Noncovalent interactions are essential in the formation and function of a diverse range of hybrid materials. However, reliably identifying the noncovalent interactions in nanocrystalline materials remains challenging using conventional methods such as X-ray diffraction and spectroscopy. Here, we demonstrate that the entire range of noncovalent interactions in a nanocrystalline aluminophosphate hybrid material SCM-34 can be directly visualized by accurately determining all atomic positions using 3D electron diffraction (3D ED). The resolved hydrogen atoms reveal the protonation states of the inorganic and organic components. All the noncovalent hydrogen bonding, electrostatic, π–π stacking, and Van der Waals interactions were unambiguously resolved, providing a detailed insight into the material formation mechanism. The data are sufficiently accurate to distinguish the different types of covalent bonds based on their bond lengths, and we observed an elongated terminal P=O π-bond caused by noncovalent interactions. Our results illustrate 3D ED can be a powerful tool for resolving detailed noncovalent interactions in nanocrystalline hybrid materials, improving our understanding of hybrid systems and guiding the development of novel functional materials.
The supporting Information includes the synthetic procedures, characterization methods and data (3D ED, XRD, SEM, TGA, NMR, etc.), and structure refinement details of SCM-34.
Crystal structure of SCM-34 determined by 3D electron diffraction.