[3]rotaxanes composed of two dibenzo-24-crown-8 ether wheels and an azamacrocyclic complex

• Published in: Dalton transactions : an international journal of inorganic chemistry 2018-11, Vol.47 (44), p.15845-15856
• Main Authors: Wo ny, Mateusz, Wi ckowska, Agnieszka, Trzybi ski, Damian, Sutu a, Szymon, Domaga a, S awomir, Wo niak, Krzysztof
• Format: Article
• Language: English
• Subjects: Acetone; Crystal lattices; Crystallography; Hydrogen bonds; Ions; Mass spectrometry; NMR spectroscopy; Rotaxanes; Shafts (machine elements); Single crystals; X ray spectra; X-ray diffraction
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c8dt03225d

The azamacrocyclic complex was used as a platform for the construction of [3]rotaxanes containing two DB24C8 macrocycles per molecule. The complex unit incorporates two electron deficient π-bond systems and two N-H hydrogen bond donating groups which facilitated the formation of a 1 : 2 interlocked structure. Synthesis and properties of such compounds are presented. Structures of the obtained compounds were confirmed by NMR spectroscopy, ESI mass spectrometry, elemental analysis and single crystal X-ray diffraction. Both [3]rotaxanes containing two DB24C8 macrocycles per molecule crystallise in P 1&cmb.macr; and P 2 1 / n space groups. They have different counterions (PF 6 − and Cl − anions, respectively) and mostly disordered solvent molecules such as water, methanol and acetone. Both [3]rotaxanes have a flexible axle in which the Cl − salt takes the shape closer to the "S"-letter, while in the PF 6 − case the axle is more linear. The shape results from respective packing and intra-, and intermolecular interactions among the moieties in the rotaxane and the crystal lattice. The first [3]rotaxane based on a tetraazamacrocyclic nickel( ii ) complex was synthesized and investigated.