Selective Ammonia Sensing through Reversible Vapochromism and Luminescence ON-OFF Switching of a Chalcone-Based Co(II) Complex

Abstract

In this work, we demonstrate that a chalcone-based cobalt(II) complex exhibits distinct vapochromism upon exposure to ammonia (NH₃) vapor, accompanied by reversible luminescence ON-OFF switching. The response is triggered by partial dissociation of the chalcone ligand from the cobalt(II) center, concomitant with insertion of NH₃ molecules to the cobalt(II) metal center.