Malonate Crown Ethers as Building Blocks for Novel D-pi-A Chromophores

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 Mg2+ and Eu3+, 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.