Lanthanide complexes with 8-quinolinyloxyacetate (qoa): Synthesis and supramolecular assembly by hydrogen bonds

Two new lanthanide supramolecular complexes, [Tb(qoa)2(H2O)2]⋅NO3 ⋅ H2O (1) and [Er(qoa)3] ⋅ 2H2O (2) [qoa = (8-quinolinyloxy)acetate] were obtained by treating the corresponding nitrates and (8-quinolinyloxy)acetic acid (Hqoa) under hydrothermal conditions. Complex 1 possesses a 1D zigzag chain bridged by the qoa anions, which is further connected to form a 3D supramolecular framework via hydrogen bonds and π–π attractions. Compound 2 is a mononuclear structure and the coordination units are further assembled to a 1D helical chain parallel to the b-axis via hydrogen bonds. Obviously, various coordination modes of the qoa anions and the intermolecular attractions have effect on the formations of two complexes. The solid-state luminescent behavior of 1 has been investigated at room temperature.