Synthesis and Characterization of 2-Iodo-4-[5′-(4'″-Methylpiperazin-1'″-yl)-2′,5′-bi-1h-Benzimidazol-2 ′-Yl]Phenol (iodoHoechst 33258) and 2,5-Disubstituted Benzimidazole Model Compounds