Carboxyester functionalised dye–zeolite L host–guest materials

A procedure for the selective modification of zeolite L channel ends with carboxyl terminated groups is reported. The material was prepared by first grafting organic molecules with a terminal amino group to the channel openings. These were afterwards reacted with the thiourea group of methyl-3-isothiocyanatopropionate. The success of the reaction was tested by means of vibrational spectroscopy, optical microscopy and energy transfer experiments after binding strongly luminescent dyes to the carboxyl groups. The reaction was successfully carried out on 5000 nm and 30 nm sized crystals.