Reversible Transformation between Cubane and Stairstep Cu4I4 Clusters Using Heat or Solvent Vapor

• Published in: Chemistry : a European journal Vol. 21; no. 4; pp. 1439 - 1443
• Main Authors: Cho, Seonghwa, Jeon, Youngeun, Lee, Sangjin, Kim, Jineun, Kim, Tae Ho
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 19.01.2015; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Chemistry; cluster transformation; coordination polymers; crystal transformation; photoluminescence; supramolecular chemistry; coordination polymers; cluster transformation; crystal transformation; photoluminescence; supramolecular chemistry
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201405800

The controlled self‐assembly of CuI and an asymmetric ligand with mixed N/S donors, 2‐(tert‐butylthio)‐N‐(pyridin‐3‐yl)acetamide (L), afforded three CuI coordination polymers (CPs), [Cu4I4L2(MeCN)2]n (1), [Cu4I4L2]n (2), and {[Cu4I4L2]⋅MeOH}n (3). X‐ray analyses showed that CPs 1–3 are supramolecular isomers with 1, 2, and 3D structures, respectively. CP 1 adopts a stairstep Cu4I4 cluster, whereas CPs 2 and 3 are composed of cubane‐like Cu4I4 clusters. Crystal‐to‐crystal transformations of 1 to 2 and 3 showed reversible transformations between different Cu4I4 clusters using heat or solvent (acetonitrile or methanol) vapor. CP 2 was reversibly transformed to 3 by the addition of methanol and heat. Therefore, the transformations between supramolecular isomers 1, 2, and 3 are completely reversible. Cluster transformations: Three supramolecular isomeric CuI coordination polymers showed reversible crystal transformations using solvent vapor or the application of heat (see scheme). Surprisingly, transformations between stairstep and cubane Cu4I4 clusters were observed during the crystal transformations.