Fixation of CO with Epoxides Catalyzed by Pincer-Type Azo-Aromatic Complexes of Cobalt as Catalysts.

Employing a series of azo-aromatic pincer-type cobalt(II) complexes, -, and an imine-based cobalt complex, , a highly efficient catalytic protocol for the cycloaddition of CO with epoxides at low pressure of CO is reported. The electron-withdrawing group-substituted ligands containing complexes and were most efficient. The catalytic protocol with involved a synergistic participation of an azo-aromatic catalyst (0.

Ligand redox controlled amine dehydrogenation and imine hemilability in singlet diradical azo-aromatic Ni(II) complexes: characterization of the electron transfer series of azo-imine complexes of Ni(II).

Herein, using azo-amine (H2L) and azo-imine (L) ligands, singlet diradical Ni(II) complexes [1] and [2] were synthesized from Ni(0)(COD) in THF. In separate reactions, homoleptic Ni complexes, [3a]2+-[3c]2+, were synthesized from [Ni(HO)](ClO) and L, respectively. All these complexes were characterized thoroughly.

A Phosphine-Oxide Cobalt(II) Complex and Its Catalytic Activity Studies toward Alcohol Dehydrogenation Triggered Direct Synthesis of Imines and Quinolines.

Herein, a new pincer-like amino phosphine donor ligand, , and its phosphine-oxide analog, , were synthesized. Subsequently, cobalt(II) complexes and were synthesized by the reaction of anhydrous Co(II)Cl with ligands and respectively. The ligands and complexes were fully characterized by various physicochemical and spectroscopic characterization techniques.

Completely -Phenylene Bridged -Cyclophane: A Missing Link in the Phenylene Bridge -Cyclophane Family.

Unprecedented types of metal-free complete -phenylene bridged -cyclophanes ( and ) have been synthesized via sequential palladium-catalyzed Buchwald-Hartwig -arylation reactions. These cyclophanes may be considered as aromatic analogues of aliphatic group-spaced -macrocycles. These have been characterized fully using physicochemical characterization techniques and finally by single crystal X-ray structure determination.

Alcohol Dehydrogenation-Triggered Selective C3-Alkylation of Indoles by Homogeneous Azo-aromatic Cobalt Catalysts.

Herein, we report azo-benzimidazole containing cobalt complexes (-) for alcohol dehydrogenation-triggered C3-alkylation of indoles. In complexes , ligands are redox noninnocent and showed facile irreversible reduction followed by Co(II)/Co(I) reduction in close-lying potentials. Taking advantage of facile redox events in -, the first aerial dehydrogenation of alcohols to their corresponding carbonyl compounds is explored.

Hemilabile Amine-Functionalized Efficient Azo-Aromatic Cu-Catalysts Inspired by Galactose Oxidase: Impact of Amine Sidearm on Catalytic Aerobic Oxidation of Alcohols.

A series of azo-aromatic copper(II) complexes, [] and a Cu(I) complex, [], with varying amine-functionalized hemilabile pincer-like [] and [], methyl-substituted azo [], and imine [] ligands, were synthesized and characterized. These complexes were investigated for aerobic oxidation of a variety of aromatic alcohols in the presence of 2.0 mol % precatalysts [], cobaltocene (2.

Polymerisation of styrene using pincer type amine functionalized azo aromatic complexes of Co(II) as catalysts.

In the present report, three mononuclear azo-aromatic complexes of Co(II), 1-3, and an imine-based Co(II) complex, 4, were synthesized through a reaction of respective amine-functionalized pincer-like ligands, HL1-4, with CoCl·6HO in the ligand-to-metal ratio of 1 : 1. All the complexes, 1-4, were thoroughly characterized using various physicochemical characterization techniques, single-crystal X-ray structure determination, and density functional theory (DFT) calculations. Complexes 1-4 were explored for the catalytic styrene polymerisation reaction separately in the presence of modified methyl aluminoxane (MMAO).

Azide-Alkyne "Click" Reaction in Water Using Parts-Per-Million Amine-Functionalized Azoaromatic Cu(I) Complex as Catalyst: Effect of the Amine Side Arm.

A series of Cu(II) complexes, - and , were synthesized through a reaction of amine-functionalized pincer-like ligands, , , and a bidentate ligand with CuCl·2HO. The chemical reduction of complex using 1 equiv of sodium l-ascorbate resulted in a dimeric Cu(I) complex in excellent yield. All of the complexes, -, were thoroughly characterized using various physicochemical characterization techniques, single-crystal X-ray structure determination, and density functional theory calculations.

Irreversible Resistive State Switching in Devices with a Homoleptic Cobalt(II) Complex Active Layer.

Molecules with bi-stable electronic transport behaviour have been in upfront research topics of the molecular semiconductor devices in the past few decades due to the use of such materials in resistive data storage devices. Transition metal complexes (TMC) are expected to be potential candidates in regard to the tunable and manifold redox behaviour expecting multiple bulk transport states. Finding alternate mechanisms in such devices with TMC as the active layer materials would revoke the multifaceted approach to the functional gain.

Microwave-Assisted Neat Synthesis of a Ferrocene Appended Phenolphthalein Diyne: A Designed Synthetic Scaffold for Hg Ion.

A C-symmetric internally conjugated 1,3-dialkyne system , containing phenolphthalein as a fluorophore and ferrocene as a redox moiety, has been synthesized via a microwave-assisted synthetic procedure. Compound was synthesized by Cu-catalyzed Glaser-Hay coupling using a microwave reactor in neat condition for the first time. Compound was found to be highly selective toward Fe, Cu, and Hg ions via multichannels.

Dehydrogenation of amines in aryl-amine functionalized pincer-like nitrogen-donor redox non-innocent ligands via ligand reduction on a Ni(ii) template.

We have synthesized a series of new redox non-innocent azo aromatic pincer-like ligands: 2-(phenylazo)-6-(arylaminomethyl)pyridine (HLa-c: HLa = 2-(phenylazo)-6-(2,6-diisopropylphenylaminomethyl)pyridine, HLb = 2-(phenylazo)-6-(2,6-dimethylphenylaminomethyl)pyridine, and HLc = 2-(phenylazo)-6-(phenylaminomethyl)pyridine), in which one side arm is an arylaminomethyl moiety and the other arm is a 2-phenylazo moiety. Nickel(ii) complexes, 1-3, of these ligands HLa-c were synthesized in good yield (approximately 70%) by the reaction of ligands : (NiCl2·6H2O) in a 1 : 1 molar ratio in methanol. The amine donor in each of the ligands HLa-c binds to the Ni(ii) centre without deprotonation.