Two chiral supramolecular porous solids derived from novel cluster-based structures of [Mn^Ⅲ_4Mn^Ⅱ] and [Mn_7^Ⅲ Mn_3^Ⅱ ] were synthesized. Driven by the distinct pores and host-guest interactions, they exhibited either selective gas adsorption ability for the former or the ability of enan- tioselective separation via reversible single-crystal-to-sin- gle-crystal transformation for the latter.
Dielectric anisotropy of anilinium perchlorate is investigated at various temperatures. Crystal structures at different temperatures reveal that significant dielectric change between low and high dielectric states is closely related to the disorder of the anilinium cation and perchlorate anion at high dielectric state; meanwhile, the conductivity after phase transition also contributes a lot to the high dielectric state.
DU YangHAO HuiMinZHANG QianChongZHAO HaiXiaLONG LaShengHUANG RongBinZHENG LanSun
Four 3d-4f heterometallic complexes, [CuⅡ-LnⅢ(bpt)2(NO3)3(MeOH)] (Ln = Gd, 1; Dy, 2; bptH = 3,5-bis(pyrid-2-yl)-l,2,4- triazole), [CuⅡ-LnⅢ(μ-OH)2(bpt)4C14 (H2O)2]·6H2O (Ln = Gd, 3; Dy, 4), have been synthesized under solvothermal condi- tions. X-ray structural analyses reveal that 1 and 2 are isostructural while 3 and 4 are isostructural. In each complex, the copper and gadolinium or dysprosium ions are linked by two triazolate bridges and form a CuⅡ-LnⅢ dinuclear unit. The intramolecu- lar Cu-Ln distances are 4.542, 4.525, 4.545 and 4.538 ] for 1, 2, 3 and 4, respectively. Two dinuclear CuLn units are bridged by two OH- groups into the zig-zag tetranuclear {cunzLnm2} structures with the Ln(Ⅲ)...Ln(Ⅲ) distances of 3.742 and 3.684 for 3 and 4, respectively. Magnetic studies show that the antiferromagnetic CulI-Lnm interactions occur in 1 (Jcu = -0,21 cm-1) and 2. The antiferromagnetic interaction occurs in complex 3 with JcuGa = -0.82 cm-1 and JcdGd = --0.065 cm-1, while domi- nant ferromagnetic interaction occurs in complex 4.
Synthesis and anionic polymerization of the fluorine-substituted phenyl methacrylates are herein reported. A series of monodi-, and multi-substituted fluorophenyl methacrylates H2C=C（CH3）C（O）OC6H4F-4 （M^1a）, H2C=C（CH3）C（O）OC6H4F-3 （M^1b）, HEC=C（CH3）C（O）OC6H3F2-2,4 （M^2）, H2C=C（CH3）C（O）OC6H2F3-2,3,4 （M^3）, H2C=C（CH3）C（O）OC6HF4-2,3,5,6 （M^4）, and H2C=C（CH3）C（O）OC6F5 （M^5） were synthesized and characterized. Initially, the polymerization was carded out on the monomer M^1a by using nBuLi, tBuLi, and KH as the respective catalysts; this approach produced the polymers in yields of 12%-50%, but with lower molecular weights. Similar results were obtained by using tBuLi for catalytically polymerizing the other five monomers. By introducing a co-catalyst MeAl（BHT）2, the catalysts Nail, LiH, and tBuOLi each were tested to polymerize M^1a, which gave the polymers in very low yields （3%-7%）. Polymer yields of 13%-27% were obtained by each of the catalysts LiAlH4, nBuLi, PhLi, and tBuLi in connection with MeAI（BHT）2, but a better yield （61%） was achieved with KH/MeAl（BHT）2. The KH/MeAl（BHT）2 catalyst system was further employed to polymerize M^1b and M^2, which afforded respective polymer yields of 12%-63% and 10%-53%, depending on the molar ratios of KH：MeAl（BHT）2 as well as on the monomer concentrations. All of the polymers produced were syndiotactically rich in structure, as indicated by either ^1H or ^19F NMR data. The polymerization mechanism by the combined catalyst system is proposed.
