Fused Metallo-Carbaporphyrin-Embedded Graphene Nanoribbon Segments.

-carbaporphyrin-embedded GNR segment displays intense absorption features in the NIR-II spectral region and a ligand-to-metal charge transfer (LMCT) excited state that relaxes predominantly through nonradiative decay. The rigid Pd-incorporated backbone imparts photo- and thermal stability, effectively addressing the susceptibility to photodegradation typical of organic NIR-II dyes. It also benefits from an LMCT-driven relaxation pathway that allows high photothermal conversion efficiencies (PCEs) to be achieved under photoirradiation at either 980 or 1064 nm. The present study provides new insights into solution-phase syntheses of atomically precise porphyrinoid-GNR hybrids, particularly those that feature metal centers.