2019

Controllable Charge-Transfer Mechanism at Push–Pull Porphyrin/Nanocarbon Interfaces

Controllable Charge-Transfer Mechanism at Push–Pull Porphyrin/Nanocarbon Interfaces
Pınar Arpaçay, Partha Maity, Ahmed M. El-Zohry, Alina Meindl, Sevilay Akca, Shane Plunkett, Mathias O. Senge, Werner J. Blau, Omar F. Mohammed
J. Phys. Chem. C
Pınar Arpaçay, Partha Maity, Ahmed M. El-Zohry, Alina Meindl, Sevilay Akca, Shane Plunkett, Mathias O. Senge, Werner J. Blau, Omar F. Mohammed
Push–pull porphyrins, Push–Pull Porphyrin/Nanocarbon Interfaces
2019
​Push−pull porphyrins are made of an electron donor (D), an electron acceptor (A), and a conjugated bridge connecting the D and A units. The tunability of their highest occupied molecular orbital (HOMO)−lowest unoccupied molecular orbital (LUMO) gap can modulate their inter- and intramolecular charge-transfer (CT) and charge-separation (CS) characteristics and their reaction mechanism. Here, ultrafast charge transfer at the interfaces between 5,15-donor−acceptor push−pull porphyrins (Por-tBu and Por-OC8) and nanocarbon materials in the form of fullerene (C60) and graphene carboxylate (GC) are investigated using steady-state and pump−probe spectroscopic techniques. The strong photoluminescence (PL) quenching of the porphyrin indicates an electron transfer from the photoexcited porphyrin to the nanocarbon materials. The results of steady-state and time-resolved experiments reveal that a static and both static and dynamic electron transfer are dominant in the presence of GC and C60, respectively. This work provides new physical insights into the electron-transfer process and its driving force in donor−acceptor systems that include nanocarbon materials.
DOI: 10.1021/acs.jpcc.9b03718