Room-temperature phosphorescence and static excimer excitation of pyrene-modified (NCN) pincer bismuth complexes†

We present the synthesis, characterization, and photophysical properties of two pyrene-modified (NCN) pincer bismuth complexes, where the pyrenyl residues are either part of the cyclometalating pincer ligand (1) or bound as monodentate ligands to the Bi^III ion (2). Both complexes are dually emissive at 77 K. For complex 2, pyrenyl phosphorescence persists at r.t. in degassed CH₂Cl₂, albeit with reduced intensity. This renders 2 one of only a handful of Bi complexes showing this property.