The ligand 2-anilino-4,6-di-tert-butylphenol and its 2-(3,5-dichloroanilino)-4,6-di-tert-butylphenol analogue react in CH(3)CN or CH(3)OH solutions with divalent transition metal ions the presence of air triethylamine. Depending on metal:ligand ratio (1:1, 1:2, 1:3) (or absence) cyclic amine 1,4-dimethyl-1,4,7-triazacyclononane (dmtacn), following complexes have been isolated as crystalline solids: [Co(III)(L(ISQ))(3)] (1); [Cu(II)(dmtacn)(L(ISQ))]PF(6) (2); [Cu(II)(L(ISQ))(2)] (3);...

The development of efficient water oxidation catalysts based on inexpensive and Earth-abundant materials is a prerequisite to enabling splitting as feasible source alternative energy. In this work, we report the synthesis ternary cobalt manganese phosphide nanoparticles from solution-phase reaction carbonyl complexes with trioctylphosphine. CoMnP (ca. 5 nm in diameter) are nearly monodisperse homogeneous nature. These capable catalyzing at an overpotential 0.33 V 96% Faradaic efficiency when...

The coordination chemistry of the ligands 2-anilino-4,6-di-tert-butylphenol, H[L(AP)], and N,N"'-bis[2-(4,6-di-tert-butylphenol]diethylenetriamine, H(2)[(L(AP))N(L(AP))], has been studied with first-row transition metal ions V, Cr, Fe, Co. are noninnocent in sense that aminophenolato parts, [L(AP)](-) [L(AP)-H](2)(-), can be readily oxidized to their o-iminobenzosemiquinonato, [L(ISQ)](-), o-iminobenzoquinone, [L(ISB)], forms. following neutral octahedral complexes have isolated as...

The investigation of metal-based complexes with potential antitumor activity has been paramount importance in recent years due to the successful use cisplatin against various cancers. Gallium(III) and subsequently developed gallium(III)-containing have shown promising antineoplastic effects when tested a host malignancies, specifically lymphomas bladder cancer. However, molecular mechanism responsible for their anticancer effect is yet be fully understood. We report here first time that...

Abstract A series of cobalt complexes with pentadentate pyridine‐rich ligands is studied. An initial Co II amine complex 1 prone to aerial oxidation yielding a III imine 2 that further converted into an amide 4 in presence adventitious water. Introduction N‐methyl protecting group the ligand inhibits this and gives rise species 5 . Both show electrocatalytic H generation weakly acidic media as well Mechanisms catalysis seem involve protonation H generated situ.

C. Nazari Verani, S. Gallert, E. Bill, T. Weyhermüller, K. Wieghardt and P. Chaudhuri, Chem. Commun., 1999, 1747 DOI: 10.1039/A903778K

Species 1-6 are [M(III)(L)2]ClO4 complexes formed with the PhO--CH=N-CH2-Py imines, (L(I))- and (L(tBuI))-, PhO--CH2-NH-CH2-Py amines, (L(A))- (L(tBuA))-, in which PhO- is a phenolate ring Py pyridine prefix tBu indicates presence of tertiary butyl groups occupying positions 4 6 phenol ring. Monometallic species d5 high-spin iron (1, 2, 3, 4) d10 gallium (5, 6) were synthesized characterized to assess influence ligand rigidity butyl-substituted rings on their steric, electronic, redox...

In this study, we compare the proteasome inhibition capabilities of two anticancer candidates, [Ni(LIA)2] (1) and [Zn(LIA)2] (2), where LIA− is deprotonated form ligand 2,4-diiodo-6-(((2-pyridinylmethyl)amino)methyl)phenol. Species 1 contains nickel(II), a considerably inert ion that favors covalency, whereas 2 zinc(II), labile transition metal predominantly ionic bonds. We report on synthesis characterization using various spectroscopic, spectrometric, structural methods. Furthermore,...

Give me five! Two five-coordinate complexes of iron with geometries that are based on those found in redox-versatile enzymes have been synthesized. The phenolate-rich, pentadentate N2O3 phenylene–diamine/triphenolate ligands confer a low local symmetry the complex so only subtle modifications structure sufficient to completely change sequence which metal and oxidized (see scheme).

A mechanistic investigation of the changes associated with distinct oxidation states cobalt oximes and relevant for catalytic hydrogen generation.

