4411-80-7Relevant academic research and scientific papers
New systems based on 2,2'-dipyridyl-6,6'-dicarboxylic acid diamides for Am-Eu separation
Alyapyshev, Mikhail Yu.,Babain, Vasily A.,Borisova, Nataliya E.,Kiseleva, Rimma N.,Safronov, Dmitry V.,Reshetova, Marina D.
, p. 336 - 337 (2008)
New synergistic extraction mixtures based on 2,2'-dipyridyl-6,6'-dicarboxylic acid diamides and chlorinated cobalt dicarbolide were proposed as highly effective for americium-europium separation in acidic media.
Impact of steric bulk on photoinduced ligand exchange reactions in Mn(I) photoCORMs
Pordel, Shabnam,Schrage, Briana R.,White, Jessica K.,Ziegler, Christopher J.
, (2020)
The investigation of ligand exchange reactions in Mn(I)-based photoactivated CO-releasing molecules, or “photoCORMs,” has largely focused on the electronic effects of the ligand set. In this work, we report the effects of sterically bulky bidentate (NN) ligands on the efficiency for CO release and the formation of photochemical intermediates in fac-[Mn(NN)(CO)3(L)]n+ photoCORMs. The vibrational and electronic absorption spectroscopy and photochemistry of two new Mn(I) photoCORMs with a sterically bulky 6,6′-dimethyl-2,2′-bipyridine ligand, fac-[Mn(6,6′-Me2bpy)(CO)3Br] (6,6′-Me2bpy-Br) and fac-[Mn(6,6′-Me2bpy)(CO)3(py)]+ (6,6′-Me2bpy-py), are reported in comparison to two previously reported analogues, fac-[Mn(4,4′-Me2bpy)(CO)3Br] (4,4′-Me2bpy-Br) and fac-[Mn(4,4′-Me2bpy)(CO)3(py)]+ (4,4′-Me2bpy-py) with the 4,4′-dimethyl-2,2′-bipyridine ligand. The steric demands of the methyl substituents in the 6,6′ positions on bpy significantly distort the structure, as the crystal structure shows contraction between the equatorial CO ligands and tilting of the bidentate ligand relative to the 4,4′-Me2bpy complexes. The movement of the methyl substituents from the 4,4′ to the 6,6′ positions on bpy has little impact on the electronic properties of the complexes, as observed by FTIR and electronic absorption spectroscopy, while the steric bulk of 6,6′-Me2bpy increases the quantum yield of CO release (ΦCO) and increases the lability of the Br? and py ligands compared to the 4,4′-Me2bpy complexes with less steric bulk.
A New Synthesis of 6,6'-Dimethyl-2,2'-bipyridine by Coupling of 2-Bromo-6-methylpyridine with Raney-Nickel as Reagent
Rode, Thomas,Breitmaier, Eberhard
, p. 574 - 575 (1987)
A new reaction of 2-bromo-6-methylpyridine 1 is described.Compound 1, when refluxed in dry toluene with a stochiometric amount of thoroughly dried and degassed Raney-Nickel, yields 6,6'-dimethyl-2,2'-bipyridine-N,N'-nickel dibromide 2.Subsequent hydrolysis of 2 (water), followed by extraction (chloroform) and crystallization from ligroine gives the desired ligand 3, 6,6'-dimethyl-2,2'-bipyridine, a useful reagent in the synthesis of polypyridines and related macrocyclic compounds.
X-ray crystallography and electrochemistry reveal electronic and steric effects of phosphine and phosphite ligands in complexes RuII(κ4-bda)(PR3)2 and RuII(κ3-bda)(PR3)3 (bda?=?2,2′-bipyridine-6,6′-dicarboxylato)
Yazdani, Sima,Silva, Braden E.,Cao, Thomas C.,Rheingold, Arnold L.,Grotjahn, Douglas B.
, p. 63 - 70 (2019)
We have examined coordination of PR3 = triphenylphosphine, triethylphosphine, triisopropyl phosphite, trimethyl phosphite, and 1,3,5-triaza-7-phosphaadamantane (PTA) to the fragment RuII(bda) to better understand how different phosphine and phosphite ligands influence the electronic and structural properties of the RuII complexes. PTA and P(OMe)3 afforded complexes with three phosphorus ligands bound to Ru, with the bda being tridentate (κ3-N,N,O) in complexes 4 and 5; for the other three phosphorus ligands, even in the presence of >2 equiv, only RuII(κ4-bda)(PR3)2 species 1–3 were seen. Both experimental and computational methods were used to study the complexes. Steric effects are the main factor determining whether bis- or tris(PR3) complexes are formed. Cyclic voltammetry studies of the complexes revealed an increase in RuIII/II potential upon having another phosphorus ligand in the equatorial position. Computational studies predict that the additional phosphine ligand in the equatorial plane of 4 engages in significant orbital mixing with the ruthenium center that results in lower energy bonding as compared to the axial phosphine ligands. This work provides the first evaluation of phosphorus ligand steric and electronic effects on the RuII(bda) fragment.
