Wei Luo

Synthesis, spectra and X-ray crystal structure of a new type of macrocyclic hexanuclear iron(III) cluster

A macrocyclic iron(III) 18-azametallacrown-6 compound, [Fe6(5-Brashz)6(H2O)6]u2009·u200920H2O(5-Brashzu2009=u2009N-acetyl-(5-bromosalicylhydrazide)), where the pentadentate ligands bridge the metal ions, was synthesized and characterized. Due to the meridional coordination of the ligand to the metal ion, the ligand is not only bridging the ring metal ions using a hydrazide N–N group, but also enforcing the stereochemistry of the metal ions as a propeller shape with alternating Λ/Δ configuration. The disc-shaped hexanuclear cluster is about 14.5u2009Å in diameter, 16.8u2009Å in thickness and has a vacant cavity in the center of the cluster.

Bent and linear trinuclear nickel complexes with ligands derived from N -acylsalicylhydrazide ligands: structural characterization and bioactivity

Two trinuclear Ni(II) complexes Ni3(L1)2(py)2(DMF)(H2O) (1) and Ni3(L2)2(py)2(DMF)2 (2) with two new trianionic pentadentate ligands N-(3,5-dimethylbenzoyl)-salicylhydrazide (H3L1) and N-(phenylacetyl)-5-nitrosalicylhydrazide (H3L2) have been synthesized and characterized by X-ray crystallography. Nickel ions in the two complexes have square-planar/octahedral/square-planar coordination. Central metal ion and two terminal metal ions in the two complexes are combined by two bridging deprotonated ligands, forming a trinuclear structural unit with an M–N–N–M–N–N–M core. Studies on the trinuclear Ni(II) complexes show that the β-branched N-acylsalicylhydrazide ligands with sterically flexible Cα methylene groups yield linear trinuclear Ni(II) complexes, while α-branched N-acylsalicylhydrazide ligands tend to form bent trinuclear Ni(II) complexes. Antibacterial screening data in a previous study indicates that bent trinuclear Ni(II) compound 1 is more active than linear compound 2 and less active than a tetranuclear nickel compound.

Bis(salicylhydrazide-κ2N,O)sulfatozinc(II) monohydrate

The title complex, [Zn(SO4)(C7H8N2O2)2]·H2O, contains neutral molxadecules of a mononuclear ZnII complex, in which the salicylhydrazide ligand is N,O-chelated to the ZnII ion. The ZnII ion is coordinated, in a tetragonal–pyramidal environment, by two O atoms and two N atoms from two salicylhydrazide ligands forming a basal plane, and one O atom from the sulfate anion occupying the apical position. The water molxadecule is disordered over two positions; the site occupancy factors are ca 0.6 and 0.4.