Preparation, characterization and bifunctional electrocatalysis of an inorganic–organic complex with a vanadium-substituted polyoxometalate

On the preferences of five-membered chelate rings in coordination chemistry: insights from the Cambridge Structural Database and theoretical calculations

The purpose of this review is to give an overview of three important N-bidentate ligands: 1,10-phenanthroline (phen), 2,2'-bipyridine (bpy), and ethylenediamine (en). We have not attempted to be comprehensive because of the huge amount of activity being done in coordination chemistry using these ligands. Instead we present a full structural and geometrical study by using the Cambridge Structural Database (CSD) combined with theoretical calculations that allow us to parameterize their coordinating properties and ability to coordinate to transition and non-transition metals. More importantly, we illustrate that upon coordination and formation of the five-membered chelate ring, these ligands are able to adapt themselves to the requirements of the different metals by changing the MN distances and NMN angles. Therefore, a redefinition of the preferences of these ligands to metals with large ionic radii is needed. Finally, we will present some facts about the participation of these ligands in inorganic-organic hybrids (IOHs) based on Keggin polyoxometalates (POMs).

Heterogenization of heteropoly compounds: a review of their structure and synthesis

The heterogenization of different types of heteropoly compoundsviasix popular methods from those published over the past recent 15 years is reviewed.

A light-harvesting polyoxometalate-polypyridine hybrid induces electron transfer as its Re(I) complex

A derivative of the Dawson polyoxometalate [P2V3W15O62](9-) functionalized with one remote bipyridine coordination site (2) has been synthesized and combined with the neutral {Re(CO)3Br} moiety. The new Re(I)-hybrid (3) was characterized by various analytical techniques. Hybrid 3 exhibits several redox processes on a wide range of potentials with reductions centered on V(V), W(VI) and the organic ligand in order of decreasing potential. Both units, the polyoxometalate and the transition metal complex, retain their intrinsic properties in the hybrid 3, which displays photosensitization in the UV region with tailing into high-energy visible region.

Bis[tris-(phenanthroline-κ(2) N,N')cobalt(II)] undeca-tungsto(VI)vanado(V)phosphate dihydrate

In the title hydrated salt, [Co(C₁₂H₈N₂)₃]₂[PVW₁₁O₄₀]·2H₂O, the complete Kegggin ion is generated by crystallographic inversion symmetry, which imposes statistical disorder on the O atoms of its central PO₄ group. The V atom is statistically disordered over all the metal sites of the anion. In the cation, the Co²⁺ ion is coordinated by three bidentate 1,10-phenanthroline (phen) ligands, generating a distorted CoN₆ octa­hedron. Possible very weak intra­molecular C—H⋯π inter­actions occur in the cation. In the crystal, the components are linked by O—H⋯O and C—H⋯O inter­actions, building a three-dimensional network featuring one-dimensional voids along the c-axis direction.

An electrochemical sensing platform based on a new copper complex for the determination of hydrogen peroxide and nitrite

A new copper(II) complex [Cu(C12H23N3)4Br2·2H2O] was synthesized and its structure was characterized by x-ray crystallography and elemental analysis. The copper atom had a distorted octahedron coordination involving two bromide anions and four nitrogen atoms from the 1-decyl-1H-[1,2,4]triazole ligands. Moreover, the electrochemical behavior and electrocatalysis of the carbon paste electrode (Cu-CPE) bulk-modified by the complex have been studied in detail. The Cu-CPE showed excellent electrocatalytic activities toward the reduction of hydrogen peroxide and nitrite, and the detection limit was much lower than that mentioned in earlier reports. This bulk-modified CPE has good reproducibility, long-term stability and surface renewability, which appear promising for constructing chemical sensors.