Preparation and chemical properties of π-conjugated poly(1,10-phenanthroline-3,8-diyl)s with crown ether subunits

π-Conjugated polymers consisting of 1,10-phenanthroline units and crown ether subunits (Poly-1, Poly-2, and Poly-3) were prepared by dehalogenation polycondensation of the corresponding dibromo monomers using a zero-valent nickel complex as a condensing agent. They were characterized by elemental analysis, 1H NMR and UV-Vis spectroscopies, and cyclic voltammetry (CV). They were partly soluble in CHCl3, and the number average molecular weight of the soluble part of Poly-2, which had 15-crown-5 subunits, was estimated to be 5300. The polymers exhibited UV-Vis peaks at approximately λmax = 360 nm, which was reasonable. Complexation with [Ru(bpy)2]2+ and alkaline metal ions made the polymer soluble in organic solvents. The complexation of [Ru(bpy)2]2+ to the 1,10-phenanthroline unit proceeded quantitatively, and the [Ru(bpy)2]2+ complexes exhibited CV curves characteristic of [Ru(N-N)3]2+ complexes.