Solving the Hydrogen and Lithium Substructure of Poly(triazine imide)/LiCl Using NMR Crystallography

authored by: Maria B. Mesch, Kilian Bärwinkel, Yaşar Krysiak, Charlotte Martineau, Francis Taulelle, Reinhard B. Neder, Ute Kolb, Jürgen Senker
Abstract: 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 P2₁2₁2₁. In this way, we demonstrate that, in particular, the above-mentioned techniques allow for smart interplay in delineating the real structure of PTI/LiCl.
External Organisation(s): University of Bayreuth
Johannes Gutenberg University Mainz
Universite de Versailles
Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU Erlangen-Nürnberg)
Type: Article
Journal: Chemistry - a European journal
Volume: 22
Pages: 16878-16890
No. of pages: 13
ISSN: 0947-6539
Publication date: 08.11.2016
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Catalysis, Organic Chemistry
Sustainable Development Goals: SDG 7 - Affordable and Clean Energy
Electronic version(s): https://doi.org/10.1002/chem.201603726 (Access: Closed)