The influence of the hydrogen bond network on the processes of energy migration between porphyrin molecules of the bacterial reaction centers (RC), charge separation and electron transfer to the quinone acceptor were investigated. Isotope substitution of H₂O by D₂O as well introduction of cryoprotectants force out the water from the structure of RC complexes were used for the influence on the hydrogen bonds network. Additionally, a structural isomer of RC samples without H-subunit modified by means of treatments mentioned above were used in the experiments. Effects of cryoprotectants on the redox properties of photoactive pigment were investigated too.

It was shown that in the excited state of porphyrin molecules, charge-transfer states or after radical forms of pigments appearing very fast solvation process (100-200 fs) take place. This solvation process is connected with repolarization of O-H and N-H hydrogen bonds. As a result a part of electronic energy (~0.05 eV) is dissipated in the initial steps of energy and electron transfer.

The temperature dependence of the rate constants of the ion-radical pair formation and their decay were studied in control and modified preparations. It was shown that the observed temperature dependence of the electron transfer rate constants is mainly related to the conformational and vibration states of the protein matrix. The vibrational states of the reaction centers were separated on high frequency sceleton vibrations of porphyrin molecules and low frequency vibrations (soft modes) of water-protein matrix. It is low frequency vibrations of water-protein matrix wich are mainly responsible for the observed temperature effects. Thus, water-protein surrounding of electron cofactors is an active participant in the photosynthetic primary processes.