Anion-controlled assemblies of C–H⋯O hydrogen bonded grid, stair or bilayer structures by L-shaped pyridinium salts

Abstract

A series of 1-carbamoylmethyl-3-ethoxycarbonylmethylpyridinium salts with different anions (PF₆⁻ (1), BF₄⁻ (2), OTf⁻ (3) and Br⁻ (4)) have been synthesized and characterized by single-crystal X-ray diffraction. The L-shaped pyridinium cation moieties provide rich C–H donors and serve as building blocks to form grid structures with PF₆⁻ and BF₄⁻, a zig-zag stair structure with OTf⁻ and a bilayer structure with Br⁻ anions.