MS35-P06 Pressure-induced solid-state reactions of coordination polymersMetal-organic frameworks (MOF’s) and Coordination Polymers (CP’s) are classified as the interdisciplinary field between the coordination and inorganic chemistry. For decades, these porous materials have been thoroughly investigated because of their potential applications, such catalysis and sensing as well as the storage of fuel gases and water.1 Presently, high pressure has become an established highly-efficient tool for inducing strong structural transformations in various compounds.2 In particular high pressure can be applied for post-synthetic modification (PSM) of CP’s. Several approaches have been used for PSM, but the category of pressure induced modifications has merely begun to emerge.
Herein we present 2-dimensional cadmium coordination polymer Cd(APP)2NO3 ∙ NO3 [APP abbreviates 1,4-bis(3aminopropyl)piperazine], undergoing a pressure induced associative reaction to cis-Cd(APP)2(NO3)2. Our high-pressure structural measurements revealed that at 0.4 GPa a rearrangement of the Cd-coordination sphere takes place, which is connected with the formation of a new additional coordination bond. As a result of this reaction, a nitrate anion, detached of the cation and located in the crystal void space in the phase I, is transferred to the metal center. Consequently, the cadmium ligancy increases from 6 to 7 in phase II. The high-pressure reactivity of CP’s can be explained by three simple rules: involving the metal/ligand ionic radii ratio, the elimination of potential voids in the compressed structure as well as the vicinity from the metal center to reacting anions.References:
(1) Zhou, H. C., Long, J. R. & Yaghi, O. M. Introduction to metal-organic frameworks; Chem. Rev. 112, 673–674 (2012).
(2) Katrusiak, A.; McMillan, P. High-Pressure Crystallography; Springer Science & Business Media, 2004; Vol. 140. Keywords: Coordination Polymers; high pressure; new bond formation