Template-directed Synthesis of Three Metal Oxalates via 4-Connected Building Units

Three novel compounds, [Co（en）3]2[Zr2（C2O4）7]·2H20（HNU-2, en=ethylenediamine）, [Co（NH3）6]· [Ce（CzO4）3（H2O）]·H2O（HNU-3） and [Co（dien）2][Gd（C2On）3]·0.75H2O（HNU-4, dien=dethylenetriamine） were hydro- thermal synthesized based on the templates of [Co（en）3]C13, [C0（NH3）6]C13 and [Co（dien）2]C13, respectively. The Zr4＋ Ce3＋ and Gd3＋ cations are all coordinated by four oxalates to form [M（C2O4）n（H2O）n]m （M=Zr, Ce or Gd; n=0 or 1; m=4 or 5）, which are similar to [In（C2O4）4]5- in NKB-1, and can be regarded as 4-connected building units. The [M（C2O4）a（H2O）n]m units are connected via sharing the bis-bidentate bridging oxalate ligands to form binuclears in HNU-2 and 1D ＂zigzag＂ chains in HNU-3 and HNU-4. cular building units to design 3D open frameworks with It is suggested that these compounds could be used as mole- zeolite topologies.

S-doped porous carbon fibers with superior electrode behaviors in lithium ion batteries and fuel cells

The orientation construction of S-doped porous carbon fibers(SPCFs)is realized by the facile template-directed methodology using asphalt powder as carbon source.The unique fiber-like morphology without destruction can be well duplicated from the template by the developed methodology.MgSO4 fibers serve as both templates and S dopant,realizing the in-situ S doping into carbon frameworks.The effects of different reaction temperatures on the yield and S doping level of SPCFs are investigated.The S doping can not only significantly enhance the electrical conductivity,but also introduce more defects or disorders.As anode material for lithium ion batteries(LIBs),SPCFs electrode delivers better rate capability than undoped PCFs.And the capacity of SPCFs electrode retains around 90%after 300 cycles at 2 A g
1,exhibiting good cycling stability.As the electrocatalysts for fuel cells,the onset potentials of SPCFs obtained at 800 and 900C are concentrated at 0.863 V,and the higher kinetic current densities at 0.4 V of them are larger than that of PCFs,demonstrating the superior electrocatalytic performance.Due to the synergistic effect of abundant pore channels and S doping,SPCFs electrode exhibits superior electrochemical performances as anode for LIBs and elecctrocatalyst for fuel cells,respectively.Additionally,the oriented conversion of asphalt powder into high-performance electrode material in this work provides a new way for the high value application of asphalt.

The cage effect on assembly of cyclic-bis-(zinc porphyrin) with 5,15-dipyridylporphyrin

An inclusion complex of cyclic bis(zinc porphyrin) 1 with 5,15-dipyridylporphyrin derivative 3 has been designed and constructed. The complex formation is induced by Zn-N coordination, and is robust (Kassoc ~ 106 L/mol) due to the presence of the cage effect of cyclic bis(zinc porphyrin). The cage-like complex as an entity is stable enough, and also convenient to achieve relative movement between the bis(zinc porphyrin) host and the dipyridylporphyrin guest connected by Zn-N coordination. The characteristics of these assemblies have been demonstrated by 1 H NMR, UV-vis, and fluorescence spectra. The results show its potential applications as a molecular gyroscope in molecular machines.