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M. Corva, A. Ferrari, M. Rinaldi, Z. Feng, Matteo Roiaz, Ch. Rameshan, G. Rupprechter, R. Constantini, M. Dell´Angela, G. Pastore, G. Comelli, N. Seriani, E. Vesselli:
"Vibrational fingerprint of localized excitons in a two-dimensional metal-organic crystal";
Nature Communications, 9 (2018), (#?).

Long-lived excitons formed upon visible light absorption play an essential role in photovoltaics, photocatalysis, and even in high-density information storage. Here, we describe a self-assembled two-dimensional metal-organic crystal, composed of graphene-supported
macrocycles, each hosting a single FeN₄ center, where a single carbon monoxide molecule can adsorb. In this heme-like biomimetic model system, excitons are generated by visible laser light upon a spin transition associated with the layer 2D crystallinity, and are simultaneously detected via the carbon monoxide ligand stretching mode at room temperature and near-ambient pressure. The proposed mechanism is supported by the results of infrared and time-resolved pump-probe spectroscopies, and by ab initio theoretical methods, opening a path towards the handling of exciton dynamics on 2D biomimetic crystals.

http://dx.doi.org/10.1038/s41467-018-07190-1