6 research outputs found
Photoelectrochemical and thermal characterization of aromatic hydrocarbons substituted with a dicyanovinyl unit
Seven aromatic hydrocarbons bearing a dicyanovinyl unit were prepared to
determine the relationship between both the number of aromatic rings and location of acceptor
substituent on their thermal and optoelectronic properties. Additionally, the density functional
theory calculations were performed. The obtained compounds showed temperatures of the
beginning of thermal decomposition in the range of 137 – 289 °C, being above their
respective melting points found between 88 and 248 °C. They were electrochemically active
and showed quasi-reversible reduction process (except for 2-(phen-1-
yl)methylene)malononitrile). Electrochemically estimated energy band gaps were below 3.0
eV, in the range of 2.10 – 2.50 eV. The absorption and emission spectra were recorded in
CHCl3 and NMP and in solid state. All compounds strongly absorbed radiation with
absorption maximum ranging from 307 to 454 nm ascribed to the intramolecular charge
transfer between the donor and acceptor units. The aromatic hydrocarbons were luminescent
in all investigated media and exhibited higher photoluminescence quantum yields in the solid
state due to the aggregation induced emission phenomena. Electroluminescence ability of
selected compounds was tested in a diode with guest-host configuration. Additionally, the
selected compound together with a commercial N719 was applied in the dye-sensitized solar
cell