The immobilization of functional metal complexes onto polymer supports remains one of the most important research areas. In this study, we prepared spiroborate supramolecular and peapod polymers containing a cationic photoluminescent ruthenium(ii) complex. The supramolecular polymer was obtained by mixing spiroborate cyclic trimer bearing homoallyl group and a ruthenium(ii) tris(bipyridyl) complex, and was further converted into the corresponding peapod polymer by olefin metathesis polymerization. The structure of these polymers was determined by 1H NMR, dynamic light scattering, inductively coupled plasma-atomic emission spectroscopy, energy dispersive X-ray analyses, and atomic force microscopy. The absorption and emission behaviors of the ruthenium(ii) complex were almost the same for the free form and the supramolecular polymer in the mixed solvent of N,N-dimethylformamide and chloroform, although the emission intensity decreased when the chloroform portion was increased. On the other hand, the hypsochromism was observed upon the emission of the ruthenium(ii) complex in the peapod polymer, probably due to the rigidochromic effect of the tight encapsulation by the peapod structure.

A tricationic tris(pyridylpalladium(II)) metallacyclophane was prepared from 3,5-dibromopyridine by a successive treatment with tetrakis(triphenylphosphine)palladium(0), diphosphine, and silver salt. Single-crystal X-ray diffraction analysis revealed that the metallacyclophane incorporated one of three counter anions into its hole-shaped cavity to form multidentate C-H⋯anion interactions. Solution-phase 1H NMR experiments in DMSO-d6 indicated that the metallacyclophane exhibited selective binding behavior toward nitrate, tetrafluoroborate, p-toluenesulfonate, perchlorate, and hydrogen sulfate ions, whereas the hexafluoroantimonate ion exhibited only weak interaction toward the metallacyclophane. This anion recognition behavior was further demonstrated by an extraction experiment of water-soluble sulfonate dyes.

Direct construction of anionic hexakis(spiroborate) prismatic cages was realized by the reaction of hexahydroxytriphenylene, bis(dihydroxynaphthalene)s, and boric acid.

N-Phenylbenzenesulfonamides exist preferentially in (+)-or (-)-synclinal conformations, which place the aromatic rings at both ends in the same direction with a twist. We have systematically analyzed the crystal structure of secondary aromatic sulfonamides bearing methyl, ethyl, and/or methoxy groups on the benzene rings. Intermolecular hydrogen bonding between the sulfonamide protons and sulfonyl oxygens was observed in 81 out of 85 crystals. The intermolecular hydrogen-bonding patterns could be classified into four types, i.e. Dimeric, Zigzag, Helical, and Straight patterns, with retention of the synclinal conformation of the sulfonamide moiety. We investigated the relationship between the hydrogen-bonding pattern and the proportion of the compounds that show chiral crystallization. On the basis of our classification of the intermolecular hydrogen bonds of aromatic sulfonamides, the crystals with Dimeric and Zigzag patterns, which both have enantiomeric synclinal conformers, intrinsically become achiral, except for kryptoracemates. In contrast, a high proportion of compounds with Helical or Straight patterns in the crystals showed chiral crystallization. Our classification is useful for discussion regarding the chirality of molecular assemblies, on the basis of the conformational chirality of the molecules in the crystal.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

To explore the utility of bis(dihydroxynaphthalene) ligands for the construction of supramolecular structures, we demonstrated the preparation of cage-shaped complexes by combining these ligands with hexacoordinate titanium(IV). The reaction of biphenylenebis(dihydroxynaphthalene) with TiO(acac)2 proceeded in the presence of N-methylmorpholine in DMF and an M2L3-type cage was obtained by self-organization. As an extension of this work, the preparation of heterobimetallic molecular cages was examined by using combinations of titanium(IV), palladium(II) or platinum(II), and pyridyldihydroxynaphthalenes. Ti(IV)/Pd(II) cages were prepared in one pot by treatment of the pyridyldihydroxynaphthalene ligands with TiO(acac)2 followed by PdCl2(MeCN)2. In the preparation of Ti(IV)/Pt(II) cages, platinum(II)-bridged bis(dihydroxynaphthalene) ligands were isolated in advance from the reaction of pyridyldihydroxynaphthalene ligand precursors with K2PtCl4, which were then deprotected and reacted with TiO(acac)2 in the same conditions as those for biphenylenebis(dihydroxynaphthalene). The precise structures of the Ti(IV)/Pd(II) and Ti(IV)/Pt(II) heterobimetallic cages were fully elucidated by X-ray crystallographic analysis.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Twin-bowl-shaped tris-(spiroborate) cyclophanes bearing pyridyl groups have been prepared for the construction of proton-responsive supramolecular polymers. Preparation of the pyridyl twin bowls was carried out by the reaction of 6,6'-(3-pyri dyl)-2,2',3,3'-tetrahydroxy- 1, 1'-binaphthyls and an equimolar amount of boric acid in N,N-dimethylformamide in self-organization manner, as previously reported. The reversible acid/base response of the pyridyl twin bowls was evaluated by the addition of hydrochloric acid and aqueous sodium hydroxide. The assembly disassembly modulation of the supramolecular polymers composed of pyridyl twin bowls and the tricationic iridium-(III) complex was also examined. Dissociation of the supramolecular polymers occurred by the addition of hydrochloric acid, and its reconstruction was realized by the addition of aqueous sodium hydroxide. The opposite behavior was observed when the dianionic palladium-(II) complex was employed as a guest. The addition of acid led to the formation of the aggregate that was dissociated by the addition of base.

