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

Abstract

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=360nm, 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.