The reaction of lanthanum(Ⅲ) nitrate and 5-nitroisophthalic acid in isopropanol/H2O under hydrothermal conditions leads to a 3D lanthanum-containing coordination polymer with the general chemical formula {[La6(Nip)9(H2O)4 ]·(H2O)4 }∞(1,Nip=5-nitroisophthalate).The single-crystal X-ray analyses show that this compound crystallizes in the orthorhombic system,space group Ima2 with a=9.7769(12),b=28.239(3),c=21.149(2),V=5839.1(11)3,Z=2,Mr=2859.61,Dc =1.626 g/cm 3,F(000)=2752.14040 reflections are collected,of which 5275 are unique (R int=0.0241).Final GOOF=1.083,R=0.0406 and wR=0.1182,R indices based on 5183 reflections with I〉2σ(I)(refinement on F2),443 parameters,1 restraint.Lp and absorption corrections were applied,=2.242mm-1.Absolute structure parameter x=0.08(3).The crystal structure can be described as the butterfly-liked hexanuclear lanthanum entities {La6O6(CO2)8 } covalently linked to each other by nitroisophthalate ligands into an intricate three-dimensional structure.The fluorescence spectroscopy of compound 1 has been investigated.
The polyoxometalate-imidazole ionic liquids(POM-ILs) with low melting points at 94.5 and 95.5 ℃, [Cn mim]a[MosO26](Cn mim=1-alkyl-3-methylimidazolium, n=12,14), have been successfully synthesized and characterized by DSC, single-crystal X-ray diffraction and TGA, etc. The two POM-ILs have relatively high stability with decomposing temperature up to about 347 and 344 ℃, respectively. Further photocatalytic performance was measured via the degradation of rhodamine B(RB) in aqueous solution. The experiments show that the conversion reached to 90% after 90 min under UV-light and the degradation efficiency depended on pH value, different dosages and so on. In addition, the catalysts can be recycled for several times without significant loss of activity.
The green synthesis of chloropropylene carbonate via the coupling reaction of carbon dioxide and epichlorohydrin had been achieved using halogen-free and single-component catalysts tetrabutylammonium salts of tritransition-metal-substituted A-α- tungstogermanate [(n-C4H9)4N]3H7GeW9M3(H2O)30O7 (M = Cu^Ⅱ, Ni^Ⅱ, Co^Ⅱ and Mn^Ⅱ) without any solvent. The catalytic activity was significantly depended on the transition metal introduced in polyoxometalates. [(n-C4H9)4N]3H7GeW9Mn3(H2O)3O37 exhibited the highest catalytic activity with 94.9% conversion for epichlorohydrin and 98% selectivity for chloropropylene carbonate in 3 h. Plausible mechanism was proposed based on the results.
Fa Wang ChenTao DongXiao Fang LiTie Gang XuChang Wen Hu