We have designed and characterized modular self-assembled hierarchical films containing a molecular catalyst tethered to an anchoring molecule by means of dipole–induced dipole interactions. In order do so, two new CoIII-based candidates were designed, namely, [CoIIIL1(pyrr)2]ClO4 (Co1) [CoIIIL2(pyrr)2]ClO4 (Co2), where L1 L2 are the respective deprotonated forms N,N′-[4,5-bis(dodecyloxy)-1,2-phenylene]dipicolinamide N,N′-[4,5-bis(methoxyethoxy)-1,2-phenylene]dipicolinamide electrochemical,...

Five gallium(III) complexes described as [GaIII(LX)2]ClO4, where (LX)- is the deprotonated form of a series asymmetric ligands containing pyridine and 4,6-substituted phenol moieties, were synthesized characterized by spectroscopic spectrometric methods. Phenol substituents encompass electron-withdrawing electron-donating methoxy (1), nitro (2), chloro (3), bromo (4), iodo (5) groups. Complexes 1 3 have had their molecular structure solved X-ray crystallography show distinct coordination...

In order to understand and predict structural, redox, magnetic, optical properties of more complex potentially mesogenic electroactive compounds such as [Co(III)(L(t-BuLC))2]ClO4 (1), five archetypical complexes general formula [Co(III)(L(RA))2]ClO4, where R = H (2), tert-butyl (3), methoxy (4), nitro (5), chloro (6), were obtained studied by means several spectrometric, spectroscopic, electrochemical methods. The 2, 4, 6 characterized single-crystal X-ray diffraction, show the metal center...

A new asymmetric pentadentate ligand was designed to impose low symmetry trivalent ions. Five-coordinate Fe3+ and Ga3+ complexes were investigated by crystallographic, electrochemical, electron paramagnetic resonance methods showing enhanced redox reversibility. Calculations performed account for the observed trends.

A nickel-based electro/photocatalyst acts efficiently toward water reduction with a remarkable TON of 3500. Involvement the ligand-reduced [Ni^IL˙] species is proposed.

Two heterometallic complexes [{CuII(HLOX)NiII(N3)}2] and [(tmtacn)CoIII(μ-OH)CuII(LOX)NiII(OH2)2][ClO4]2 (tmtacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) containing the same [CuIINiII] core embedded in an unsymmetrical dicompartmental imine-oxime ligand H4LOX have been synthesized characterized. Their crystal structures show that CuII resides at N(oxime)2O(phenolate)2 site assumes a planar geometry. The NiII is six-co-ordinated bound to N2O4 donor array comprising two iminonitrogens,...

The stabilization of a bivalent oxidation state in cobalt complexes phenolate-based asymmetric tridentate ligands with iodo and bromo substituents is studied. [CoII(LIA)2].2CH3OH (1) [CoII(LBrA)2].CH3OH (2) were characterized by means several spectroscopic spectrometric techniques. molecular structure 1 was determined diffractometric analysis reveals the cobalt(II) ion distorted-octahedral geometry. centrosymmetric metal adopts local D2h symmetry surrounded facially coordinated ligands....

One-way street: An asymmetric iron(III) phenolate complex with amphiphilic and redox properties was used in the formation of Langmuir–Blodgett (LB) films. These were as a basis for nanoscale Au|LB film|Au devices that are capable current rectification.

Abstract The bimetallic catalyst [Co II 2 (L 1 )(bpy) ]ClO 4 ( ), in which L is an [NN′ O ] fused ligand, efficiently reduced H + to CH 3 CN the presence of 100 equiv HOAc with a turnover number 18 and Faradaic efficiency 94 % after h bulk electrolysis at −1.6 V (vs. Ag/AgCl). This observation allowed proposal that this cooperativity associated distance, angle, orbital alignment two Co centers, as promoted by unique Co−N amido −Co environment offered . Experimental results revealed parent...

Abstract A series of cobalt complexes with pentadentate pyridine‐rich ligands is studied. An initial Co II amine complex 1 prone to aerial oxidation yielding a III imine 2 that further converted into an amide 4 in presence adventitious water. Introduction N‐methyl protecting group the ligand inhibits this and gives rise species 5 . Both show electrocatalytic H generation weakly acidic media as well Mechanisms catalysis seem involve protonation H generated situ.

A copper catalyst is active towards water reduction with distinctive pH-dependent mechanisms. The Cu^III–H⁻ intermediate bypassed by PCET processes.

A new pentadentate oxime has been designed to drive the preferential coordination favored by Co(I) in catalysts used for proton/water reduction. The ligand incorporates water upon metal and is soluble. This Co(III) species doubly reduced exhibits H(+) reduction activity presence of weak acids MeCN evolves H2 protonation suggesting that design increases catalyst effectiveness. Superior catalysis observed with a turnover number (TON) 5700 over 18 h. However, yields Co-based nanoparticles,...