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