Crystal structures of transition metal complexes with an asymmetrical tridentate Schiff-base ligand

Synthesis, crystal structures, and luminescent properties of Zn(ii), Cd(ii), Eu(iii) complexes and detection of Fe(iii) ions based on a diacylhydrazone Schiff base

“…A variety of transition metals complexes based on them have indicated that this kind of ligands possessed the advantage of constructing different forms of structures. [22][23][24][25] To extend our research, we designed and synthesized a new diacylhydrazone Schiff base (N 01 E,N 04 E)-N 01 ,N 04 -bis(2-hydroxy-5-nitrobenzylidene)succinohydrazide (H 4 L) (Scheme 1) by the condensation of nitrosalicylaldehyde and succinic dihydrazide. Even more importantly, we got three novel binuclear complexes Zn-L, Cd-L, Eu-L, and studied the structures and optical properties of them.…”

Influence of Semirigidity and Diverse Binding Modes of an Asymmetric Pyridine-pyrazole Based Bis-Chelating Ligand in Controlling Molecular Architectures and Their Properties

“…Notwithstanding, barring a few random examples, most of these ligands are flexible and symmetrically linked with two similar chelating functional groups of well-defined coordinating behavior. , In a stark contrast, we have recently demonstrated the usefulness of semirigid pyridyl-pyrazole based asymmetric bis-bidentate ligands in developing a wide range of transition as well as lanthanide metal-directed cage and clusters with aesthetically pleasing structures and fascinating magnetic properties. , Of particular relevance to this work is the unique cause and effect relationship that exists between structural asymmetry and magnetism for a series of lanthanide cages. It has been observed that the origin of the magnetic properties including single-molecule magnets (SMMs) behavior has a strong link to the dissimilar coordination environments adopted by the metal centers within a cage structure. − This, in turn, was attributed to unique combined features of our ligand systems, two asymmetric coordination compartments, semirigid conformations, and coordination flexibility of the functional groups present. It is noteworthy here that magnetic interactions, especially magnetic relaxation rates for SMMs, have a strong link to the coordination geometry of the paramagnetic metals centers, and even tiny distortions have a profound effect on the overall magnetic outcome. − …”

Synthesis, crystal structures and luminescent properties of tetranuclear Zn molecular clusters with aroylhydrazone ligand

“…9 We have designed and synthesized an aroylhydrazone Schiff base ligand. 10 A preliminary study of its transition metal complexes and a few related literature reports 11 have indicated that this kind of ligand possesses the advantage of constructing polynuclear complexes. To extend our research, another aroylhydrazone Schiff base ligand, (E)-N9-(2,3-dihydroxybenzylidene)-4hydroxybenzohydrazide (H 3 L), was designed and synthesized (Scheme 1).…”

“…To extend our research, another aroylhydrazone Schiff base ligand, (E)-N9-(2,3-dihydroxybenzylidene)-4hydroxybenzohydrazide (H 3 L), was designed and synthesized (Scheme 1). On comparison with the ligand in our previous work, 10 an additional hydroxyl group was introduced at the 3-position of the benzylidene part, which provided suitable, disposable bridging groups to control the stereochemistry of the metallic centres as well as the number of metal ions within the cluster motifs. Two kinds of tetranuclear Zn(II) molecular clusters have been constructed by this ligand successfully.…”