Cocrystals for photochemical solid-state reactions: An account on crystal engineering perspective

• Published in: Coordination chemistry reviews Vol. 483; p. 215095
• Main Authors: Akhtaruzzaman, Khan, Samim, Dutta, Basudeb, Kannan, Tamil Selvan, Kumar Kole, Goutam, Hedayetullah Mir, Mohammad
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.05.2023
• Subjects: Cocrystal; Crystal engineering; Cyclobutane; Hydrogen bonding; Photodimerization; Solid-state; Photodimerization; Crystal engineering; Solid-state; Cyclobutane; Hydrogen bonding; Cocrystal
• ISSN: 0010-8545; 1873-3840
• DOI: 10.1016/j.ccr.2023.215095

This review article describes recent development of intriguing cocrystals for the template controlled synthesis of functional cyclobutane compounds on crystal engineering perspectives. [Display omitted] •The use of cocrystals in photochemical [2 + 2] cycloaddition reactions is summarized.•Developments on the use of cocrystals for photochemical reactions are incorporated.•Potential future directions and opportunities using existing materials are discussed.•Reactions with possible new next generation materials are outlined. Syntheses of functional cyclobutanes, i.e., strained four-membered ring compounds are mainly achieved via photochemical [2 + 2] cycloaddition reaction. The key is to bring two reacting olefins (C=C bonds) in close proximity. Conducting such reactions in the solution-phase leads to the formation of a mixture of products, including trans–cis isomerization of the olefin monomer. On the other hand, in the solid-state, a particular product is obtained exclusively. However, the challenges remain to bring a pair of reacting olefin molecules in parallel stacking in its crystalline state, within the range of appropriate distance (Schimdt criteria). In crystal engineering, by exploiting weak intermolecular interactions, a wide variety of crystalline solids, including cocrystals, organic salts, host–guest adduct, coordination complexes and polymers have been designed for synthesizing cyclobutane compounds exclusively in the solid-state. In this review article, we emphasize the importance of cocrystals, underlying crystal engineering principles, and the recent developments on fascinating cocrystals for template-controlled synthesis of functional cyclobutane compounds. Utility of such compounds as ligands in the construction of network solids (cocrystals and coordination polymers) has also been addressed. However, we have restricted our discussion only on the neutral cocrystals, and hence organic salts or ionic cocrystals are not included in this article.