Directly 2,12- and 2,8-Linked ZnII Porphyrin Oligomers: Synthesis, Optical Properties, and Coherence Lengths

Directly 2,12‐ and 2,8‐linked ZnII porphyrin oligomers were prepared from 2,12‐ and 2,8‐diborylated ZnII porphyrin by a cross platinum‐induced coupling with a 2‐borylated ZnII porphyrin end unit followed by a triphenylphosphine (PPh3)‐mediated reductive elimination. Comparative studies on the steady‐state absorption and fluorescence spectra and the fluorescence lifetimes led to a conclusion that the exciton in the S1 state is delocalized over approximately four and two ZnII porphyrin units for 2,12‐ and 2,8‐linked ZnII porphyrin arrays, respectively. Linked‐in: 2,8‐Linked and 2,12‐linked ZnII porphyrin oligomers have been prepared by utilizing a reaction sequence, including transmetalation with [Pt(cod)Cl2] followed by PPh3‐mediated reductive elimination. Comparative studies on the optical properties revealed that the exciton in the S1 state is delocalized over four and two porphyrin units for 2,12‐ and 2,8‐linked ZnII porphyrin oligomers, respectively.