Recent advances in mono- and multi-nuclear photoluminescent Cu(i) complexes with nitrogen containing ligands and their stimuli responsiveness

Luminescent Cu(i)-derivatives represent a highly desirable alternative to their noble metal analogues in view of copper's relative abundance and low environmental concerns while maintaining large color tunability, high quantum yield and low photo-thermal lability. Moreover, the large variety of structural forms, spanning from 0D mononuclear to 3D polynuclear compounds characterized by peculiar emissive features, opens the door to an incredibly huge family of Cu(i) derivatives with potential application in many different fields. The present review focuses on luminescent neutral 0D mono-, di-, tri- and tetranuclear Cu(i) complexes with N-donor ligands developed during the period 2020 to mid-2025. After a general overview, specific sections are dedicated to members of each nuclearity. Emphasis is given to compounds' stimuli responsiveness, in particular towards vapour exposure and thermal and mechanical perturbations.