Synthesis, Characterization and Remarkable Nonlinear Absorption of a Pyridyl Containing Symmetrical Porphyrin-Polyoxometalate Hybrid

In this manuscript, a pyridyl containing porphyrin, C46H36N8O4 (denoted as Tris@NTPP) and its derived polyoxometalate-porphyrin hybrid, [C4H9)(4)N](3)[C41H26N7NHCO(NH)C(OCH2)(3)MnMo6 O-18(OCH2)(3)C(NH)CONHN7 H26C41] (denoted as NTPP@POM) in which two pyridyl containing porphyrin moieties hanged onto one Anderson polyoxometalate, have been successfully synthesized and thoroughly characterized. Fluorescence quenching was observed in NTPP@POM as compared with its precursor Tris @NTPP inferring the transfer of electron/energy from porphyrin moiety to POM moiety. NTPP@POM showed notably enhanced nonlinear absorption (beta = 2.32 x 10(-5) esu) than Tris @NTPP (beta= 0.73 x 10(-5) esu). These NLO responses were associated with fluorescence decay mechanism which oriented the singlet excited(*S) states and triplet excited(*T) states of Tris@NTPP and NTPP@POM. Life time decay studies revealed that NTPP@POM (tau(2) = 5.32 ns) were stayed for shorter time in excited triplet state than Tris@NTPP (tau(2) =10 ns), implying shorter life time led towards higher NLO responses. [GRAPHICS] .

Automated summary

In this study, a pyridyl containing porphyrin and its derived polyoxometalate-porphyrin hybrid were synthesized and compared. The hybrid showed enhanced fluorescence quenching and nonlinear absorption compared to the precursor, indicating potential applications in nonlinear optics.