2019/12/30 by K. Yamashita, Narumi Kuramochi, Hang Pham Qui Van +3 · 1 voice · 1 citation
Materials Science · Chemistry · #Porphyrin and Phthalocyanine Chemistry #Metal-Catalyzed Oxygenation Mechanisms #Luminescence and Fluorescent Materials
paper · doi:10.1002/cplu.201900670
openalex publication_date 2019/12/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/25
Abstract A series of porphyrin dimers bridged by one or two rigid arylenedioxy linkers was successfully synthesized by catalyst‐free meso ‐aryloxylation involving nucleophilic aromatic substitution. The orientational freedom and conformation of the two porphyrin macrocycles in the mono‐bridged dimers depended on the steric hindrance between the macrocycles and substituents on the arylenedioxy linkers. On the other hand, the bis‐bridged dimers exhibited a highly rigid cofacial conformation with a distinct interplanar distance. The fluorescence quantum yields of the bis‐bridged dimers ( Φ fl =0.094 and 0.096) were quite similar to those of the monomers ( Φ fl =0.13). Owing to their high rigidities, the nonradiative deactivation of the photoexcited states associated with dimerization, which are observed for reported dimers, are mostly suppressed, thus suggesting that those dimers have highest rigidities among the cofacial porphyrin dimers exploring emission properties. Cyclic voltammetry revealed the electronic communication between the porphyrin macrocycles in the closely stacked bis‐bridged dimer.