Premium
Tailoring the Optical Properties of Organic D‐π‐A Photosensitizers: Effect of Sulfur Introduction in the Acceptor Group
Author(s) -
Bettucci Ottavia,
Franchi Daniele,
Sinicropi Adalgisa,
di Donato Mariangela,
Foggi Paolo,
Fabrizi de Biani Fabrizia,
Reginato Gianna,
Zani Lorenzo,
Calamante Massimo,
Mordini Alessandro
Publication year - 2019
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201801497
Subject(s) - chemistry , thioamide , sulfur , photochemistry , dye sensitized solar cell , acceptor , electrolyte , functional group , oxygen , absorption (acoustics) , nanocrystalline material , organic chemistry , crystallography , physics , electrode , acoustics , condensed matter physics , polymer
In this work, we present for the first time the synthesis and characterization of potential DSSC organic sensitizers whose cyanoacrylic acceptor/anchoring group was modified by replacement of oxygen with one or more sulfur atoms. Using known carboxylic acid dye DF15 as a reference, their TD‐DFT computational analysis indicated that oxygen‐sulfur substitution should induce a significant red‐shift of the corresponding UV/Vis absorption spectra. Whereas synthesis of monothiocarboxylic derivatives of DF15 was successfully carried out, isolation of the analogous dithiocarboxylic acid proved impossible due to its very low stability: despite that, their relative spectroscopic properties could be compared by analyzing the corresponding benzylic esters. Combined computational and transient absorption spectroscopy studies suggested that photoexcited thiocarboxylic acid 1‐SO and thioamide 1‐SN were able to inject electrons into nanocrystalline TiO 2 and indicated a similar charge injection efficiency for 1‐SO relative to DF15 . Preliminary DSSC studies showed that, when tert ‐butylpyridine was present in the electrolyte solution, 1‐SO was rapidly degraded; however, in the absence of basic additives 1‐SO provided a sufficiently stable device, giving a slightly lower efficiency compared to carboxylic sensitizer DF15 .