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We describe herein the synthesis, crystal structure and ¹H NMR properties of the mononuclear [ZnII(L-Br)].2H2O complex containing the hexadentate H2L-Br ligand (H2L-Br = N,N'-bis-(5-bromo-2-hydroxybenzyl)-N,N '-bis-(pyridin-2-ylmethyl)-ethane-1,2-diamine). DFT calculations demonstrate very good agreement between parameters calculated and those determined by X-ray crystallography, and reveal that only the phenolate groups of the H2L-Br ligand participate in the formation of the HOMO, while only one of the pyridine rings contributes to the LUMO formation.

Three new iron(III) complexes with the ligand N,N'-bis(2-hydroxybenzyl)-N-N'-bis(pyridine-2-ylmethyl)ethylenediamine, H9sub 2)bbpen, containing electron-donating and withdrawing groups (me, Br, NO(sub 2) in the 5-position of phenol rings were synthesized and characterized. The redox potentials Fe(super III)/Fe(super II) and the energies of the charge transfer process of these complexes were found to be linearly correlated with the Hammett parameter.

Two heterometallic photocatalysts were designed and probed for water reduction. Both [(bpy)2RuIINiII(L1)](ClO4)2 (1) and [(bpy)2RuIINiII(L2)2RuII(bpy)2](ClO4)2 (2) can generate the low‐valent precursor involved in hydride formation prior to dihydrogen generation. However, while the bimetallic [RuIINiII] (1) requires the presence of an external photosensitizer to trigger catalytic activity, the trimetallic [RuIINiIIRuII] (2) displays significant coupling between the catalytic and light‐harvesting units to promote intramolecular multielectron transfer and perform photocatalysis at the Ni center. A concerted experimental and theoretical effort proposes mechanisms to explain why 1 is unable to achieve self‐supported catalysis, while 2 is fully photocatalytic. [ABSTRACT FROM AUTHOR]

Research has been conducted on the heterodinuclear Fe (super)III Zn (super)II complex. The synthesis of this complex has been carried out and its characterization via the use of X-ray crystallography has demonstrated that the complex cation has Fe (super)III Zn (super)II (mu-phenoxo)-bis(mu-carboxylato) core.

Research has been conducted on the heterodinuclear mixed valence Fe (super)III Mn (super)II complex with the unsymmetrical N (sub)5 O (sub)2 donor ligand. The synthesis and characterization of this complex have been carried out and the results are discussed.

4‐Chloro‐N‐(pyridin‐2‐ylmethyl)aniline (CPYA) was synthesized by a simple and inexpensive method and tested as a corrosion inhibitor in acid medium for mild steel by using gravimetric studies and electrochemical measurements. An average maximum efficiency of 96.0% was achieved at 4.59 mmol/L. Corrosion kinetic and thermodynamic parameters were also analyzed. Surface analyses (atomic force microscopy and scanning electron microscopy) show that protection is enabled by adsorption on the metal, forming a film. Quantum chemical calculations were performed to access information regarding the molecular structure in the corrosive medium and to support interpretation of the results obtained by experimental methods. [ABSTRACT FROM AUTHOR]

The design of new molecular scaffolds for multispin complexes based on a novel binucleating ligand, where the coordinated metals exhibit unusual geometries that stabilize radical formation, is described. Well-behaved one-electron oxidations and reductions are needed for precise modulation and switching and might lead to the use of different metal centers and organic groups capable of radical stabilization.

Monometallic species with d(super 5) high-spin iron and d(super 10) gallium were synthesized and studied to assess the influence of the ligand rigidity and the presence of tertiary butyl substituted phenol rings on their steric, electronic and redox behavior. The results showed that the nature/rigidity of the ligand defines whether meridonal or facial coordination would take place.

This paper describes the synthesis, and electronic and redox properties of three nickel(II) and two copper(II) complexes, namely, [Ni(L1)(Cl)2]·2H2O (1), [Ni(L2)(Cl)2]·H2O (2), [Cu(L2)(ClO4)]ClO4 (3), [Ni(L3)(Cl)2]·H2O (4), and [Cu(L3)(ClO4)]ClO4·2H2O (5). Ligands L1, L2 and L3 each contain a 1,2-bis((pyridine-2-ylmethyl)-azaneyl)ethane framework decorated with electron donating methyl and methyl/methoxy substituents. We observe a correlation between the electron donating capability of the ligands (L1 < L2 < L3) and the redox potential for the MII/MI couple (1 > 2 > 4 and 3 > 5). After thorough identification of the spectroscopic and redox properties of 1–5, the reactivity of the complexes was investigated towards proton and water reduction by means of electro and photocatalysis. These species seemingly support H2 evolution and display tunable catalytic properties achieved through the presence of differentiated electron donicity. Evidence of degradation with nanoparticle conversion was found to depend on the nature of both ancillary ligand and metal center. [ABSTRACT FROM AUTHOR]

The X-ray structure, solution studies, and phosphatase activity of the first mixed-valence complex containing the [Fe.sup.III]([mu]-OH)[Zn.sup.II] motif is reported.