Monoribbed‐Functionalized Macrobicyclic Iron( II ) Complexes Decorated with Terminal Reactive and Vector Groups: Synthetic Strategy, Chemical Transformations and Structural Characterization

Comprehensive Summary

General and straightforward synthetic strategy towards the iron(II) clathrochelates with functionalizing substituents in their apical capping and one of the three chelate ribbed fragments was developed. Their hexachloroclathrochelate precursors were prepared by the direct template condensation of dichloroglyoxime with a suitable boronic acid on the Fe²⁺ ion as a matrix and underwent a stepwise nucleophilic substitution with S₂‐, N₂‐ or O₂‐bis‐nucleophiles, forming the alicyclic or aromatic N₂‐, S₂‐ or O₂‐six‐membered fragments. Depending on the reaction conditions and precursor‐to‐dinucleophile molar ratios, iron(II) clathrochelates with one (S, O and N), two (S, O and N) or three (S and O) X₂‐six‐membered ribbed substituent(s) were obtained. Their reactivity substantially decreases in a row: Cl₆‐Cage > Cl₄X₂‐Cage (where X = S, O or, especially, N) > Cl₂X₄‐Cage (where X = S or O). The reactive monoribbed‐functionalized clathrochelates underwent further chemical transformations giving the target macrobicyclic complexes with terminal vector groups. As follows from the single crystal XRD data, their FeN₆‐coordination polyhedra possess the geometry intermediate between a trigonal prism and a trigonal antiprism (φ = 21.3°—25.20°). Fe—N distances vary from 1.887(6) to 1.933(8) Å. Their 3D‐molecules, the hydrophobic–hydrophilic balance in which can be tuned using a ribbed functionalization, form in the crystals the intermolecular specific halogen bonds and/or hydrophobic interactions.