A topologically novel [2]rota[2]catenane containing both a pillar[5]arene-imidazolium based [2]rotaxane subunit and a crown ether-tetracationic cyclophane based [2]catenane one was designed and constructed. The structure of the [2]rota[2]catenane was thoroughly characterized by NMR spectra, MS spectrometry and single crystal X-ray diffraction analysis.

By using the 10BASEd-T, we have synthesized a crown ether-like macrocyclic library possessing randomized peptide linkers on bacteriophage T7. Among 1.5 × 10(9) diversities of the supramolecule candidates, we have obtained a specific binder for the N-terminal domain of Hsp90.

A molecular crank mechanism that enables transformation between rotational and translational motions was designed and synthesized. This molecule consists of a molecular ball bearing as the rotational part in which two disk-shaped rotors can rotate relative to each other through ligand exchange and flipping motion, and a [2]rotaxane as a translational part in which an axle molecule can move back...

The title compound, C(24)H(26)N(4)O(4), is a diaza-crown ether encompassing linked phenylpyrazolyl and benzimidazole units that contribute five atoms to the 16-atom ring. The two planar phenylpyrazolyl and benzimidazole units are aligned at an angle of 66.4 (1)°. The carbonyl O atom of the benzimidazole unit is directed away from the middle of the ring.

The asymmetric unit of the title compound, [K(C(3)H(3)N(2))(C(12)H(24)O(6))], is composed of a potassium cation bonded to the six O atoms of a crown ether mol-ecule and the two N atoms of a pyrazolate anion. The K⋯O distances range from 2.8416 (8) to 3.0025 (8) Å, and the two K⋯N distances are 2.7441 (11) and 2.7654 (11) Å. The K cation is displaced by 0.8437 (4) Å from the best plane through t...

Reaction of the deprotonated N-thiophosphorylated thiourea (4'-benzo-15-crown-5)NHC(S)NHP(S)(OiPr)(2) (HL) with NiCl(2) in aqueous EtOH leads to dark green [Ni(L-1,5-S,S')(2)]·2H(2)O crystals that were isolated by recrystallization from a mixture of CH(2)Cl(2) and n-hexane.

In the title compound, C(6)H(7)ClN(+)·ClO(4) (-)·C(12)H(24)O(6), the cation forms a 1:1 complex with the crown ether, viz [C(6)H(7)ClN-(18-crown-6)](+), in which the -NH(3) (+) unit nests in the crown and inter-acts with it through bifurcated N-H⋯O hydrogen bonding. All constituents of the structure have crystallographically imposed mirror symmetry except for the H atoms of the -NH(3) (+) group...

We used tandem ion mobility spectrometry measurements to investigate how the photo-isomerization of a chromophore (a methylpyridinium derivative) is affected by the complexation with a crown ether. A dramatic blue-shift of the photo-isomerization spectrum was observed upon complexation, which could be well reproduced by ab initio calculations. Our results support that the observed changes in th...

Two procedures for the synthesis of benzo-21-crown-7 have been explored. The [1+1] macrocyclization with KBF₄ as the template was found to be more efficient than the intramolecular macrocyclization without template. Pseudorotaxanes form with secondary ammonium ions bearing at least one alkyl chain narrow enough to slip into the crown ether. Substitution on benzo-21-crown-7 or on the secondary a...

The transport of Pb2+ through a sensory gel, a polymerized crystalline colloidal array hydrogel with immobilized benzo-18-crown-6, is important for understanding and optimizing the sensor. Square wave voltammetry at a Hg/Au electrode reveals many parameters. The partition coefficient for Pb2+ into a control gel (no crown ether), K(p), is 1.00 +/- 0.018 (errors reported are SEM). The porosity, e...