Enhanced and Heteromolecular Guest Encapsulation in Nonporous Crystals of a Perfluorinated Triketonato Dinuclear Copper Complex

Yoshinori Ikumura, Yusuke Habuka, Shunichiro Sakai, Takanori Shinohara, Hidetaka Yuge, Izabela I. Rzeznicka, Akiko Hori

Research output: Contribution to journalArticle


The flexible host framework of a perfluorinated mononuclear copper complex, [Cu(L1)2] (1, HL1=3-hydroxy-1,3-bis(pentafluorophenyl)-2-propen-1-one), with a CuO4 core reversibly encapsulated several organic guest molecules through electrostatic interactions in its crystals. Hence, the corresponding dinuclear complex, [Cu2(L2)2] (2, H2L2=1,5-dihydroxy-1,5-bis(pentafluorophenyl)-1,4-pentadien-3-one), was prepared to enhance guest recognition and the ability to separate molecular mixtures. Complex 2 comprises a Cu2O6 core and four pentafluorophenyl groups. In crystal 2, cavities are formed on the axial sites of the metal core that are surrounded by pentafluorophenyl groups. The crystal of 2 encapsulates various guest molecules, that is, benzene (3), toluene (4), xylene (5), mesitylene (6), durene (7), and anisole (8). X-ray crystallographic and thermogravimetric (TG) studies show that three guest molecules are present in the crystal cavities. The number of guest molecules found in complex 2 was higher than that in complex 1, for example, (2)3⋅(6)10>1⋅(6)2, (2)2⋅(7)7>1⋅7, or 2⋅(8)3>1⋅(8)2. Naphthalene (9), was encapsulated in 2 to give 2⋅(9)3, but not in 1. In the crystal of complex 2, heteromolecular guest encapsulation was confirmed, designated as 2⋅(3)2⋅9. TG analysis indicates that the thermal stability of the guest-included crystals of 2 is higher than that of 1.

Original languageEnglish
Pages (from-to)5051-5060
Number of pages10
JournalChemistry - A European Journal
Issue number22
Publication statusPublished - 2020 Apr 16



  • copper
  • crystal growth
  • dinuclear compounds
  • fluorinated substituents
  • host–guest systems
  • supramolecular chemistry

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

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