Abstract
Electron nuclear double resonance signals of the pyrrole N of bacteriochlorophyll a cation [from Rhodospirillum rubrum] in a solution of CH2Cl2/CH3OH (6:1) were observed. The N are inequivalent: the hyperfine coupling constants were 2.36 and 3.18 MHz (0.84 and 1.14 G, respectively). Triple electron nuclear double resonance experiments have yielded the signs and values of 9 proton hyperfine coupling constants. The assignment based on these data agrees well with previous work; 2 methine protons were also identified. Spin densities calculated from the hyperfine couplings are compared to reported molecular orbital calculations.

This publication has 17 references indexed in Scilit: