Lipophilic Bis(monoaza crown ether) Derivatives: Synthesis and Cation-Complexing Properties

Article abstract of DOI:10.1021/jo00375a041

Eleven lipophilic bis(monoaza crown ether) derivatives <1 and 2 (n = 0 - 3) and 3 (n = 1 - 3)> were synthesized, in which two monoaza crown ethers with 9-, 12-, 15-, or 18-membered rings are linked through the nitrogen atoms by an alkane-, diether-, or diester-type bridge chain bearing a dodecyl group.Sodium and potassium binding with the bis(monoaza crown ether) was determined potentiometrically and compared with those for previous bis(crown ethers) 5 (n = 1 - 3) and corresponding monocyclic analogues 4 and 6 (n = 1 - 3).Marked bis(crown ether) effect was observed only for the alkane-type bis(monoaza-12-crown-4) and bis(monoaza-15-crown-5) derivatives 1 (n = 1,2) on complexing Na⁺ and K⁺, respectively.It was suggested that in some of the other bis(monoaza crown ethers) lariat-ether effect works instead.Bis(monoaza-9-crown-3) derivatives 1 and 2 (n = 0) possess very poor cation-complexing ability.Acidity constant values gave some hints about the bis(crown ether) effect.