Benchmarking the anisotropy of nitroxyl radical solvation with IR spectroscopy


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Bras E. M., Zimmermann C., Fausto R., Suhm M. A.

PHYSICAL CHEMISTRY CHEMICAL PHYSICS, cilt.26, sa.7, ss.5822-5829, 2024 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 26 Sayı: 7
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1039/d3cp05668f
  • Dergi Adı: PHYSICAL CHEMISTRY CHEMICAL PHYSICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, MEDLINE
  • Sayfa Sayıları: ss.5822-5829
  • İstanbul Kültür Üniversitesi Adresli: Evet

Özet

Two simple nitroxyl radicals, di-tert-butyl nitroxyl (DTBN) and 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO) are solvated by one or two water, methanol, tert-butyl alcohol or phenol molecules. The resulting low temperature IR spectra of the vacuum-isolated microsolvates in the OH stretching range are assigned based on harmonic DFT predictions for closed shell solvent dimers and trimers and their offset from experiment, to minimise theory-guided assignment bias. Systematic conformational preferences for the first and second solvent molecule are observed, depending on the conformational rigidity of the radical. These assignments are collected into an experimental benchmark data set and used to assess the spectral predicting power of different DFT approaches. The goal is to find inexpensive computational methods which provide reliable spectral predictions for this poorly explored class of microsolvates. Conformations of organic radical-solvent complexes are vibrationally assigned by comparison to related closed-shell complexes.