Luminescent Charge-Neutral Copper(I) Phenanthroline Complexes with Isocyanoborate Ligand

Copper(I) complexes with thermal activated delayed fluorescence (TADF) have attracted considerable attention for the development of emissive materials in organic light-emitting devices. However, many emissive Cu^I complexes are cationic emitters and cannot be vacuum-sublimed, a process used for device fabrication. This has limited their applications in devices. In this work we have developed a series of emissive charge-neutral Cu^I complexes with the general formula [Cu(2,9-Me₂phen)(CNR){CNB(C₆F₅)₃}] [R = 2,6-Me₂C₆H₃, 2,6-iPr₂C₆H₃, 2,4,6-Cl₃C₆H₂, 2,4,6-Br₃C₆H₂, 3,5-(CF₃)₂C₆H₃, 4-SF₅C₆H₄] through the incorporation of a strong π-accepting anionic isocyanoborate ligand. All the complexes have been structurally characterized and their photophysical properties have been studied.