366-18-7Relevant articles and documents
INVESTIGATION OF THE INTERACTION OF PYRIDINE WITH THE SURFACE OF LAMINAR SILICATES BY THE METHOD OF OPTICAL ELECTRONIC SPECTROSCOPY.
Sivalov,Tarasevich
, p. 214 - 218 (1981)
A study of the nature of the active sites on the surface of laminar silicates and an attempt to identify those that are responsible for the observed conversion of sorbed pyridine on the surface of laminar silicate to more complex formations characterized by a rather developed system of conjugated pi -bonds are discussed.
Cartwright et al.
, p. 211,212, 218, 219 (1979)
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Dearmond et al.
, p. 3388,3391 (1979)
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Cation-Assisted Ligand Photosubstitution in Transition-Metal Complexes. Photoreactions of Ru(bpy)32+ with Ag+ in Acetonitrile
Foreman, T. K.,Bonilha, J. B. S.,Whitten, D. G.
, p. 3436 - 3439 (1982)
Irradiation of Ru(bpy)32+ in the presence of Ag+ in acetonitrile leads to the photosubstitution product Ru(bpy)2(CH3CN)22+.The reaction does not occur in the absence of Ag+ or acetonitrile; although Ag+ quenches the luminescent MLCT state of Ru(bpy)32+, a kinetic analysis indicates the photosubstitution does not originate from this excited state.The most reasonable mechanism for the process involves decay of the MLCT state via a d-d excited state to a ligand-labilized intermediate which is interpreted by Ag+ in a process which assists the substitution by removal of a bpy ligand.This mechanism is thus parallel to anion-induced substitution reactions which evidently proceed via competitive anion-ligand capture of the same or similar intermediates.
Acid directed in situ oxidation and decarboxylation of 4,4′,6, 6′-tetra-methyl-2,2′-bipyridine: Synthesis and structural characterisation of 4,4′,6-tri-carboxy-2,2′-bipyridine and its copper(II) coordination polymer
Kelly, Niamh R.,Goetz, Sandrine,Hawes, Chris S.,Kruger, Paul E.
, p. 102 - 109 (2013)
The reaction of either 4,4′,6,6′-tetramethyl-2,2′- bipyridine, L, or 4,4′,6,6′-tetracarboxy-2,2′-bipyridine, H4L, with Cu(OAc)2·H2O under acidic hydrothermal conditions (50:1 H2O/HNO3; 160 °C) led to the formation of crystalline {[Cu(HL′)(H2O)]·H 2O}, 1, which was structurally characterised to identify H 3L′ as 4,4′,6-tricarboxy-2,2′-bipyridine. Clearly, in situ mono-decarboxylation of a tetracarboxylic acid ligand gave the tricarboxy-analogue, H3L′. The structure of 1 consists of a 1D coordination polymer that cross-links through hydrogen-bonding between adjacent carboxylic acid and carboxylate groups, as well as through an aqua ligand and lattice water molecule, to form a densely interconnected 3D network. Regioselective mono-decarboxylation of L or H4L at the 6′-carboxylic acid position may also be affected by heating L or H 4L in acidic solution under hydrothermal conditions (2:1 H 2O/HNO3; 160°C) to yield crystalline 4,4′,6-tricarboxy-2,2′-bipyridinium nitrate hydrate {[H 4L′][NO3]·H2O}, 2, which was also structural characterised. The structure of 2 features an array of hydrogen-bonding interactions that generate a 3D network. More forceful heating of the acidic solution at 180°C led to double decarboxylation and the formation of 4,4′-dicarboxy-2,2′-bipyridine, whereas heating at 200°C led to total decarboxylation and the formation of 2,2′- bipyridine. Details of the structures of 1 and 2 along with their synthesis are discussed.
DIMER FORMATION IN THE REACTION OF ARYL HALIDES CATALYZED BY NICKEL COMPLEXES
Budnikova, Yu. G.,Kargin, Yu. M.,Yanilkin, V. V.
