Design, Synthesis, Characterization, and Crystal Structures of 2-Pyridyl Naphthyl Selenides

A convenient method for the preparation of several unsymmetrical 2-pyridy1/4-aryl 1-naphthyl selenides is presented. The newly prepared compounds have been obtained in good yields by the reaction of substituted 2, 2'-dipyridyl diselenides with 1-bromo naphthalene or vice-versa using cuprous oxide-bipyridyl catalyst employing magnesium as reductant in dimethyl formamide. A combination of both the copper catalyst and magnesium proved ideal to afford the title compounds in good results. The newly synthesized 2-pyridy1/4-aryl 1-naphthyl selenides are either viscous liquids or crystalline solids that are stable at room temperature for several months without decomposition. The compounds were fully characterized by various spectroscopic techniques, namely, NMR (H-1, C-13, Se-77), IR, and mass spectroscopy. Single crystal X-ray diffraction study was carried out on four molecules to know unambiguously their structural details. Well-defined diffraction quality crystals were obtained by dissolving the compounds in dichloromethane and then layering with hexane followed by slow evaporation.