Exploring the spectral properties and potential applications of dimethylamine-modified porphyrin and chlorin dyes

abstract

The synthesis, structural characterization, and optical properties of new free-base and metalated dimethylamine-based porphyrin (1, 1a) and chlorin (2, 2a) derivatives are presented. The synthetic approach is based on the peripheral substitution of the para-fluor atoms of the commercially available 5,10,15,20-tetrakis(pentafluorophenyl)-21H,23H-porphyrin (H2TPPF20) by dimethylamine (H(2)Por 1), following the preparation of the analogous chlorin dye (H(2)Chl 2) using N-methylglycine and p-formaldehyde. Both compounds were then metalated with zinc acetate to perform the corresponding ZnPor 1a and ZnChl 2a dyes. Several photophysical parameters were determined, including absorption and emission features at 298 K (e.g., molar absorptivity coefficients, lambda absorption maxima of Soret and/or Q bands, lambda(emission) maxima, and ratio of long- to short-wavelength emission intensity), fluorescence quantum yield (& Fcy;(F)), stability (under dark conditions), and photostability (under white light exposure at irradiance of 50 mW.cm(-2)). The photophysical results were determined and compared for the type of meso-substituted scaffold selected - A(4)-type - of free-base (1, 2) and zinc(II) complex (1a, 2a). The four compounds exhibit high dark stability in DMF (absorption reduction intensity < 3 %). The Pors 1 and 1a have also high photostability (absorption reduction intensity < 1.5 %), but H(2)Chl 2 and ZnChl 2a present a considerable absorption reduction, 14.3 % and 22.3 %, respectively. The & Fcy;(F) of the ZnPor 1a (& Fcy;(F) = 0.02) and H(2)Por 1 (& Fcy;(F) = 0.02) are lower than those of ZnChl 2a (& Fcy;(F) = 0.06) and H(2)Chl 2 (& Fcy;(F) = 0.09). The developed compounds present potential applications in nonlinear optics, biomarkers, and/or solar cells.

keywords

NONLINEAR-OPTICAL PROPERTIES; PHOTOPHYSICAL PROPERTIES; 1,3-DIPOLAR CYCLOADDITIONS; SOLAR; ISOBACTERIOCHLORINS; FLUORESCENCE; DERIVATIVES; INSIGHTS; SENSORS; DESIGN

subject category

Chemistry

authors

Gamelas, SRD; Rodrigues, JMM; Tomé, JPC; Lourenço, LMO

Groups

G5 - Biomimetic, Biological and Living Materials

Projects

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

acknowledgements

This work received financial support from PT national funds (FCT/MCTES, Fundacao para a Ciencia e a Tecnologia and Ministerio da Ciencia, Tecnologia e Ensino Superior) through projects LAQV-REQUIMTE (LA/P/0008/2020, DOI https://doi.org/10.54499/LA/P/0008/2020; UIDP/50006/2020, DOI https://doi.org/10.54499/UIDP/50006/2020; and UIDB/50006/2020, DOI https://doi.org/10.54499/UIDB/50006/2020), CICECO-Aveiro Institute of Materials (UIDB/50011/2020, DOI https://doi.org/10.54499/UIDB/50011/2020); UIDP/50011/2020, DOI https://doi.org/10.54499/UIDP/50011/2020); and LA/P/0006/2020, DOI https://doi.org/10.54499/LA/P/0006/2020)), CQE (UIDB/00100/2020, DOI https://doi.org/10.54499/UIDB/00100/2020; and UIDP/00100/2020, DOI https://doi.org/10.54499/UIDP/00100/2020), IMS (LA/P/0056/2020, DOI https://doi.org/10.54499/LA/P/0056/2020)), and P2020-PTDC/QUI-QOR/31770/2017. S. Gamelas and J. M. M. Rodrigues thank FCT for the Ph.D. grant (SFRH/BD/143549/2019) and individual researcher contract (DOI https://doi.org/10.54499/CEECIND/01363/2018/CP1559/CT0022), respectively.