Self‐assembly of daisy chain oligomers from heteroditopic molecules containing secondary ammonium ion and crown ether moieties

MALDI‐TOF MS of the heteroditopic compound 2 ‐(benzylammoniomethyl)dibenzo‐24‐crown‐8 hexafluorophosphate ( 4 ) revealed oligomeric “daisy chain” species up to the hexamer. Similar results were obtained for 2‐(6′‐hydroxyhexylammoniomethyl)dibenzo‐24‐crown‐8 hexafluorophosphate ( 8 ). The complexations of two substituted dibenzylammonium salts, 2,2′‐dimethyldibenzylammonium hexaflurophosphate ( 9a ) and 2,2′,5‐trimethoxydibenzylammonium hexafluorophosphate ( 9b ), with dibenzo‐24‐crown‐8 were examined as models for slippage systems; association constants are reported for these systems. A crystal structure is reported for the new dimethylbenzylammonoium pseudorotaxane. The trimethoxy analog is shown to be capable of slippage formation of a rotaxane, albeit in low yield.