Abstract
We present six bismuth complexes (NC(R)N)BiX(2) (X = Cl, I) with diarylamine-modified pincer ligands (NC(R)N = (4-R-C(6)H(4))(2)N-C(6)H(2)-(CH(2)NMe(2))(2)-1,3; R = Me, O, NMe(2)) and report on their optoelectronic, photophysical, and electrochemical properties. The complexes exhibit intriguing photophysical behavior, with the p-tolyl and p-anisyl derivatives showing phosphorescence at 77 K in frozen solvent matrices and at room temperature (r.t.) in the solid state. In THF solutions at r.t., only ligand-based fluorescence is observed with strongly reduced quantum yields compared to free proligands NCH(R)N. Electrochemical studies reveal up to three reversible one-electron oxidations. The NMe(2)-substituted complexes display the lowest oxidation potentials and the largest number of redox waves. Radical cations [NCH(NMe2)N](+) and [(NC(NMe2)N)BiX(2)](+) are chemically stable and fluoresce weakly in the near-infrared (NIR) at ca. 1200 nm.