Anharmonicity in a double hydrogen transfer reaction studied in a single porphycene molecule on a Cu(110) surface

Liu, S, Baugh, D, Motobayashi, K, Zhao, X, Levchenko, SV, Gawinkowski, S, Waluk, J, Grill, L, Persson, M ORCID: 0000-0002-1443-9490 and Kumagai, T (2018) Anharmonicity in a double hydrogen transfer reaction studied in a single porphycene molecule on a Cu(110) surface. PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 20 (17). pp. 12112-12119.

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Abstract

Anharmonicity plays a crucial role in hydrogen transfer reactions in hydrogen-bonding systems, which leads to a peculiar spectral line shape of the hydrogen stretching mode as well as highly complex intra/intermolecular vibrational energy relaxation. Single-molecule study with a well-defined model is necessary to elucidate a fundamental mechanism. Recent low-temperature scanning tunnelling microscopy (STM) experiments revealed that the cis↔cis tautomerization in a single porphycene molecule on Cu(110) at 5 K can be induced by vibrational excitation via an inelastic electron tunnelling process and the N-H(D) stretching mode couples with the tautomerization coordinate [Kumagai et al. Phys. Rev. Lett. 2013, 111, 246101]. Here we discuss a pronounced anharmonicity of the N-H stretching mode observed in the STM action spectra and the conductance spectra. Density functional theory calculations find a strong intermode coupling of the N-H stretching with an in-plane bending mode within porphycene on Cu(110).

Item Type:	Article
Depositing User:	Symplectic Admin
Date Deposited:	30 Apr 2018 07:41
Last Modified:	19 Jan 2023 06:35
DOI:	10.1039/c8cp00178b
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3020712