Site-Selective Ligand Functionalization Reverses Hypsochromic Luminescence Shifts in Platinum(II) Complexes of Benzannulated NCN-Coordinating Ligands.

ABSTRACT: Ligands containing phenanthridine (benzo[c]quinoline) have presented notable exceptions to the conventional logic that increasing ligand benzannulation leads to bathochromic (red) shifts in the absorption and emission of their coordination complexes. The counterintuitive blue shifts have been attributed to the peculiar structure of phenanthridines, whose ground states are dominated by imine-bridged biphenyl resonance contributors. These serve to isolate the C=N unit electronically from the rest of the ligand framework and allow the C=N moiety to act as a 'shock-absorber', buffering against larger molecular distortions in a molecule's excited state, and reducing the observed pseudo-Stokes' shift. Here, we provide experimental evidence for this assertion in the form of a counterfactual that

SUBMITTER: Ortiz RJ 

PROVIDER: S-EPMC11771731 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature