Reaction pathways for the formation of thiolate-gold nanoparticles are investigated by density functional theory （DFT） and a new mechanism upon solvent polarity and tetraalkylammonium is obtained. In solvents with high polarities, [Au（I）SR]n polymers can be formed as the precursor of metal ions prior to the addition of a reducing agent; while a product of [Cl...AuCl（HSR）] is identified as the precursor in solvents with low polarities, such as toluene and chloroform. In addition, tetraalkylammonium also has an obvious effect on the reactions when it is used as a phase transfer agent in the two-phase synthesis. These findings offer a systematic analysis on the pathways to thiolate-stabilized nanoparticles and give a favorable explanation by comparison with those in an experimental system.
Hierarchical flower-like architectures of[Ni_3（BTC）_2·12H_2O]（BTC^3=benzene-1,3,5-tricarboxylate） were successfully prepared by a simple solution-phase method under mild conditions without any template or surfactant.Phase-pure porous NiO nanocrystals were obtained by annealing the Ni-BTC complex without significant alteration in morphology.The product was characterized by X-ray diffraction techniques,field-emission scanning electron microscopy（FESEM）.transmission electron microscopy（TEM） and high-resolution TEM（HRTEM）.The catalytic effect of the NiO product was investigated on the thermal decomposition of ammonium perchlorate（AP） and it was found that the annealed NiO product has higher catalytic activity than the commercial NiO.
Three novel coordination polymers, [Ni2(tib)2(btec)]·2H2O (1), [Co2(tib)2(btec)]·2H2O (2) and [Zn4(tib)2(btec)Cl4]·2H2O (3), have been synthesized by using mixed ligands of 1,3,5-tris(1-imidazolyl)benzene (tib) and 1,2,4,5-benzenetetracarboxylic acid (H4btec) under hydrothermal conditions. Complexes 1 and 2 have the same structure and are rare three-dimensional (3D) self-penetrating (3,4,5)-connected nets, while complex 3 is an unprecedented (3,4)-connected 3D net. The different structures of 1 (2) and 3 are ascribed to the distinct coordination geometry of the metal centers. The thermal stability and photoluminescence property of the complexes were investigated.
SU Zhi, FAN Jian & SUN WeiYin State Key Laboratory of Coordination Chemistry
Two novel compounds {[Cu（IBG）（4,4-bipy）（H2O）2]2·11H2O}n（1） and {[Co（IBG）-（μ-H2O）（H2O）2]·2H2O}n（2） based on isophthaloylbisglycine（H2IBG） have been synthesized and structurally characterized by thermogravimetric analysis, elemental analysis and single-crystal X-ray diffraction. Compound 1 shows a 1D chain sine/cosine chain structure, and compound 2 can be characterized as a 4-connected sql tetragonal planar network with the point symbol of {44·62}. Compound 2 has been characterized by magnetic measurements. In addition, 1 and 2 display an interesting reversible crystal-to-amorphous transformation.
