ETD

• Copper tetraphenyl porphyrin
• Magnetic Circular Dischorism
• Magneto-optical spectroscopy

Magnetic Circular Dichroism (MCD) has already been employed to demonstrate the enhancement of the magneto-optical response for a TbPc2 molecular complex, but a detailed description of the influence of all physico-chemical degrees of freedom is still lacking.
In this work, we aim to fill this gap by investigating copper tetraphenylporphyrin (CuTPP) via MCD spectroscopy exploring two routes: studying the interaction of CuTPP films of different thickness on plasmonic nanodisks deposited by thermal evaporation and the supramolecular ordering of CuTPP films on glass deposited by spin-coating. CuTPP is a simple molecular system, suitable for applications in magneto-optical spectroscopy thanks to the electronic configuration of the metal cation.
In the first case, the films are deposited on gold and silver nanodisks and subsequently characterized by absorption spectroscopy, room temperature MCD at 1 T and cryogenic temperature MCD (down to 2 K and up to 10 T). We observe an amplification of the CuTPP response and the variation of the relative intensity of the peaks in the Q-band of the spectrum, around 550 nm.
In the second case, we assess the impact of supramolecular organization obtained by solvent annealing, which consists in exposing the films to a saturated atmosphere of chloroform vapor. This enables a local reorganization which enhances the magneto-optical activity. The same magneto-optical spectroscopic analysis was then repeated on these films prior to and after the annealing.