Guńka Piotr A, Kraszewski Karol, Chen Yu-Sheng, Zachara Janusz
Warsaw University of Technology, Faculty of Chemistry, Noakowskiego 3, 00-664 Warszawa, Poland.
Dalton Trans. 2014 Sep 7;43(33):12776-83. doi: 10.1039/c4dt01569j.
Unprecedented intercalates of arsenic(iii) oxide with potassium azide and ammonium azide have been obtained and characterized by single crystal X-ray diffraction. The compounds are built of As2O3 sheets separated by charged layers of cations and azide anions perpendicular to the sheets. The intercalates are an interesting example of hybrid materials whose structure is governed by covalent bonds in two directions and ionic bond in the third one. The obtained compounds are the first examples of As2O3 intercalates containing linear pseudohalogen anions. Periodic DFT calculations of interlayer interaction energies were carried out with the B3LYP-D* functional. The layers are held together mainly by ionic bonds, although the computations indicate that interactions between cations and As2O3 sheets also play a significant role. A comparison of cation and anion interaction energies with neutral As2O3 sheets sheds light on the crystallisation process, indicating the templating effect of potassium and ammonium cations. It consist in the formation of sandwich complexes of cations with crown-ether-resembling As6O12 rings. Raman spectra of both compounds are recorded and computed ab initio and all vibrational bands are assigned.
已获得前所未有的三氧化二砷与叠氮化钾和叠氮化铵的插层化合物，并通过单晶X射线衍射对其进行了表征。这些化合物由As₂O₃片层构成，片层之间由垂直于片层的阳离子和叠氮阴离子的带电层隔开。这些插层化合物是混合材料的一个有趣例子，其结构由两个方向的共价键和第三个方向的离子键决定。所获得的化合物是含线性拟卤阴离子的As₂O₃插层化合物的首个实例。使用B3LYP-D*泛函对层间相互作用能进行了周期性密度泛函理论计算。层间主要通过离子键结合在一起，不过计算表明阳离子与As₂O₃片层之间的相互作用也起着重要作用。将阳离子和阴离子与中性As₂O₃片层的相互作用能进行比较，有助于了解结晶过程，表明钾离子和铵离子阳离子的模板效应。这在于形成阳离子与类似冠醚的As₆O₁₂环的夹心配合物。记录并从头计算了两种化合物的拉曼光谱，并对所有振动带进行了归属。
