Tetranuclear Zn(II) and Mononuclear Nickel(II) Complexes Based on Asymmetric Salamo-Type Ligands: Syntheses, Crystal Structures, and Fluorescent Properties

Two new complexes [{Zn(L1)(μ-OAc)Zn(CH3CHOHCH3)}2] and [Ni(L2)(H2O)(CH3OH)] with asymmetric Salamo-type ligands (H3L1 and H2L2) are synthesized and structurally characterized. In the Zn(II) and Ni(II) complexes, the terminal and central Zn(II) atoms are found to have slightly distorted square pyramidal and trigonal bipyramidal symmetries respectively, while the Ni(II) atom is hexa-coordinated and has a slightly distorted octahedral symmetry. Interestingly, a self-assembling continual zigzag 1D chain is formed by intermolecular hydrogen bonds in the Ni(II) complex. Furthermore, the Zn(II) and Ni(II) complexes in the ethanol solution show intense photoluminescence.