Exploration of expanded porphyrins with unprecedented reactivities has remained important. Here [22]pentaphyrins(2.0.1.1.0) were synthesized as a constitutional isomer of sapphyrin by acid-catalyzed cyclization of 1,14-dibromo-5,10-diaryltripyrrin with 1,2-di(pyrro-2-ly)ethenes. These pentaphyrins display roughly planar structures and varying aromaticities depending upon the vinylene structures. The 19,20-ditolyl pentaphyrin gave an N-fused product and an unprecedented pyrrole-rearranged product, depending upon the oxidation conditions. Remarkably, upon the metalation with CuCl, the N-fused product and the pyrrole-rearranged product afforded an inner β-β coupled face-to-face Cu
Transmetalation of 1,4-dilithio-1,3-butadienes with Ba[N(SiMe3)2]2 gave barium dibenzopentalenides, which were structurally characterized by single-crystal X-ray analysis. A preliminary study of the reaction chemistry of thus obtained barium dibenzopentalenides demonstrated that synthetically useful applications can be expected.
The oxidation resistance is one of the most important properties of refractory materials.China national standard GB/T 32329-2015, which title is "Test method for oxidation resistance of oxynitride materials-non-isothermal oxidation", provide a standard characterizing method for oxidation resistance.In our work we validate this standard and test the oxidation resistance of six SiAlON samples using this method.The oxidation resistance property of oxynitride materials could be well described with these indicators: the oxidation weight gain per unit area, the initial oxidation temperatures and the maximum oxidation rate temperatures.From the experimental results we conclude that this standard is scientific and feasible.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
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