Themed collection Structural Macrocyclic Supramolecular Chemistry

Welcome to this CrystEngComm themed issue on structural macrocyclic supramolecular chemistry.

Assembly strategies used to construct metal–organic capsules are discussed, paying particular attention to their recent application with the emerging p-carboxylatocalixarenes.

In cyclic alpha-peptoids, inter-annular CH⋯OC hydrogen bonds provide face to face or side by side arrangement of macrocycles mimicking the beta-sheet secondary structure in proteins. Side chains may promote the formation of peptoid nanotubes, acting as pillars among neighbouring macrocycles.

The term “synthon engineering” is introduced for the directed manipulation of the molecular packing architecture including the system of secondary interactions caused by the respectively fine tuned synthons.

The synthesis and structural elucidation of copper-seamed C-alkylpyrogallol[4]arene hexamers with different tail lengths (n = 3, 7, 9) reveal differences in packing arrangements.

The conformational properties and self-assembly behaviour of the p-carboxylatocalix[4]arenes are markedly influenced by salt formation with 2-aminopyridine that can also act simultaneously as a template.

Spatially-separated polar channels and non-polar voids were shown to coexist in the crystal of a new type of coordination polymer formed by a hexaazamacrocyclic nickel(II) cation and a lower rim substituted calix[4]arene tetracarboxylate trianion.

We report the synthesis and X-ray structures of a macrocyclic fluorophore that binds water or HCl, accommodating either molecule in nearly identical environments.

We report on the kinetic crystallization of the tubular coordination polymer constructed from cucurbit[6]uril and magnesium ions. The metastable phase spontaneously converts into a thermodynamically favored discrete coordination complex.

C4-H and C5-H protons of the imidazolium heterocycle have been exploited as a binding site for anion recognition.

Lanthanide coordination polymers with ladder-like structures or a decorated kagome dual network are formed from pyridine-N-oxide or carboxylate functionalised cyclotriveratrylene-type ligands.

Two new conformations of para-sulphonato-calix[8]arene have been found in supramolecular complexes with BPE and BPP, the gas take-up has been demonstrated for S8C–BPE complex.

Assembly of a pentameric supramolecular architecture.

Multiple ¹³C NMR resonances for the CO, CH and CH₂ groups in crystalline cucurbituril compounds provide fingerprints for different structures.

The application of “routine” protein molecular replacement method enables solving the crystal structure of a chiral organic capsule.

Combinations of tetrakis meta-pyridyl appended tetrathia- or tetrathiamercapto-calix[4]arene in 1,3-A conformation with MX₂ (M = Cd, Co or Fe, X = Cl or Br), behaving as a neutral metallatecton, lead to 2D grid type and 3D porous diamondoid coordination networks.

The unusual exclusion of smaller guests by host may be avoided by solid-phase exchange in preparation of clathrates, which thus become extremely thermally stable.

A p-sulfonatocalix[4]arene-based, C-shaped supermolecule, [Ce₃(PDA)₄(C4AS)₂·13H₂O](NO₃)·25H₂O 1 was prepared and characterized by single crystal X-ray structural analysis, thermal methods (TG, DSC and hot-stage microscopy) and Hirshfeld analysis.

The deprotonation of a resorcinarene by small organic bases results in 1 : 1 inclusion and 1 : 2 pseudo-capsular ion-pair complexes.

Four new discrete and polymeric coordination compounds have been prepared and analysed, based on two divergent macrocycle-derived ligands bearing pendant carboxylic acid or nitrile functional groups.

Strong halogen bonds are observed in the solid state structures of chloro-, bromo-, and iodoimidazolium macrocycles with bromide and nitrate anions.

A conformationally flexible calix[4]arene exhibits either a porous or a non-porous solid state structure depending on the employed solvent system.