Fluorinated meso-tetraaryl Pt(II)-porphyrins: structure, photophysical, electrochemical, and phosphorescent oxygen sensing studies

Fluorinated Pt(II)-porphyrins (F1-F8) were synthesized, characterized; photophysical and electrochemical studies were conducted. The electronic absorption spectra of the complexes exhibited an intense Soret band (392-402 nm) and two hypsochromically shifted visible (Q) bands (508-510 and 538-541 nm). They also exhibited two emission bands (701-721 nm and 651-658 nm), corresponding to the T -> S-0 transition. The cyclic voltammetric studies of the porphyrins revealed the order of electron deficiency is as follows; F2 > F7 approximate to F8 > F5 > F4 > F3. The crystals of F3, F4, and F7 were structurally characterized and the crystal packing was mainly controlled by F center dot center dot center dot H, O center dot center dot center dot H, O center dot center dot center dot O, C center dot center dot center dot H close contacts. The oxygen sensing studies of the synthesized Pt(II)-porphyrins demonstrate that the highest sensitivity was observed for F8 compared to other complexes. The modified Stern-Volmer or two-site model provides the highest weighted quenching constant (K-SV) of 0.068 Torr(-1) for F8, which is twofold of the reference compound F1.