in diameter,could be synthesized when the molar ratio of Ca/Sr was 1:1.The possible formation mechanism of the hollow Sr-HA was proposed.The drug release experiments indicated that the hollow spherical Sr-HA had the property of sustained release.
GAN Yong,HAN DongMei,GU FuBo,WANG ZhiHua & GUO GuangSheng State Key Laboratory of Chemical Resource Engineering,Beijing University of Chemical Technology,Beijing 100029,China
