Mesch Maria B, Bärwinkel Kilian, Krysiak Yaşar, Martineau Charlotte, Taulelle Francis, Neder Reinhard B, Kolb Ute, Senker Jürgen
Inorganic Chemistry III, University of Bayreuth, 95447, Bayreuth, Germany.
Institute of Inorganic Chemistry and Analytical Chemistry, Johannes Gutenberg University Mainz, Jakob-Welder-Weg 11, 55128, Mainz, Germany.
Chemistry. 2016 Nov 14;22(47):16878-16890. doi: 10.1002/chem.201603726. Epub 2016 Oct 13.
Poly(triazine imide) with incorporated lithium chloride has recently attracted substantial attention due to its photocatalytic activity for water splitting. However, an apparent H/Li disorder prevents the delineation of structure-property relationships, for example, with respect to band-gap tuning. Herein, we show that through a combination of one- and two-dimensional, multinuclear solid-state NMR spectroscopy, chemical modelling, automated electron diffraction tomography, and an analysis based on X-ray pair distribution functions, it is finally possible to resolve the H/Li substructure. In each cavity, one hydrogen atom is bound to a bridging nitrogen atom, while a second one protonates a triazine ring. The two lithium ions within each cavity are positioned between two nitrogen atoms of neighbouring triazine rings. The thereby induced local dipole moments cause slight buckling of the framework and lateral displacements of the Cl ions at a coherence length below 2 nm. Nevertheless, the average structure conforms to space group P2 2 2 . In this way, we demonstrate that, in particular, the above-mentioned techniques allow for smart interplay in delineating the real structure of PTI/LiCl.
最近，掺入氯化锂的聚（三嗪酰亚胺）因其在光催化水分解方面的活性而备受关注。然而，明显的氢/锂无序阻碍了结构-性能关系的描述，例如在带隙调谐方面。在此，我们表明，通过结合一维和二维多核固态核磁共振光谱、化学建模、自动电子衍射断层扫描以及基于X射线对分布函数的分析，最终有可能解析氢/锂子结构。在每个空腔中，一个氢原子与一个桥连氮原子相连，而另一个氢原子使一个三嗪环质子化。每个空腔内的两个锂离子位于相邻三嗪环的两个氮原子之间。由此产生的局部偶极矩导致框架轻微弯曲以及氯离子在低于2 nm的相干长度上发生横向位移。尽管如此，平均结构符合空间群P2 2 2 。通过这种方式，我们证明，特别是上述技术在描绘PTI/LiCl的真实结构时能够实现巧妙的相互作用。
