Influencing the self‐sorting behavior of [2.2]paracyclophane based ligands by introducing isostructural binding motifs

Abstract

Two isostructural ligands with either nitrile ( L nit ) or isonitrile ( L iso ) moieties directly connected to a [2.2]paracyclophane backbone with pseudo‐meta substitution pattern have been synthesized. The ligand itself ( L nit ) or its precursors ( L iso ) were resolved via HPLC on a chiral stationary phase and the absolute configuration of the isolated enantiomers was assigned by XRD analysis and/or by comparison of quantum‐chemical simulated and experimental ECD‐spectra. Surprisingly, the resulting metallosupramolecular aggregates formed in solution upon coordination of [(dppp)Pd(OTf) 2 ] differ in their composition: whereas L nit forms dinuclear complexes L iso exclusively forms trinuclear ones. Furthermore, they also differ in their chiral self‐sorting behavior as ( rac )‐ L iso undergoes exclusive social self‐sorting leading to a heterochiral assembly whereas ( rac )‐ L iso shows a twofold preference for the formation of homochiral complexes in a narcissistic self‐sorting manner as proven by ESI mass spectrometry and NMR spectroscopy. Interestingly, upon crystallization these discrete aggregates undergo structural transformation to coordination polymers as evidenced by single‐crystal X‐ray diffraction.