Single‐Crystal‐to‐Single‐Crystal Transformation and Alcohols Enantioseparation of Homochiral Ir(III)‐Metallohelix‐Based Porous Molecular Crystal

• Published in: European journal of inorganic chemistry 2022-09, Vol.2022 (27), p.n/a
• Main Authors: Wu, Jinguo, Li, Xuezhao, Shi, Zhuolin, He, Cheng
• Format: Article
• Language: English
• Subjects: Alcohols; Alcohols enantioseparation; Carbon dioxide; Crystal transformation; Crystallization; Diethyl ether; Enantiomers; Helicate; Inorganic chemistry; Polymorphs; Porous molecular crystal; Selectivity; Transformations
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.202200351

Single‐crystal‐to‐single‐crystal (SCSC) transformations of porous crystals have been proved as an important platform for creating new materials. The current study describes porous molecular crystal with two different polymorphs based on the same chiral helicate modules can be controllably obtained when simply changing the crystallization solvents from diethyl ether to isopropyl ether. Interestingly, the β‐polymorph can also be effective obtained through SCSC transformations from α‐polymorph in solid state using isopropanol as a trigger. Compared with our reported α‐polymorph, the newly obtained β‐polymorph porous molecular crystal displays higher CO2 uptake and better selectivity for CO2 over N2 at 298 K. Meanwhile, as chiral solid adsorbents, both of β‐polymorph and α‐polymorph exhibit similar enantioselective separation abilities towards alcohols but different adsorption kinetics. The design and synthesis of new type of porous molecular crystal materials through solvent triggered SCSC transformation or dissolution‐recrystallization process is reported. The α‐Δ2R6‐H and β‐Δ2R6‐H with different polymorphs based on the same chiral helicate modules (Δ2R6‐H) presented different CO2 uptake capacity, CO2/N2 selectivity, and similar enantioselectivity toward alcohols with different adsorption kinetics.