3-D Hydrogen-bonded networks of metal complexes with chelidamic acid and 1,10-phenanthroline: syntheses, structures, and optical properties

The title complexes, (C(12)H(8)N(2)) [La(C(7)H(3)NO(5))(C(7)H(4)NO(5))center dot 3H(2)O] 1.75H(2)O (1), (C(12)H(8)N(2)) [Pr(C(7)H(3)NO(5))(C(7)H(4)NO(5))center dot 3H(2)O]center dot 2H(2)O (2), (C(12)H(8)N(2))[Nd(C(7)H(3)NO(5))(C(7)H(4)NO(5))center dot 3H(2)O]center dot 2.25H(2)O (3), and (C(12)H(8)N(2)) [Fe(C(7)H(3)NO(5))(C(7)H(4)NO(5))]center dot 2H(2)O (4), were synthesized and characterized by single-crystal X-ray diffraction. The crystal structures of 1-3 reveal that they are isomorphous, among which the metal atoms are all nine-coordinate with distorted tricapped trigonal prismatic coordination geometries. The Fe is six-coordinate with a distorted octahedron by two chelidamic acid ligands in 4. Complexes 1-4 are formed into 3-D networks by H-bonds and - stacking interactions. The fluorescence spectra of 1-3 were investigated and all exhibit strong luminescence.