Heterometallic NIR-emitting nanothermometers by click-reaction between two lanthanide complexes

Abstract

Heterobimetallic lanthanide conjugates were obtained by click-reaction between two monometallic lanthanide complexes with Schiff bases for the first time. For that, novel azido- and ethynyl-substituted ligands, as well as their lanthanide complexes, were obtained and characterised; two new crystal structures were obtained. Click-reaction between ligands and complexes was performed, and the latter was demonstrated to result in the conjugates {Ln₁–Ln₂} formation. Among the obtained conjugates, {Yb–Nd} and {Yb–Er} demonstrated intense NIR emission with temperature sensitivity in the physiological range of up to 3%/K.