Macrocyclic polyether-diester compounds as phase-transfer catalysts

Malonate crown ethers as building blocks for novel D-pi-A chromophores

[reaction: see text] A series of new crown ethers, incorporating a malonate ester functionality, have been synthesized and derivatized with pi-electron rich aldehydes to give, conjugated, extended "push-pull" compounds. Their ability to bind Lewis acid-like metal cations, such as Mg(2+) and Eu(3+), has been characterized, and the relative stability constants are presented. When the metal cation is bound to the malonate moiety within the crown ether cavity, the D-pi-A character of the molecular structure is greatly enhanced.