Photoelectrochemical spill manipulation of N-arylviologen conjugated molecules

N-arylviologen conjugated molecules, 4,6-bis(1'-methyl-4,4'-bipyridine-1-yl )-pyrimidin (1) and 3,6-bis(1'-methyl-4,4'-bipyridine-1-yl)-pyridazine (2) were designed and synthesized. Electrochemical, spectroscopic, and magnetic properties of such molecules were investigated. Their multi-step reduction processes involving ion-radicals generation were observed in both electroc hemical and photochemical conditions. An attached electron in one electron reduced state, 2(3+), was more delocalized over the whole molecule than the case of 1(3+). The two electron reduced species, 1(2+), showed the ground state triplet biradical character, while 2(2+) had the quinoid-type closed shell structure. These features of electronic structure result from the nat ures of the heteroaromatic pi-conjugated linkers used here.