Crystal structures of the lanthanum(III), europium(III), and terbium(III) cryptates of tris(bipyridine) macrobicyclic ligands

The crystal structures of I.LaCl3.2H2O and I.TbCl3.4H2O (X = H) and I.EuCl3.4H2O (X = COOCH3) were detd. I.LaCl3.2H2O is triclinic, space group P?1, with a 18.602(5), b 17.342(5), c 14.130(5) Å, ? 99.98(2), ? 106.26(4), and ? 103.2(3)°; R = 5.8% (Rw = 5.6%). I.TbCl3.4H2O is orthorhombic, space group Cmca, with a 25.510(8), b 10.279(4), and c 31.021(9) Å; R = 5.0% (Rw = 7.3%). I.EuCl3.4H2O is monoclinic, space group C2/c, with a 30.715(8), b 14.121(5), c 23.813(8) Å, and ? 118.62(4)°; R = 5.9% (Rw = 6.2%). The structures confirm the cryptate nature of these species, the cations being bound to the 8 N sites of the ligand. The macrobicycle presents 2 open faces, thus allowing addnl. coordination of 2 species, Cl- ions or H2O mols., to the bound cations. These data provide structural support for the photophys. studies of the luminescent properties of the EuIII and TbIII cryptates, which indicated residual coordination of H2O mols. [on SciFinder(R)]