1 research outputs found
Control over Photoinduced Energy and Electron Transfer in Supramolecular Polyads of Covalently linked azaBODIPY-Bisporphyrin ‘Molecular Clip’ Hosting Fullerene
A ‘molecular clip’ featuring a near-IR
emitting fluorophore,
BF<sub>2</sub>-chelated tetraarylazadipyrromethane (aza-BODIPY) covalently
linked to two porphyrins (MP, M = 2H or Zn) has been newly synthesized
to host a three-dimensional electron acceptor fullerene via a ‘two-point’
metal–ligand axial coordination. Efficient singlet–singlet
excitation transfer from <sup>1</sup>ZnP* to aza-BODIPY was witnessed
in the dyad and triad in nonpolar and less polar solvents, such as
toluene and <i>o</i>-dichlorobenzene, however, in polar
solvents, additional electron transfer occurred along with energy
transfer. A supramolecular tetrad was formed by assembling bis-pyridine
functionalized fullerene via a ‘two-point’ metal–ligand
axial coordination, and the resulted complex was characterized by
optical absorption and emission, computational, and electrochemical
methods. Electron transfer from photoexcited zinc porphyrin to C<sub>60</sub> is witnessed in the supramolecular tetrad from the femtosecond
transient absorption spectral studies. Further, the supramolecular
polyads (triad or tetrad) were utilized to build photoelectrochemical
cells to check their ability to convert light into electricity by
fabricating FTO/SnO<sub>2</sub>/polyad electrodes. The presence of
azaBODIPY and fullerene entities of the tetrad improved the overall
light energy conversion efficiency. An incident photon-to-current
conversion efficiency of up to 17% has been achieved for the tetrad
modified electrode