Ammonothermal Synthesis of Alkali‐Alkaline Earth Metal and Alkali‐Rare Earth Metal Carbodiimides: K 5– x M x (CN 2 ) 2 +x (HCN 2 ) 1– x ( M = Sr, Eu) and Na 4.32 Sr 0.68 (CN 2 ) 2.68 (HCN 2 ) 0.32

Autor:	Wolfgang Schnick, Mathias Mallmann, Niklas Cordes, Jonas Häusler
Rok vydání:	2017
Předmět:	Alkaline earth metal 010405 organic chemistry Potassium Inorganic chemistry chemistry.chemical_element Crystal structure 010402 general chemistry Alkali metal 01 natural sciences 0104 chemical sciences Inorganic Chemistry Metal Crystallography chemistry.chemical_compound chemistry visual_art visual_art.visual_art_medium Potassium azide Earth (classical element) Carbodiimide
Zdroj:	Zeitschrift für anorganische und allgemeine Chemie. 643:1956-1961
ISSN:	1521-3749 0044-2313
Popis:	Alkali-alkaline earth metal and alkali-rare earth metal carbodiimides, namely K5-xMx(CN2)(2+x)(HCN2)(1-x) (x = 0 - 1) (M = Sr, Eu) and Na4.32Sr0.68(CN2)(2.68)(HCN2)(0.32), were synthesized under ammonothermal conditions in high-pressure autoclaves. The structures of the three compounds can be derived from homeotypic K5H(CN2)(3) and Na5H(CN2)(3) by partial substitution of K+ or Na(+)by Sr2+ or Eu2+. The reactions were carried out in two step syntheses (T-1 = 673 K, T-2 = 823 K) starting from sodium or potassium azide, dicyandiamide and strontium or Eu(NH2)(2), respectively. The crystal structures were solved and refined from single-crystal X-ray diffraction data K4.16Sr0.84(CN2)(2.84)(HCN2)(0.16): space group Im (3) over barm (no. 229), a = 7.8304(5) angstrom, Z = 2, R-1 = 0.024, wR(2) = 0.052;K4.40Eu0.60(CN2)(2.60)(HCN2)(0.40): space group Im (3) over barm (no. 229), a = 7.8502(6) angstrom, Z = 2, R-1 = 0.022, wR(2) = 0.049]. In contrast to the potassium carbodiimides, the sodium-strontium carbodiimide was only synthesized as microcrystalline powder. The crystal structure was determined by powder X-ray diffraction and refined by the Rietveld method [Na4.32Sr0.68(CN2)(2.68)(HCN2)(0.32): space group Im (3) over barm (no. 229), a = 7.2412(1) angstrom, Z = 2, R-wp = 0.050]. The presence of hydrogencyanamide units ([HNCN](-)) next to carbodiimide units ([CN2](2-)) in all compounds was confirmed by FT-IR spectroscopy.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::f5ddc0a05a95402d1e10481c96475e03 https://doi.org/10.1002/zaac.201700238 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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