Syntheses, spectroscopic properties and X-ray crystal structures of tris(tfacacmetacyclophane)(bpy)europium(III) and piperidinium tetrakis(p-tolutfacac)europate(III) complexes

1-Trifluoromethyl-3-[2.2]metacyclophanyl-1,3-propanedione (HtfacacMCP) whic h has a non-planar conjugated pi system and 1-trifluoromethyl-3-(p-tolyl)-1 ,3-propanedione (p-tolutfacacH) as the referential ligand were prepared. Co mplexation of these ligands with europium(III) chloride in the presence of bipyridine (bpy) gave (tfacacMCP)(3)(bpy)Eu(III) and piperidinium[(p-tolutf acac)(4)Eu(III)] complexes respectively. The X-ray crystal structure of (tf acacMCP)(3)(bpy)Eu(III) revealed an eight-coordinate configuration with two N atoms of bpy and six O atoms of HtfacacMCP. On the other hand, piperidin ium [ (p-tolutfacac)(4)Eu(III)] was found to be an eight-coordinate complex surrounded by eight O atoms of p-tolutfacacH. The former contains bpy, but the latter contains no bpy. (C) 2000 Elsevier Science Ltd All rights reser ved.