title: Lessons from chlorophylls: modifications of porphyrinoids towards optimized solar energy conversion.
abstract: Practical applications of photosynthesis-inspired processes depend on a thorough understanding of the structures and physiochemical features of pigment molecules such as chlorophylls and bacteriochlorophylls. Consequently, the major structural features of these pigments have been systematically examined as to how they influence the S1 state energy, lifetimes, quantum yields, and pigment photostability. In particular, the effects of the macrocyclic π-electron system, central metal ion (CMI), peripheral substituents, and pigment aggregation, on these critical parameters are discussed. The results obtained confirm that the π-electron system of the chromophore has the greatest influence on the light energy conversion capacity of porphyrinoids. Its modifications lead to changes in molecular symmetry, which determine the energy levels of frontier orbitals and hence affect the S1 state properties. In the case of bacteriochlorophylls aggregation can also strongly decrease the S1 energy. The CMI may be considered as another influential structural feature which only moderately influences the ground-state properties of bacteriochlorophylls but strongly affects the singlet excited-state. An introduction of CMIs heavier than Mg2+ significantly improves pigments' photostabilities, however, at the expense of S1 state lifetime. Modifications of the peripheral substituents may also influence the S1 energy, and pigments' redox potentials, which in turn influence their photostability.
authors.affiliation: Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland. dariusz.karcz@uj.edu.pl.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Karcz
authors.affiliation: Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland. alicja.ratuszna@us.edu.pl.
authors.forename: Bożena
authors.initials: B
authors.lastname: Boroń
authors.affiliation: Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland. arkadiusz.matwijczuk@up.lublin.pl.
authors.forename: Arkadiusz
authors.initials: A
authors.lastname: Matwijczuk
authors.affiliation: Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland. justyna.furso@gmail.com.
authors.forename: Justyna
authors.initials: J
authors.lastname: Furso
authors.affiliation: Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland. jakubstaron@gmail.com.
authors.forename: Jakub
authors.initials: J
authors.lastname: Staroń
authors.affiliation: Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland. alicja.ratuszna@us.edu.pl.
authors.forename: Alicja
authors.initials: A
authors.lastname: Ratuszna
authors.affiliation: Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland. leszek.fiedor@uj.edu.pl.
authors.forename: Leszek
authors.initials: L
authors.lastname: Fiedor
mesh_terms: D002734:Chlorophyll / Q000737:chemistry*; D015394:Molecular Structure; D010788:Photosynthesis; D012993:Solar Energy
chemical_list: D002734:Chlorophyll