Schiff Base Ancillary Ligands in Bis(diimine) Copper(I) Dye-Sensitized Solar Cells.

Five 6,6'-dimethyl-2,2'-bipyridine ligands bearing -arylmethaniminyl substituents in the 4- and 4'-positions were prepared by Schiff base condensation in which the aryl group is Ph (), 4-tolyl (), 4-BuCH (), 4-MeOCH (), and 4-MeNCH (). The homoleptic copper(I) complexes [CuL][PF] (L = -) were synthesized and characterized, and the single crystal structure of [Cu()][PF]EtO was determined. By using the "surfaces-as-ligands, surfaces-as-complexes" (SALSAC) approach, the heteroleptic complexes [Cu()(L)] in which is the anchoring ligand ((6,6'-dimethyl-[2,2'-bipyridine]-4,4'-diyl)bis(4,1-phenylene))bis(phosphonic acid)) and L = - were assembled on FTO-TiO electrodes and incorporated as dyes into n-type dye-sensitized solar cells (DSCs).