Many metal-organic cages (MOCs) and a few hydrogen-bonded organic cages (HOCs) have been investigated, but little is reported about cooperative self-assembly of MOCs and HOCs. Herein, we describe an unprecedented MOC&HOC co-crystal composed of tetrahedral Ti4L6 (L=embonate) cages and in-situ-generated [(NH3)(4)(TIPA)(4)] (TIPA=tris(4-(1H-1,2,4-triazol-1-yl)phenyl)amine) cages. Chiral transfer is observed from the enantiopure Ti4L6 cage to enantiopure [(NH3)(4)(TIPA)(4)] cage. Two homochiral supramolecular frameworks with opposite handedness (PTC-235(Delta) and PTC-235(Lambda)) are formed. Such MOC&HOC co-crystal features high stability in water and other solvents, affording single-crystal-to-single-crystal transformation to trap CH3CN molecules and identify disordered NH4+ cations. A tablet pressing method is developed to test the third-order nonlinear optical property of KBr-based PTC-235 thin film. Such a thin film exhibits an excellent optical limiting effect.

metal-organic cages; nonlinear optics; self-assembly; titanium

University of Chinese Academy of Sciences; Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences