Thiacrown Ethers with Oxygen and Sulfur for Coordination: Formation of the Pd and Pt Complexes and Pseudorotaxane with Dialkylammonium

Mono‐, di‐ tri‐, and tetrathiadibenzo[24]crown‐8‐ethers with eight oxygen or sulfur atoms within the 24‐menbered ring have been synthesized by using 1,2‐benzenedithiol and 2‐hydroxythiophenol as the starting materials. The thia[24]crown ethers form [2]pseudorotaxanes with dibenzylammonium salts, the association constants of which vary depending on the numbers and positions of the sulfur and oxygen atoms. The [2]pseudorotaxane of 1,4‐dithiadibenzo[24]crown‐8‐ether (1,4‐DTC) was converted into its Pd complex [PdCl 2 (1,4‐DTC)] by the addition of [PdCl 2 (cod)] (cod = 1,5‐cyclooctadiene), accompanied by the liberation of dibenzylammonium. Subsequent addition of PPh 3 to the mixture led to regeneration of the [2]pseudorotaxane. A [2]pseudorotaxane composed of 1,4‐DTC and dialkylammonium with two vinyl groups at both ends of the axis component underwent a cross‐metathesis reaction with an acrylate ester to form the corresponding [2]rotaxane with an interlocked structure.