Synthesis and X-Ray Crystal Structures of Trinuclear Nickel(II) Complexes Derived from Schiff Bases and Acetate Ligands with Biological Activity.

The reactions of Ni(OAc)2 2H2O with Schiff base ligands 5-bromo-2-((cyclopentylimino)methyl)phenol (HL1) and 5-bromo-2-(((2-(isopropylamino)ethyl)imino)methyl)phenol (HL2) in methanol afforded two discrete trinuclear com-plexes [Ni3(L1)2(?2-?1:?1-OAc)2(DMF)2(BrSal)2] (1) and [Ni3(L2)2(?2-?1:?1-OAc)2(?2-?2:?1-OAc)2] (2), where BrSal is the monoanionic form of 4-bromosalicylaldehyde. The complexes were characterized by elemental analysis, IR and UV-Vis spectroscopy. The crystal structures of the complexes have been determined by X-ray crystallography. In both com-plexes, the nickel atoms are in octahedral coordination geometries. The L1 ligand coordinates to the nickel atoms through the phenolate O and imino N atoms, and the L2 ligand coordinates to the nickel atoms through the phenolate O, imino N and amino N atoms. The antimicrobial activities of the complexes were assayed.

[Preparation of Au Nanoparticles with Different Morphologies and Study of Their Property as Surface Enhanced Raman Scattering Substrates].

Different shapes of gold nanoparticles (NPs) have different enhancement effect in Surface Enhanced Raman Scattering (SERS). The polyhedral Au NPs have multiple angular structures, which show stronger enhancement effect than Au nanoplatelets. In recent years, the research on synthesis and properties of polyhedral Au NPs has attracted much attention. In this study the enhancement effect of the Au NPs in SERS was observed in Au NPs with the shape of dodecahedron, icosahedron, triangular plate and spherosome. Triangular Au NP films were prepared through a chemical reduction method using sodium borohydride as the reductant. As for synthesizing icosahedral Au NPs, Poly (vinyl pyrrolidone) is used as a capping agent and diethylene glycol is used as a reducing agent. Dodecahedral Au NPs were synthesized using icosahedral Au NPs as seeds. SERS spectra were detected for these three Au NPs as well as the traditional colloidal Au by using 4-mercaptopyridine and 4-mercaptobenzoic as probing molecules. Triangular Au NP films, icosahedral Au NPs and dodecahedral Au NPs were with average diameters of about 130, 100 and 120 nm. UV/Vis spectroscopy indicated that these three Au NPs had typical absorbance bands at 589, 598 and 544 nm. The results show that the Au polyhedron has better enhancement ability than the Triangular NPs.