Syntheses, structures, and photoluminescent properties of four d10 metal-quinolinato coordination polymers with similar rod-like SBUs

Four MII quinolinato complexes, [Zn2(quin)2(H2O)3]n (1), [Zn(quin)(H2O)2]n (2), [Zn(quin)(H2O)]n (3) and [Cd(quin)]n (4) (H2quin = 2,3-pyridinedicarboxylic acid or quinolinic acid), have been hydrothermally synthesized and structurally characterized. X-ray diffraction analyses reveal that all of these four complexes are constructed from similar rod-like SBUs, [M(quin)]n (M = Zn or Cd). Complexes 1 and 2 have similar 1-D box-like chains but different packing structures; complex 3 has a 2-D grid-like network and complex 4 has an unusual 2-D bilayer structure. Due to the different structural features, these complexes exhibit different photoluminescent emissions: complex 1 at 439 nm (λex = 345 nm), complex 2 at 428 nm (λex = 360 nm), complex 3 at 508 nm (λex = 304 nm) and complex 4 at 500 nm (λex = 324 nm).