Anion-Orchestrated Formation in the Crystalline State of [2]Pseudorotaxane Arrays

In contrast with dibenzo[24]crown-8 (DB24C8), when tetrabenzo[24]crown-8 (TB24C8) is mixed with dibenzylammonium hexafluorophosphate (DBA·PF 6 ) in noncompetitive solvents, the thermodynamically driven noncovalent synthesis of the threaded 1:1 complex a [2]pseudorotaxane does not occur. However, on crystallization from solution in a process which is presumably kinetically controlled TB24C8 molecules and DBA + cations form an array of [2]pseudorotaxanes stabilized by a plethora of [C−H···F] hydrogen bonds to highly ordered, interstitially located PF 6 - anions.