title: Ion-Pairing Crystal Polymorphs of Interlocked [2 + 1]-Type Receptor-Anion Complexes.
abstract: The formation of a solid-state totally charge-segregated assembly (polymorph A) of negatively charged layers comprising [2 + 1]-type Cl(-) complexes of an arylethynyl-substituted dipyrrolyldiketone boron complex and positively charged layers of tetrabutylammonium (TBA) cations has already been reported. The formation of two new crystalline polymorphs (polymorphs B and C), in addition to polymorph A, is reported in this study. Both polymorphs B and C formed charge-by-charge assemblies, and the dihedral angles between two receptor units in the interlocked complexes depended on the geometries of TBA cations and the resulting packing structures. Two nonorthogonally arranged planes induced P- and M-form chiral geometries, providing diverse arrangements of chiral species according to crystal polymorphs. Furthermore, the stabilities of the three polymorphs were examined by interfragment interaction energies, which were calculated by ab initio electronic structure calculations using the fragment molecular orbital (FMO) method.
authors.affiliation: Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University , Kusatsu 525-8577, Japan.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Yamakado
authors.affiliation: Department of Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba , Tsukuba 305-8577, Japan.
authors.forename: Ryuma
authors.initials: R
authors.lastname: Sato
authors.affiliation: Department of Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba , Tsukuba 305-8577, Japan.
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Shigeta
authors.affiliation: Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University , Kusatsu 525-8577, Japan.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Maeda