Successive guest-containing tubular polymer was prepared by the olefin metathesis polymerization of tris(spiroborate) twin bowl after the formation of supra molecular polymer. The cationic iridium(III) complexes were topologically fixed inside the polymer to form a peapod-like structure. The polymer was evaluated by SEC, ICP-AES, and DLS analyses, and string-like structures were found in the AFM observation of the peapod polymer.

N-Substituted-9-aza-3,6,12,15-tetrathiaheptadecanes having Ph-C-N frameworks (N-R-ATH; R = benzyl (N-Bn-ATH), 4-nitrobenzyl (N-NO2Bn-ATH), and diphenylmethyl (N-Ph2CH-ATH)) were synthesized, and their Ag(i) complexes were structurally characterized. X-Ray crystal structure analyses of [Ag(N-R-ATH)](BF4) (R = Bn and Ph2CH) revealed monomeric tetra-S-coordinated complex cation structures without the N-coordination, and a benzene ring of the N-R group covered over the amine nitrogen atom. The precise extraction analyses of a Ag(i) ion with ATH derivatives (L = N-R-ATHs and N-H-ATH) associated with the (1)H NMR analyses of the [Ag(L)](+) complexes in polar and non-polar solvents revealed that the introduction of the N-substituent significantly enhanced the extractability of Ag(+), due to the "hydrophobic cover" effect by the Ph-C-N framework in the [Ag(N-R-ATH)](+) complexes.

The construction of various nanometer-sized cyclophanes has been carried out by the use of reversible formation of spiroborate linkages. Bis(2,3-dihydroxynaphthalene)s were converted into the corresponding cyclic spiroborate timers in the presence of equimolar amount of boric acid in N,N-dimethylformamide. The cyclic trimer of 2,2',3,3'-tetrahydroxy-1,1'-binaphthyl possessed a crown-ether-like cavity and exhibited selective recognition toward potassium or barium cations. This cyclic trimer also had bowl-shaped cavities at both sides of its symmetry plane, and acted as a ditopic host that iteratively recognized spherical cationic complex to form a supramolecular polymer structure. Multicomponent construction of cyclic spiroborates was also realized by the combination of oligo(2,3-dihydroxynaphthalene)s and 2,3,6,7-tetrahydroxy-9,10-anthraquinone. It was found that the rectangular-shaped spiroborate nanocycles were constructed in a self-organization manner and exhibited characteristic molecular recognition behavior toward cationic aromatic guests.

Multicomponent construction of the tetrakis(spiroborate) anionic nanocycles was achieved by reacting bis(dihydroxynaphthalene)s with tetrahydroxyanthraquinone in the presence of boric acid in a self-organized manner. These nanocycles exhibited selective molecular recognition behavior toward cationic guests such as methyl viologen derivatives. Formation of a supramolecular ring@ring and a guest@ring@ring structure was observed by combining the anionic nanocycle and the vinylogous analog of cyclobis(paraquat-p-phenylene).

Multilayered spiroborate nanocycles were prepared from tris- or tetrakis(dihydroxynaphthalene) and tetrahydroxyanthraquinone as pillar and crossbar units via the reversible formation of a spiroborate linkage. The four-layered spiroborate nanocycle recognized two cationic aromatic guests simultaneously and exhibited the ability to form a supramolecular one-dimensional array by combining with methyl viologen dimer as the ditopic guest.