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RESEARCH PRODUCT
Similarity and Specificity of Chlorophyll b Triplet State in Comparison to Chlorophyll a as Revealed by EPR/ENDOR and DFT Calculations
Alessandro AgostiniAlessandro AgostiniLaura OrianMarilena Di ValentinMaria Giulia Dal FarraAntonino PolimenoHarald PaulsenDonatella Carbonerasubject
Chlorophyll bElectron nuclear double resonance010304 chemical physics010402 general chemistry01 natural sciencesTetrapyrrole0104 chemical sciencesSurfaces Coatings and Filmslaw.inventionchemistry.chemical_compoundCrystallographychemistrylaw0103 physical sciencesMaterials ChemistryDensity functional theoryPhysical and Theoretical ChemistryTriplet stateElectron paramagnetic resonanceHyperfine structureMethyl groupdescription
An investigation of the photoexcited triplet state of chlorophyll (Chl) b has been carried out by means of electron nuclear double resonance, both in a frozen organic solvent and in a protein environment provided by the water-soluble chlorophyll protein of Lepidium virginicum. Density functional theory calculations have allowed the complete assignment of the observed hyperfine couplings corresponding to the methine protons and the methyl groups, leading to a complete picture of the spin density distribution of the triplet state in the tetrapyrrole macrocycle. The triplet-state properties of Chl b are found to be similar, in many respects, to those previously reported for Chl a, although some specificities have been highlighted. Concerning the spin density distribution, the differences are mainly localized on the carbon atoms close to the formyl group which, in Chl b, replaces the methyl group of Chl a.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2019-09-10 |