lectron Spin-Lattice relaxation rates are reported for frozen solutions of the blue-copper proteins azurin and plastocyanin, the low-spin iron heme protein cytochrome-c, two (bis)imidazole ferric heme complexes in three different organic solvents and two ferricyanide solutions. Measurements were performed at X-band frequencies and temperatures between 1.4 and 22 K. Relaxation rates show a one-phonon direct process at low temperatures (T... |