Donor-Acceptor Porphyrin Systems with Persistent Charge Separation

摘要

Two types of donor–acceptor porphyrin systems with very long lifetimes of charge separation (tens, hundreds of hours and more) are considered. Systems of the first type are based upon the reaction of electron photodetachment from porphyrin anions at 77 K. In this case an electron can be removed from the anion by up to 1000 A. Systems of the second type are the complexes of some metalloporhyrins (Zn-, Cd-porphyrins) (I) with disodiumpyridine (II), where the photoinduced electron transfer from II to I takes place at 77 K. The reverse process does not occur in darkness. For this system, the equilibrium geometry corresponding to the state with separated charges considerably differs from that of the ground state. For this new geometry, the state with separated charges is the ground one.