Contrasting Intrastrand Photoinduced Processes in Macromolecules Containing Pendant -Re(CO) 3 (1,10-phenanthroline + :Electron versus Energy Transfer

The photochemical and photophysical properties of the polymers {(vpy-CH 3 +) 2 -vpyRe(CO) 3 (phen) + } 2 0 0 (vpy = vinyl pyridine, phen = 1,10-phenanthroline) have been investigated in solution phase and compared to those ofa related polymer, {(vpy)2-vpyRe(CO) 3 (phen) + } 2 0 0 , and monomer, pyRe(CO) 3 (phen) + . Irradiations at 350 nm induce intrastrand charge separation in the peralkylated polymer, a process that stands in contrast with the energy migration observed with {(vpy) 2 -vpyRe(CO) 3 (phen) + } 2 0 0 . Electronically excited -vpyRe(CO) 3 (phen) + chromophores and charge-separated intermediates react with neutral species, e.g., 2,2',2"-nitrilotriethanol, and anionic electron donors, e.g., SO 3 2- and I - . The anionic electron donors react more efficiently with the metal-to-ligand charge transfer excited state of these polyelectrolytes than with the excited state of pyRe(CO) 3 (phen) + .