Metastability and Seeding Effects in the Mechanochemical Hybrid Lead(II) Iodide Formation. Issue 19 (3rd March 2021)

• Record Type: Journal Article
• Authors: Wilke, Manuel; Gawryluk, Dariusz Jakub; Casati, Nicola
• Is Part Of: Chemistry. Volume 27:Issue 19(2021)
• Page Start: 5944
• Page End: 5955
• Publication Date: 2021-03-03
• Subjects: hybrid composites -- mechanochemistry -- solid-state reactions -- X-ray diffraction; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202004431
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The mechanism for the mechanochemical synthesis of (C(NH2 )3 )3 PbI5 3 and (C(NH2 )3 )4 PbI6 4 and their conversion into each other is presented. We investigated the synthesis of 3 at different frequencies and energies using in situ powder X‐ray diffraction. By splitting the reaction into single parts we could prove that the formation of 3 is simply dependent on the energy and mixing speed. The nucleation of 4 instead is slightly negative dependent on the energy but dependent on the mixing speed, while its growth is mostly independent of any influence. We were able to influence the reaction pathways by seeding the mixture with a small amount of powdery 4 . The formation of 4 is very likely an auto‐catalytic process. 3 instead is metastable. It can be stabilized by energy, which beside mechanochemistry can also be achieved by temperature. The results showcases the complex nature of mechanochemical reactions. Abstract : Comprehensive in situ investigations allow for the formulation of a mechanism for the mechanochemical formation of two hybrid lead iodides. Via mechanochemistry or temperature the metastable compound can be stabilized. Its formation is strongly correlated with the formation of the second compound, which can be influenced by seeding.