Triplet excited state energies and phosphorescence spectra of (bacterio)chlorophylls

(Bacterio)Chlorophyll ((B)Chl) molecules play a major role in photosynthetic light-harvesting proteins, and the knowledge of their triplet state energies is essential to understand the mechanisms of photodamage and photoprotection, as the triplet excitation energy of (B)Chl molecules can readily generate highly reactive singlet oxygen. The triplet state energies of 10 natural chlorophyll (Chl a, b, c2, d) and bacteriochlorophyll (BChl a, b, c, d, e, g) molecules and one bacteriopheophytin (BPheo g) have been directly determined via their phosphorescence spectra. Phosphorescence of four molecules (Chl c2, BChl e and g, BPheo g) was characterized for the first time. Additionally, the relative phosphorescence to fluorescence quantum yield for each molecule was determined. The measurements were performed at 77K using solvents providing a six-coordinate environment of the Mg(2+) ion, which allows direct comparison of these (B)Chls. Density functional calculations of the triplet state energies show good correlation with the experimentally determined energies. The correlation determined computationally was used to predict the triplet energies of three additional (B)Chl molecules: Chl c1, Chl f, and BChl f.

Medienart:

E-Artikel

Erscheinungsjahr:

2014

Erschienen:

2014

Enthalten in:

Zur Gesamtaufnahme - volume:118

Enthalten in:

The journal of physical chemistry. B - 118(2014), 26 vom: 03. Juli, Seite 7221-32

Sprache:

Englisch

Beteiligte Personen:

Hartzler, Daniel A [VerfasserIn]
Niedzwiedzki, Dariusz M [VerfasserIn]
Bryant, Donald A [VerfasserIn]
Blankenship, Robert E [VerfasserIn]
Pushkar, Yulia [VerfasserIn]
Savikhin, Sergei [VerfasserIn]

Links:

Volltext

Themen:

17778-80-2
2683-84-3
Bacteriochlorin
Bacteriochlorophylls
Chlorin
Journal Article
Porphyrins
Research Support, U.S. Gov't, Non-P.H.S.
Singlet Oxygen

Anmerkungen:

Date Completed 29.05.2015

Date Revised 18.09.2014

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1021/jp500539w

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM238871096