A Combined Experimental and Theoretical Study of ESR Hyperfine Coupling Constants for N,N,N’,N’-Tetrasubstituted p-Phenylenediamine Radical Cations

Ronan Gleeson, Cecilie Lindholm Andersen, Peter Rapta, Peter Machata, Jørn Bolstad Christensen, Ole Hammerich, Stephan P. A. Sauer*

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

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Abstract

A test set of N,N,N’,N’-tetrasubstituted p-phenylenediamines are experimentally explored using ESR (electron spin resonance) spectroscopy and analysed from a computational standpoint thereafter. This computational study aims to further aid structural characterisation by comparing experimental ESR hyperfine coupling constants (hfccs) with computed values calculated using ESR-optimised “J-style” basis sets (6-31G(d,p)-J, 6-31G(d,p)-J, 6-311++G(d,p)-J, pcJ-1, pcJ-2 and cc-pVTZ-J) and hybrid-DFT functionals (B3LYP, PBE0, TPSSh, ω
B97XD) as well as MP2. PBE0/6-31g(d,p)-J with a polarised continuum solvation model (PCM) correlated best with the experiment, giving an R2 value of 0.8926. A total of 98% of couplings were deemed satisfactory, with five couplings observed as outlier results, thus degrading correlation values significantly. A higher-level electronic structure method, namely MP2, was sought to improve outlier couplings, but only a minority of couples showed improvement, whilst the remaining majority of couplings were negatively degraded.
OriginalsprogEngelsk
Artikelnummer3447
TidsskriftInternational Journal of Molecular Sciences (Online)
Vol/bind24
Udgave nummer4
Antal sider17
ISSN1661-6596
DOI
StatusUdgivet - 8 feb. 2023

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