Synthesis and uses of macrobicyclic cryptands: from complexation of transition metal ions to molecular devices

Abstract

Syntheses of a number of cryptands having heteroditopic as well as heterotritopic receptor sites have been achieved using alkali metal ions as templates. Some of the cryptands can be synthesized on a multi-gram scale without using any templating metal ions at low temperature (278 K). Each of these cryptands readily forms inclusion complexes with transition metal ions. These cryptands exhibit interesting properties and can further accomodate small anions inside the cavity. Further, upon suitable derivatization, some of the cryptands can behave as amphiphiles and form Langmuir-Blodgett films very readily. When derivatized with 9-methylanthracene, some of the cryptands show interesting fluorescence properties and can be of use as molecular photonic devices.