Stepwise Stress‐Induced Transformations of Metal‐Organic Polyhedral Cluster‐Based Assemblies: Where Conformational and Supramolecular Features Meet

• Published in: Chemistry : a European journal Vol. 27; no. 55; pp. 13757 - 13764
• Main Authors: Terlecki, Michał, Sobczak, Szymon, Leszczyński, Michał K., Katrusiak, Andrzej, Lewiński, Janusz
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.10.2021
• Subjects: Chemistry; Clusters; Conformation; Coordination; Crystal structure; Crystals; high-pressure chemistry; molecular crystals; Molecular structure; noncovalent interactions; Perturbation; Phase transitions; Pressure; zinc-oxo clusters
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202101732

Understanding the factors governing the formation of supramolecular structures and phase transitions between various forms of molecular crystals is pivotal for developing dynamic, stimuli‐responsive materials and polymorph‐controlled syntheses. Here, we investigate the pressure‐induced dynamic of both the intrinsic molecular structure and the supramolecular network of a predesigned polyhedral oxo‐centered zinc cluster incorporating monoanionic N,N’‐diphenylformamidinate and featuring N‐bonded phenyl groups in close proximity to the primary coordination sphere. We demonstrate that the model oxo cluster is prone to undergoing pressure‐induced conformational transformations of the secondary coordination sphere and simultaneous stepwise (initially every second polyhedral molecule undergoes the conformational transformations) and reversible transitions from an ambient phase α to high‐pressure phases β and γ, as single‐crystal‐to‐single‐crystal events. The observed phase transitions illustrate the key role of an interplay between the low‐energy conformation perturbations and cooperative intra‐ and intermolecular noncovalent interactions. Squeezed to change: We demonstrate that a predesigned polyhedral oxo‐centered metal complex with remote phenyl rings can undergo reversible pressure‐induced conformational transformations of the secondary coordination sphere and simultaneous stepwise (initially every second polyhedral molecule undergoes the conformational transformations) and reversible transitions from an ambient phase α to high‐pressure phases β and γ, as single‐crystal‐to‐single‐crystal events.