Synthesis and characterization of a novel Europium(III) complex with a one-dimensional chain-like structure

By means of a solvothermal reaction of isonicotinic acid and europium perchlorate, a novel europium(III) com- plex, i.e. catena- [tri(mu(2)-isonicotinato-O,O')-(biaqua-europium(III))-(triperchlorate)-(monohydrate)1, Mu(HIA)(3)(H2O)(2)](n)center dot 3n(ClO4)-nH(2)O (1; HIA = isonicotinic acid), was obtained. The molecular structure of complex 1 was characterized by single-crystal X-ray crystallography. Complex 1 crystallized in the space group P (1) over bar of the triclinic system with a = 9.5500(2), b = 10.9680(3), c = 15.1214(4) angstrom, a = 104.299(2)degrees, beta = 91.532(2)degrees, gamma = 111.310(2)degrees, V = 1417.92(6) angstrom(3), C18H21Cl3EuN3O21, M-r = 873.69, Z = 2, D-c = 2.046 g/cm(3), mu(MoK alpha) = 2.595 mm(-1) and F(000) = 864. The europium(III)) ions are coordinated by eight oxygen atoms (of which six come from six HIA ligands and two come from two water molecules) and displays a EuO8 square antiprismatic geometry. The adjacent europium(III) ions are interlinked by four or two mu(2)-bridging HIA ligands to generate an infinite onedimensional (1-D) -Eu-(HIA)(4)-Eu-(HIA)(2)-Eu-(HIA)(4)-Eu- chain running along the a axis. The chains are further connected by pi...pi stacking and hydrogen bonding interactions to yield a three-dimensional (3-D) su- pramolecular network. Complex 1 exhibits red photoluminescence emission bands at 593 nm, 617 nm and 699 nm, which are originated from the D-5(0) -> F-7(1), D-5(0) -> F-7(2) and D-5(0 )-> F-7(4) characteristic transitions of europium(III) ions. It has CIE chromaticity coordinates of (0.5742, 0.3275). A solid-state UV/Vis diffuse reflection spectrum shows that complex 1 has a band gap of 5.02 eV with a direct transition process.

Automated summary

A novel europium(III) complex, synthesized via a solvothermal reaction, exhibits a complex molecular structure with red photoluminescence emission properties. It has potential optical applications due to its unique characteristics.