＜正＞In constructing MOFs,as new functional solids,polycarboxylates is a good candidate for synthesizing compoun...
Li-Jun Zhou~1 Yao-Yu Wang~2 (1 Department of Applied Chemistry,XidianUniversity,Xi''an,710071, 2 Department of Chemistry/Shaanxi Key Laboratory of Physico-inorganic Chemistry,Northwest University,Xi''an 710069)
{[Cu^Ⅱ（Hpb）（mal）]H=O}n （Hpb=2-2＇-pyridylbenzimidazole, mal=maleic acid） is a helical chain-like polymer complex. In order to investigate the electronic structure of the complex, the monomer Cu^Ⅱ（Hpb）（mal） was obturated with different functional groups respectively. For these selective segments, the geometry optimizations were conducted by using hybrid DFT （B3LYP）methods to find that the structure obturated with H2O was better consistent with the experiment, and then this model would be used to latter calculations, such as the frontier molecular orbital and the NBO charge population analysis. In addition the magnetic behaviors of this complex were analyzed by experiments and the weak antiferromagnetic couple between copper（Ⅱ） ions was observed. The exchange coupling constant was calculated by DFT based on the spin broken symmetry formalism. The calculated coupling constants were in good agreement with the experimental data.
Two novel supramolecular complexes [Cu（bpapa）（dhbd）]·CHaOH （1） and [Cu（bpapa）（ma）]·ma （2） （bpapa= bis[6-（2-pyridylamino）pyrid-2-yl]amine, dhbd=2,3-dihydroxybutanedioate dianion, ma=a-methacrylate） were rationally designed, synthesized and characterized by single crystal X-ray diffraction, IR, electronic spectroscopy and thermogravimetric analyses. Complex 1 was the first oligo-a-pyfidylamino complex based on hydroxypolycarboxylate and self-assembled into a 3D honeycomb configuration network with open channels and tubes containing 1D ladder-shaped double chains formed by hydrogen bonds and aromatic π-π stacking interactions. Complex 2 constructed a 2D supramolecular network extended by 1D chains from dimeric supramolecular synthon through noncovalent supramolecular interactions. In the two complexes, the chelating monohelical ligand adopted all-anti configuration. Density functional theory calculations were applied to 1 and 2.
α-Fe2O3 nanoparticles were successfully prepared by a sonochemical method in FeCl3-NH3 complex solution.The obtained sample was examined and investigated by XRD,TEM,FT-IR,FT-Raman and XPS techniques.The results showed that the spherical,well-dispersed α-Fe2O3 nanoparticles were obtained with the average size of 15nm.The possible formation mechanism of α-Fe2O3 nanoparticles were also discussed,which indicated that this for the preparation of the nanoparticles method can be used for α-Fe2O3 preparation with some practical and universal significance.
A series of ultrafine amorphous NiCoB alloys was prepared by chemical reduction method.XRD,TEM and BET techniques were used to investigate the phase,morphology,particle size and activity of the catalyst for the hydrogenation of soybean oil.The results indicated that their activities are higher than that of Raney Ni,Moreover,with the increasing of Ni/Co molar ration,the catalytic activity of the catalysts versus Ni/Co ration passe through a maximum at Ni/Co=0.5,at which the grain size and specific surface area were 20nm and 46.9m2·g-1,respectively.As an high effective environmental amicable catalyst,ultrafine amorphous NiCoB alloys can be used to the hydrogenation of soybean oil.
Using the V-shaped oba dianions as bridging ligands and dpa molecules as terminal ligands, a new 1D helical coordination-polymeric chain, [Zn（oba）（dpa）]n [oba=oxybis（4-benzoate）, dpa=di（2-pyridyl）amine], was synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, UV-Vis and IR spectra, and TGA analysis. X-ray structural analysis revealed that, oba and dpa ligands played an important role in the self-assembly of the helical chains by providing potential supramolecular recognition sites for π-π aromatic stacking and hydrogen-bond interactions, resulting in the self-assembly of the （4,4） networks to give a 3-D supramolecular framework. The photoluminescence properties of the title compound were also investigated, showing intense blue photoluminescence properties at room temperature.
Two novel supramolecular complexes, [Cu（bopapa）（mal）]·H2O·CH3OH （1） and {[Cu（bopapap）]（Hmal）2}·2H2O （2） [bpapa = bis-[6-（2-pyridylamino）pyrid-2-yl]amine, bpapap = 2,6-bis-[6-（pyrid-2-ylamino）pyrid-2-ylamino]- pyridine, mal=maleate dianion] were rationally designed and synthesized based on flexible multidentate ligands and copper（Ⅱ） maleate. Complexes 1 and 2 were all characterized by elemental analysis, spectroscopic techniques, thermal analysis and single crystal X-ray diffraction analysis. Complex 1 is of an infinite 3-D supramolecular framework constructed by 2-D sheets to contain 1-D helical chains formed by intermolecular hydrogen bond inter- actions between the non-coordinated oxygen atoms from maleate and nitrogen atoms from amino groups of bpapa. Complex 2 also takes a 3-D supramolecular structure, which is built from 2-D rhombic sheets produced by sequential dimer units. Interestingly, three pairs of symmetrical hydrogen bonds generate these dimer units.
