Optimal arrangements of 1,3-diphenylisobenzofuran molecule pairs for fast singlet fission

0509458 - ÚOCHB 2020 RIV FR eng J - Journal Article
Buchanan, E. A. - Michl, Josef
Optimal arrangements of 1,3-diphenylisobenzofuran molecule pairs for fast singlet fission.
Photochemical & Photobiological Sciences. Roč. 18, č. 9 (2019), s. 2112-2124. ISSN 1474-905X. E-ISSN 1474-9092
Institutional support: RVO:61388963
Keywords : exciton fission * Hartree-Fock * thin films
OECD category: Physical chemistry
Impact factor: 2.831, year: 2019
Method of publishing: Limited access
https://pubs.rsc.org/en/content/articlelanding/2019/PP/C9PP00283A#!divAbstract

A simplified version of the frontier orbital model has been applied to pairs of C-2, C-2v, C-s, and C-1 symmetry 1,3-diphenylisobenzofuran rotamers to determine their best packing for fast singlet fission (SF). For each rotamer the square of the electronic matrix element for SF was calculated at 2.2 x 10(9) pair geometries and a few thousand most significant physically accessible local maxima were identified in the six-dimensional space of mutual arrangements. At these pair geometries, SF energy balance was evaluated, relative SF rate constants were approximated using Marcus theory, and the SF rate constant k(SF) was maximized by further optimization of the geometry of the molecular pair. The process resulted in 142, 67, 214, and 291 unique geometries for the C-2, C-2v, C-s, and C-1 symmetry molecular pairs, respectively, predicted to be superior to the C-2 symmetrized known crystal pair structure. These optimized pair geometries and their triplet biexciton binding energies are reported as targets for crystal engineering and/or covalent dimer synthesis, and as possible starting points for high-level pair geometry optimizations.
Permanent Link: http://hdl.handle.net/11104/0300198