کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
72251 49014 2016 17 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Four organo-templated structures with DFT-zeotype topology: Variation in symmetry of similar microporous structures
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Four organo-templated structures with DFT-zeotype topology: Variation in symmetry of similar microporous structures
چکیده انگلیسی


• For new compounds were grown hydrothermally.
• They exhibit DFT-zeotype structures.
• Analysis of symmetry relationships of DFT-zeotype compounds was undertaken.
• Structure distortion using the program COMPSTRU was analyzed.

Four novel microporous compounds H2(C2H8N2)(ZnAsO4)2 (1), H2(C2H8N2)(Co0.1Zn0.9AsO4)2 (2), H1.8(C2H8N2)(Fe0.1Zn0.9AsO4)2 (3) and H2(C2H8N2)(ZnPO4)2 (4) containing ethylenediammonium cation, H2(C2H8N2)2+ (H2en2+), and ethylenediamine molecule, C2H8N2 (en), have been hydrothermally synthesized. While 1–3 exhibit twinned DFT-zeotype structure and crystallize in P42/n, 4 is characterized by the appearance of new orthorhombic space group Pcca, previously not observed among the known DFT-zeotype compounds. The symmetry relationships analyses revealed the extended Bärnighausen tree. The main feature of the cobalt blue and reddish brown compounds 2 and 3 is their novel chemical composition which was confirmed by SEM/EDX analysis. In the structure of 1, H-atoms positions, previously not reported, were calculated and refined to reasonable positions using riding model.The DFT anionic frameworks of 1–4 are characterized by 4M, 6M and 8M tetrahedral rings, which produce three mutually perpendicular 8M ring channels. At the intersections of these channels H2en2+ cations are accommodated and hydrogen-bonded to the adjacent oxygen atoms of the framework. Only in 3, H2en2+ is partly substituted by electroneutral en to maintain charge compensation. The single-crystal Raman spectra and Fourier transform infrared (FTIR) absorption spectra were interpreted on the basis of characteristic vibrations of AsO4 and PO4 groups, as well as of NH3, NH2 and CH2 groups from the H2en2+ cation or en molecule.The results of lattice distortion and similarity analyses showed that the DFT-zeotype structures, which incorporate larger tetrahedral cations, have a higher degree of lattice distortion and are less similar to the ideal structural models derived from the aristotype.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Microporous and Mesoporous Materials - Volume 220, 15 January 2016, Pages 198–214
نویسندگان
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