Synthesis and structures of π-extended [n]Cyclo-para-phenylenes (n = 12, 16, 20) containing n/2 nitrogen atoms

Abstract

[n]Cyclo-para-phenylene congeners of n = 12, 16, 20 with n/2 nitrogen atoms were synthesized via Pt-mediated one-pot macrocyclization reactions. The reaction allowed diversification of participating arylene numbers to afford a series of nanohoop molecules. Spectroscopic analyses in solution showed arylene rotations, and crystallographic analyses in crystals revealed an interesting packing motif. The nanohoop molecules were interwoven by the alkyl substituents in a thread-in-bead manner to form nanoporous packing structures in the crystal.