Synthese, Kristallstruktur und Festkörper‐NMR‐spektroskopische Untersuchung des Oxonitridosilicates BaSi6N8O
Synthese, Kristallstruktur und Festkörper‐NMR‐spektroskopische Untersuchung des Oxonitridosilicates BaSi6N8O
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DOI：
10.1002/zaac.200500180
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发表时间：
2005-08
期刊：
影响因子：
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通讯作者：
F. Stadler;Robert Kraut;Oliver Oeckler;S. Schmid;W. Schnick
中科院分区：
文献类型：
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作者：
F. Stadler;Robert Kraut;Oliver Oeckler;S. Schmid;W. Schnick
氧氮硅酸盐BaSi 6 N8 O的合成、晶体结构和固体核磁共振谱研究以BaCO 3和硅二酰亚胺Si（NH）2为原料，在射频炉中，在低于1630 °C的温度下，合成了纯相的氧氮硅酸盐BaSi 6 N8 O，它是一种无色的粗晶材料。其结构经X射线单晶衍射分析确定（BaSi_6 N_8 O，空间群I_m ~ 2（no.44），a = 810.5（2），B = 967.8（2），c = 483.7（1）pm，V = 379.4（2）·106 pm ~ 3，Z = 2，R_1 = 0.014，618个独立反射，44个参数）。氧氮硅酸盐包括角共享SiN 4和SiON 3四面体的三维网络结构，其中Ba 2+位于所得空隙中。BaSi 6 N8 O与氧氮铝硅酸盐（sialon）Sr 2AlxSi 12 − xN 16 − xO 2 +x（x <$2）是同构的，这在以前的文献中已经描述过。此外，BaSi_6N_8O的阴离子网络通过氧拓扑插入到Si-Si单键中而衍生自同型还原的氮硅酸盐SrSi_6N_8的阴离子网络。在29 Si MAS-NMR谱中，分别在−54.0和−56.3 ppm处观察到两个尖锐的各向同性信号。关于它们观察到的强度比1：2.1（1），这两个信号必须分别归因于SiON 3和SiN 4四面体的中心原子，这与X射线晶体结构测定（Si在维科夫位置4d（SiON 3）和8 e（SiN 4））一致。
Synthesis, Crystal Structure and Solid-State NMR Spectroscopic Investigation of the Oxonitridosilicate BaSi6N8O The phase-pure oxonitridosilicate BaSi6N8O has been synthesized starting from BaCO3 and silicon diimide Si(NH)2 in a radiofrequency furnace at temperatures below 1630 °C as a coarsely crystalline colorless material. The structure has been determined by single-crystal X-ray diffraction analysis (BaSi6N8O, space group Imm2 (no. 44), a = 810.5(2), b = 967.8(2), c = 483.7(1) pm, V = 379.4(2)·106 pm3, Z = 2, R1 = 0.014, 618 independent reflections, 44 parameters). The oxonitridosilicate comprises a three-dimensional network structure of corner sharing SiN4 and SiON3 tetrahedra with Ba2+ located in the resulting voids. BaSi6N8O is isostructural with the oxonitridoalumosilicate (sialon) Sr2AlxSi12−xN16−xO2+x (x ≈ 2) that previously has been described in the literature. Furthermore, the anionic network of BaSi6N8O derives from that of the homeotypic reduced nitridosilicate SrSi6N8 by a topotactic insertion of oxygen into the Si–Si single bonds. In the 29Si MAS-NMR spectrum two sharp isotropic signals have been observed at −54.0 and −56.3 ppm, respectively. With respect to their observed intensity ratio of 1 : 2.1(1) these two signals have to be attributed to the central atoms of SiON3 and SiN4 tetrahedra, respectively, which is in accordance with the X-ray crystal structure determination (Si at Wyckoff positions 4d (SiON3) and 8e (SiN4)).