Investigation of the Structural and Thermochemical Properties of [2.2.2]-Bicyclooctadiene Photoswitches
Journal article, 2021

Molecular photoswitches can under certain conditions be used to store solar energy in the so-called molecular solar thermal storage systems, which is an interesting technology for renewable energy solutions. The current investigations focus on the performance of seven different density functional theory (DFT) methods (B3LYP, CAM-B3LYP, PBE0, M06-2X, ωB97X-D, B2PLYP, and PBE0DH) when predicting geometries and thermochemical properties of the [2.2.2]-bicyclooctadiene (BOD) photoswitch. We find that all of the investigated DFT methods provide geometries that are in good agreement with those obtained using coupled cluster singles and doubles (CCSD) calculations. The dependence on the employed basis set is not large when predicting geometries. With respect to the thermochemical properties, we find that the M06-2X, CAM-B3LYP, PBE0, and ωB97X-D functionals all predict thermochemical properties that are in good agreement with the results of the CCSD, the CCSD including perturbative triples (CCSD(T)), and the explicitly correlated CCSD-F12 and CCSD(T)-F12 models. Lastly, for energy calculations, we tested the newly developed fourth-order cluster perturbation theory singles and doubles CPS(D-4) model, which in this study provides energy differences that are of CCSD and sometimes also CCSD(T) quality at a relatively low cost. We find that the CPS(D-4) model is an excellent choice for further investigation of BOD derivatives because accurate energies can be obtained routinely using this methodology. From the results, we also note that the predicted storage energies and storage energy densities for the BOD photoswitch are very large compared to other molecular solar thermal storage systems and that these systems could be candidates for such applications.

Author

Andreas Erbs Hillers-Bendtsen

University of Copenhagen

Maria Quant

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Kasper Moth-Poulsen

Catalan Institution for Research and Advanced Studies

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Institute of Material Science of Barcelona (ICMAB)

Kurt V. Mikkelsen

University of Copenhagen

Journal of Physical Chemistry A

1089-5639 (ISSN) 1520-5215 (eISSN)

Vol. 125 48 10330-10339

Molecular Solar Thermal energy storage systems (MOST)

European Commission (EC) (EC/H2020/951801), 2020-09-01 -- 2024-02-29.

Swedish Energy Agency (2019-010724), 2019-05-07 -- 2019-09-03.

Subject Categories

Energy Engineering

Theoretical Chemistry

Energy Systems

DOI

10.1021/acs.jpca.1c07737

PubMed

34809434

More information

Latest update

4/5/2022 5