Topological insights in polynuclear Ni/Na coordination clusters derived from a schiff base ligand

This article presents the syntheses, crystal structures, topological features and magnetic properties of two NiII/NaI coordination clusters (CCs) formulated [NiII3Na(L1)3(HL1 (MeOH)2] (1) and [NiII6Na(L1)5(CO3)(MeO (MeOH)3(H2O)3]·4(MeOH) 2(H2O) [2 4(MeOH) 2(H2O)] where H2L1 is the semi rigid Schiff base ligand (E)-2-(2-hydroxy-3 methoxybenzylideneamino)-phenol). Compound 1 possesses a rare NiII3NaI cubane (3M4-1) topology and compound 2 is the first example in polynuclear Ni/Na chemistry that exhibits a 2,3,4M7-1 topology

Copper(II) inverse-[9-metallacrown-3] compounds accommodating nitrato or diclofenac ligands: Structure, magnetism, and biological activity

Interaction of Cu(NO3)2 with phenyl 2-pyridyl ketoxime (PhPyCNOH) in the presence or absence of sodium diclofenac (Nadicl) leads to the formation of mono- or double-decker trinuclear clusters, respectively, characterized as inverse-9-metallacrown-3 accommodating dicl- or NO3- anions. The structures of [Cu3(PhPyCNO)3(μ3-O)(NO3)]2 (1) and [Cu3(PhPyCNO)3(μ3-OH)(dicl)2]·MeOH·0.5H2O (2·MeOH·0.5H2O) were determined by X-ray crystallography. Magnetic studies show a large antiferromagnetic interaction, whereas a discrepancy appears between the low-temperature magnetic data and that predicted from an isotropic Hamiltonian model, indicating the influence of antisymmetric interactions. By using a different magnetic model with antisymmetric terms, the low-temperature susceptibility and magnetization data were fitted. The EPR data support the observation that 2 has isosceles or lower magnetic symmetry, whereas the antisymmetric exchange mechanism is used to identify the reported g values of the spectra. EPR studies also revealed that complex 2 keeps its structure in solution. The complexes interact with calf-thymus DNA by intercalation. The complexes, as well as [Cu2(dicl)4(H2O)2] (3), bind to albumins with relatively high binding constants. The highest cytotoxicity of the diclofenac compounds was observed after 24 h of incubation, whereas HL-60 cells recovered after 72 h of incubation in the presence of each compound. Moreover, complex 3 was the most cytotoxic among the compounds, and complex 2 was as cytotoxic as Nadicl. Mono- and double-decker inverse-9-metallacrown-3 CuII compounds constructed with phenyl 2-pyridyl ketoxime ligands accommodating diclofenac or nitrato ligands, respectively, have been structurally characterized and their biological behavior has been evaluated in vitro. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim