Axle length- and solvent-controlled construction of (pseudo)[1]rotaxanes from mono-thiourea-functionalised pillar[5]arene derivatives

A series of thiourea-functionalised pillar[5]arene derivatives <b>3</b>^<b>n</b><b>m</b> were constructed from a series of mono-amide-functionalised pillar[5]arenes <b>2</b>^<b>n</b>. The formation of their free forms or (pseudo)[1]rotaxane structures were controlled by their axle lengths or solvents, which were investigated by ¹H NMR spectroscopy. Some of (pseudo)[1]rotaxane structures were also supported by their single-crystal structures.