Phosphorescent Cyclometalated Palladium(II) and Platinum(II) Complexes Derived from Diaminocarbene Precursors

Abstract

Metal-mediated self-assembly of isocyanides and methyl 4-aminopyrimidine-5-carboxylate leads to luminescent Pd II and Pt II complexes featuring C,N-cyclometalated acyclic diaminocarbene (ADC) ligands. The solid-state luminescent properties of these diaminocarbene derivatives are attributed to their triplet-state metal/metal-to-ligand charge-transfer ( 3 MMLCT) nature, which is driven by attractive intermolecular M•••M interactions further reinforced by the intramolecular π−π interactions even in the structure of the Pd compound, which is the first Pd-ADC phosphor reported. C,N-cyclometalated diaminocarbene-based ligands provides access to unique luminescent Pd II derivatives. The emergence of intermolecular interactions is recognized as a driving force toward the phosphorescence of diaminocarbene complexes described in this work, and our future efforts will be dedicated to a better understanding of the relationship between the molecular construction and luminescence properties of metal aminocarbene species. ■ ASSOCIATED CONTENT * sı Supporting InformationThe Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.inorgchem.3c03346.Experimental section, spectral, XRD, and experimental data, structural features discussion, and theoretical calculations (PDF)Accession Codes