, p. 1299 - 1300 (1992)
The synthesis of diaryls catalyzed by electrochemically generated zero-valent nickel with 2,2'-dipyridyl as the ligand was carried out from aryl halides in high yield.Feasibility was demonstrated for synthesizing the catalyst itself by the anodic dissolution of nickel in the presence of 2-bromopyridine in a diaphragmless cell.Keywords: synthesis, diaryls, aryl halides.
Phototoxicity of strained Ru(II) complexes: Is it the metal complex or the dissociating ligand?
Azar, Daniel F.,Audi, Hassib,Farhat, Stephanie,El-Sibai, Mirvat,Abi-Habib, Ralph J.,Khnayzer, Rony S.
, p. 11529 - 11532 (2017)
A photochemically dissociating ligand in Ru(bpy)2(dmphen)Cl2 [bpy = 2,2′-bipyridine; dmphen = 2,9-dimethyl-1,10-phenanthroline] was found to be more cytotoxic on the ML-2 Acute Myeloid Leukemia cell line than Ru(bpy)2(H2O)22+ and prototypical cisplatin. Our findings illustrate the potential potency of diimine ligands in photoactivatable Ru(ii) complexes.
Ligand-free Stille cross-coupling reaction using Pd/CaCO3 as catalyst reservoir
Coelho, Aline V.,de Souza, Andréa Luzia F.,de Lima, Paulo G.,Wardell, James L.,Antunes
, p. 7671 - 7674 (2007)
Stille reactions between halobenzenes and other substituted (hetero)arenes and tributylphenyltin were carried out in ethanol-water solution using Pd/CaCO3 as catalyst in a ligand-free system. The catalyst could be recycled three times without any loss of activity. The ethanol-water solution, after removal of the catalyst and extraction of the product, was found to have catalytic activity, thus showing the presence of soluble Pd(0)/Pd(II) species that can be regarded as the true catalysts.
Novel synthesis method of 2, 2 '-dipyridyl
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Paragraph 0017-0020, (2021/03/10)
The invention discloses a novel synthesis method of 2, 2 '-dipyridyl. According to the method, 2, 2'-dipyridyl with the purity of 99.8% or above is obtained by taking 2-chloropyridine as an initial raw material and adopting a supported catalyst through coupling reaction and aftertreatment at the temperature of 50-60 DEG C. The method has the advantages of mild reaction conditions, realization of the reaction at 50-60DEG C, short reaction time, completion of the reaction in 2-5h, simple extraction, freezing recrystallization, high conversion rate, repeated application of the catalyst, simple and efficient production operation, low cost and stable product quality, and overcomes the defects of high catalyst cost, difficult recovery, and low catalytic efficiency. Meanwhile, the problems of environment and safety in the production process are solved.
Pd-catalyzed oxidative homocoupling of arylboronic acids in WEPA: A sustainable access to symmetrical biaryls under added base and ligand-free ambient conditions
Appa, Rama Moorthy,Lakshmidevi, Jangam,Naidu, Bandameeda Ramesh,Venkateswarlu, Katta
, (2021/01/11)
Symmetrical and unsymmetrical biaryls comprises a diverse class of biologically eloquent organic compounds. We herein report, a quick and eco-friendly protocol for the synthesis of biaryls by an oxidative (aerobic) homocoupling of arylboronic acids (ABAs) using Pd(OAc)2 in water extract of pomogranate ash (WEPA) as an efficient agro-waste(bio)-derived aqueous (basic) media. The reactions were executed at ambient aerobic conditions in the absence of external base and ligand to result symmetrical biaryls in excellent yields. The use of renewable media with an effective exploitation of waste, short reaction times, excellent yields of products, easy separation of the products, unnecessating the external base, oxidant, ligand or volatile organic solvents and ambient reaction conditions are the vital insights of the present protocol.