Research On Syntheses,Structures And Properties Of Metal Complexes Based On Ketoxime Containing Pyridine Ring

Ketoxime ligands can form different types of complexes when they reacted withdifferent metal salts, among of which are metallacrowns, owing to strong coordinationability and multiform coordination. These complexes have potential application values incoordination chemistry, supramolecular chemistry, material and biological science due totheir special chemical properties, biological activities, as well as magnetic properties. Inour work, twenty-three complexes are synthesized through ketoxime [phenyl2-pyridylketoxime, methyl-2-pyridylketoxime and di-2-pyridyl-ketonoxime] ligands functioningwith different metal salts, and they were characterized by X-ray single crystal diffraction,FI-IR spectra and elemental analysis. In vitro cytotoxic activities, DNA binding andmagnetic properties of some complexes have been determined. The main contents arelisted as follows:1. Thirteen complexes were obtained by the reactions of phenyl-2-pyridylketoxime(ppkoH) the ligand with different metal salts:[Cu6(ppko)6(μ4-O)2(N(CN)2)](1),[Cu3(ppko)3(μ3-OH)(OAc)2)]·CH3OH·2H2O(2),[Cu3(ppko)3(μ3-OH)(OAc)2]·py(3),[Cu3(ppko)3(μ3-OH)(Cl)2](4),[Cu3(ppko)3(μ3-OH)(HCOO)2](5),[Cu3(ppko)3(μ3-OH)(PhCOO)2](6),[Cu2(ppko)4](7),[Cu2(ppko)2(ppkoH)2]·2N3(8),[Cu(ppko)2·py](9),[Zn4(ppko)4(PHCOO)2(OH)2]·2py(10),[Zn4(ppko)4(CH3COO)2(OH)2]·[Zn4(ppko)4(HCOO)2(CH3COO)2]·CH3OH(11),[Zn(ppko)2(PHCOO)2](12) and [Co5(ppko)3(O)Cl2(CH3O)6](13). Complexes1-6are inverse9-MC-3metallacrown, in which the repeatingunit is Cu-N-O. Complex1displays a off-set stacked inverse9-MC-3metallacrownlinked via two Cu-O bonds, and the molecules are connected into2D via C-H···Ninteractions. Complexes2-6are monolayer metallacrowns, containing a[9-MCCuII(N)ppko-3]3+. In complex2, molecules are connected into2D via O-H···Ointeractions. In complexes3and6, molecules are assembled into2D through C-H···Ointeractions. In complex4, molecules are connected into2D via C-H···Cl and O-H···Clinteractions. In complex5, molecules are self-assembled into2D through C-H···Ointeractions. Complexes7and8are a di-nuclear copper complexes. In complex7,molecules are connected into2D by C-H···O interactions. Complex9is a mononuclear Cu complex. Complex10and11are12-MC-4metallacrowns, and the repeating unit isZn-N-O. In complex10, molecules are connected into2D by C-H···O interactions.Complex12is a mononuclear zinc complex, the molecules are connected into a1D viathe C-H···π interactions. Complex13is a pentanuclear cobalt complex, the molecules areconnected into a2D via the C-H···O and C-H···Cl interactions. By using a standard MTTassay, the antitumor tests show that the complexes1,3-5and7-9possess a potentbroad-spectrum cytotoxicity, and complexes10and12do not dispaly in vitro antitumoractivity. The DNA binding properties of complexes1-9with calf thymus DNA(CT-DNA) have also been investigated by fluorescent spectra, and the result indicate thatstrong interactions exist between complexes1-9and CT-DNA. Magnetic measurementsof complex1,3,4,6and13indicate that these complexes are antiferromagnetic couplinginteractions.2. Seven complexes were obtained by the reactions of methyl-2-pyridylketoxime(mpkoH) with different metal salts:[Cu3(mpko)3(CH3COO)(OH)2](14),[Cu3(mpko)3(CH3COO)2(OH)]·py(15),[Cu3(mpko)3(CH3COO)2(OH)][Cu3(mpko)3(HCOO)2(OH)](16),[Cu9(O)3(mpko)9[N(CN)2]2]·[N(CN)2]·CH3OH(17),[Pr3Ni3(mpko)9(NO3)3(OH)3(O)2](18),[Ni(mpko)2·(py)2](19) and [Ni(mpko)(mpkoH)·N3·py](20). Complexes14-17are9-MC-3metallacrowns, in which each of the Cu ions is located in a distortedsquare-pyramid coordination environment and the repeating unit is Cu-N-O. Complexes14-16are monolayer metallacrowns. In complex14, molecules are connected into2D viaC-H···O and C-H···N interactions. In complex15, molecules are self-assembled into2Dthrough C-H···O interactions. Complex16contains two dependent9-MC-3metallacrownunits. Complex17consists of three off-set [CuII3O]5+triangles linked together via Cu-O.Complex18is a hexanuclear mixed metal complex. Complexes19and20aremononuclear nickel complex. In complex19, molecules are connected into2D viaC-H···O interactions. In complex20, molecules can form into2D through C-H···N andC-H···O interactions. By using a standard MTT assay, the antitumor tests show that thecomplexes14and17possess a potent broad-spectrum cytotoxicity and complexes19and20possess no in vitro antitumor activity. Magnetic measurements of complex14,17 and18indicated that these complexes are antiferromagnetic coupling interactions.3. Seven complexes were obtained by the reactions of di-2-pyridyl-ketonoxime(dpkoH) with different metal salts:[Ni4(dpko)3(OH)(CHCOO)(CH3COO)4(H2O)](21),[Cu2Er(dpko)4(OH)4]2·CH3OH(22) and [Cu(dpko)2·py](23). Complex21is a9-MC-3metallacrown with the fourth Ni atom arrested in the cavity of ring. Complex22is amixed metal complex. Complex23is a mononuclear copper complex and the moleculesare connected into a2D via C-H···O interactions. Magnetic measurements of complex21indicated that these complexes are antiferromagnetic coupling interactions.