A novel flower-like hydrated magnesium carbonate hydroxide, Mg5 (CO3 )4 (OH)2·4H2O, with micro-structure composed of individual thin nano-sheets was synthesized using a facile solution route without the use of template or organic surfactant. Reaction time has an important effect on the final morphology of the product. The micro-structure and morphology of Mg5 (CO3)4 (OH)2·4H2O were characterized by means of X-ray diffractometry (XRD), fieldemission scanning electron microscopy(FE-SEM). Brunauer-Emmett-Teller(BET) surface areas of the samples were also measured. The probable formation mechanism of flower-like micro-structure was discussed. It was found that Mg5 (CO3)4( OH)2·4H2O with flower-like micro-structure was a novel and efficient catalyst for the synthesis of diphenyl carbonate (DPC) by transesterification of dimethyl carbonate (DMC) with phenol.
WANG QiangWANG Ke-liWU Xing-longLUO Sheng-junHU Chang-wen
A new three-dimensional supramolecule composed of copper-Schiff base complex, [Cu(naphdien)]Cl·H2O, where naphdien is Schiff base of 2-hydroxy-1-naphthaldehyde and diethylenetriamine, has been synthesized and determined by single-crystal X-ray diffraction. It belongs to the monoclinic system, space group P21/c, with a = 7.3490(15), b = 7.0847(16), c = 30.845(3)A, β= 95.33(3)°, V = 1599.0(5)A3, Z = 4, C15 H20ClCuN3O2, Mr = 373.33, De = 1.551 g/cm3, μ = 1.543 mm^-1, F(000) = 772, R = 0.0536 and wR = 0.0927 for 2788 unique reflections with 1659 observed ones (I 〉2σ(I)). In the crystal structure, mononuclear units [Cu(naphdien)]Cl·H2O are linked into a two-dimensional framework via strong hydrogen bonds, and extended into a three-dimensional supramolecular structure through π-π stacking interactions.
6-(3,5-Dimethylpyrazol-1-yl)-3-(2,4,6-trinitroanilino)-1,2,4,5-tetrazin (1) has been synthesized and characterized by ^1H NMR, MS, elemental analysis, infrared spectra and thermal analyses. The crystal structure was determined by X-ray diffraction method. 1 is crystallized in P21/c space group of monoclinic crystal system, and exhibits good physical properties, such as high densities (〉 1.55 g·cm^-3) and good thermal stabilities (Td〉220 ℃). The intrermolecular hydrogen bonds construct the P- and M-helices from organic molecules and may contribute to the high melting points.
A new 1D infinite neutral chain (Ph3SnO2SeOCH2CH3)n (1) based on organotin and selenious acid monoethyl ester has been synthesized successfully and characterized by IR, elemental analysis, and X-ray single-crystal diffraction. In the compound 1, the Sn atom exists in slightly distorted trigonal bipyramidal geometry and the Se center is tri-coordinated with a distorted pyramidal arrangement. It is noted that the synthesis is facile and selenium oxide is directly introduced into synthesis route replacing organoseleninic acid under room temperature.