Spectroscopic investigation of size-dependent CO2 binding on cationic copper clusters: analysis of the CO2 asymmetric stretch

A M Reider; M Szalay; J Reichegger; J Barabás; M Schmidt; M Kappe; T Höltzl; P Scheier; O V Lushchikova

doi:10.1039/d4cp01797h

Spectroscopic investigation of size-dependent CO₂ binding on cationic copper clusters: analysis of the CO₂ asymmetric stretch

Phys Chem Chem Phys. 2024 Jul 31;26(30):20355-20364. doi: 10.1039/d4cp01797h.

Authors

A M Reider¹, M Szalay^{2

3}, J Reichegger¹, J Barabás², M Schmidt¹, M Kappe¹, T Höltzl^{2

3}, P Scheier¹, O V Lushchikova¹

Affiliations

¹ Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, Innsbruck 6020, Austria. [email protected].
² HUN-REN-BME Computation Driven Chemistry Research Group, Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Muegyetem rkp. 3, Budapest 1111, Hungary.
³ Furukawa Electric Institute of Technology, Késmárk Utca 28/A, Budapest 1158, Hungary.

Abstract

Photofragmentation spectroscopy, combined with quantum chemical computations, was employed to investigate the position of the asymmetric CO₂ stretch in cold, He-tagged Cu_n[CO₂]⁺ (n = 1-10) and Cu_n[CO₂][H₂O]⁺ (n = 1-7) complexes. A blue shift in the band position was observed compared to the free CO₂ molecule for Cu_n[CO₂]⁺ complexes. Furthermore, this shift was found to exhibit a notable dependence on cluster size, progressively redshifting with increasing cluster size. The computations revealed that the CO₂ binding energy is the highest for Cu⁺ and continuously decreases with increasing cluster size. This dependency could be explained by highlighting the role of polarization in electronic structure, according to energy decomposition analysis. The introduction of water to this complex amplified the redshift of the asymmetric stretch, showing a similar dependency on the cluster size as observed for Cu_n[CO₂]⁺ complexes.