Käß, H.; Rautter, J.; Zweygart, W.; Struck, A.; Scheer, Hugo; Lubitz, Wolfgang
EPR, ENDOR, and TRIPLE resonance studies of modified bacteriochlorophyll cation radicals.
In: Journal of Physical Chemistry, Vol. 98, No. 1: pp. 354-363
A series of substituted bacteriochlorophyll molecules, all used in reconstitution experiments of reaction centers of Rhodobacter sphaeroides (Struck et al. Biochim. Biophys. Acta 1991, 1060, 262-270), were characterized by EPR, electron-nuclear double (ENDOR), and electron-nuclear-nuclear triple (TRIPLE) resonance spectroscopy in their monomeric radical cation states. Effects of different substituents at position 3 in the porphyrin macrocycle were considered, especially for two «crosslinks» between plant and bacterial chlorophylls. These are 3-vinylbacteriochlorophyll where the «bacteria» acetyl group at position 3 was substituted by vinyl and 3-acetylchlorophyll where the «plant» vinyl group was substituted by acetyl