Machalska, Ewa Zajac, Grzegorz Gruca, Anna Zobi, Fabio Baranska, Malgorzata Kaczor, Agnieszka 2020-07-02 In this work, cobalamins with different upper axial substituents and a cobalamin derivative with a ring modification were studied using chiroptical spectroscopies, in particular resonance Raman optical activity (RROA), to shed light on the influence of structural modifications on RROA spectra in these strongly chiral systems in resonance with multiple excited states at 532 nm excitation. We have demonstrated that for these unique systems RROA possesses augmented structural specificity, surpassing resonance Raman spectroscopy and enabling at the same time measurement of cobalamins at fairy low concentrations of ∼10–5 mol dm–3. The enhanced structural specificity of RROA is a result of bisignate spectra due to resonance via more than one electronic state. The observation of increased structural capability of RROA for cobalamins opens a new perspective for studying chiral properties of other biological systems incorporating d-metal ions. application/pdf https://folia.unifr.ch/global/documents/308593 https://folia.unifr.ch/documents/308593/files/zob_rro.pdf https://folia.unifr.ch/documents/308593/files/zob_rro_sm.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1021/acs.jpclett.0c01218 info:eu-repo/semantics/openAccess License undefined The Journal of Physical Chemistry Letters. - 2020, vol. 11, no. 13, p. 5037–5043 info:eu-repo/classification/udc/54 Resonance raman optical activity shows unusual structural sensitivity for systems in resonance with multiple excited states: vitamin B12 case http://purl.org/coar/resource_type/c_6501