Na2(smbipy) - A bipyridine-derived ligand with chelating sulfonate tags and its 3d metal complexes
Oelkers, Benjamin
, p. 5838 - 5848 (2014)
The sulfonated bipyridine derivative disodium 6,6′-bis(sulfonatomethyl)-2,2′-bipyridine [Na2(smbipy)] was synthesized, and its complexation behaviour towards divalent 3d metals in aqueous solution was explored. The complexes of late 3d metals [M(smbipy)(H2O)2]·H2O (M = Co, Ni, Zn) and [Cu(smbipy)(H2O)] are sparingly soluble in water, and their crystal structures show fourfold equatorial coordination (κ4N,N',O,O') of the smbipy ligand. Ammonia-rich solutions of the NiII and CuII aqua complexes yield the decomplexation products [Ni(NH3)6](smbipy), [Ni(NH3)5(H2O)](smbipy) and [Cu(NH3)4](smbipy)·2H2O. Buffered solutions with a reduced ammonia content lead to [Ni(smbipy)(NH3)2] and [Cu(smbipy)(NH3)3]·2H2O, and the latter shows twofold coordination of the smbipy ligand through the nitrogen atoms only (κ2N,N'). When nearly quantitative amounts of ammonia are applied, two closely related complexes with the core motif [(smbipy)Cu(μ-OH)2Cu] form. Crystal structures of all complexes were obtained, and their features are discussed.
Novel phenanthroline-containing trinuclear double-stranded helicates: Self-recognition between helicates with phenanthroline and bipyridine binding sites
Shaul, Mazi,Cohen, Yoram
, p. 9358 - 9364 (1999)
The ligands 6,6'-bis[(2-methyl-1,10-phenanthrolin-9- yl)methylenoxymethylenyl] 2,2'-bipyridine (1)- and 2,9-bis[(2-methyl-1,10- phenanthrolin-9-yl)methylenoxymethylenyl] -1,10-phenanthroline (2) were prepared and shown to self-assemble into double-stranded [(L)2Cu3]3+-type helicates upon reaction with Cu+. Although the reaction of 1 with AgCF3SO3 afforded the double-stranded helicate [(1)2Ag3]3+, reaction of 2 with this salt yielded a mixture of several complexes, all of apparently double- strand nature, based on their diffusion coefficients. Addition of a large excess of AgCF3SO3 afforded [(2)2Ag3]3+ as the sole product. In addition, it was found that the reaction of Cu+ with mixtures of 1 and 6''6'''-bis[(6-methyl-2,2'-bipyridin-6'-yl)methylenoxymethylenyl]-2''2'''- bipyridine (4) or of 2 with 2,9-bis[(6-methyl-2,2-bipyridin-6'- yl)methylenoxymethylenyl]-1,10-phenanthroline (3) afforded mixtures of homoleptic and heteroleptic helicates. Helicate distribution seems to follow statistical expectations. Mixing of the double-stranded copper helicates of 2 and 3 in DMSO-d6 afforded, after 2 weeks, a statistical mixture of the homoleptic and heteroleptic helicates, i.e., [(2)2Cu3]3+, [(3)2Cu3]3+, and [(2/3)Cu3]3+. However, a statistical mixture was obtained within minutes from the double-stranded silver helicates of 2 and 3 in CD3CN. We conclude therefore that even 2 and 3, which contain three phenanthroline and three bipyridine binding sites, are not 'sufficiently instructed' to avoid the formation of a heteroleptic helicate in the course of their self-assembly process.
Synthesis and characterization of new binaphthyl-linked phenanthroline-, bipyridine-, or pyridine-derived ligands, and the study of their cytotoxic activity
Beynek, Nesrin,Ulucam, Gueherguel,Benkli, Kadriye,Koparal, Ayse Tansu
, p. 2089 - 2096 (2008)
In the present work, we describe the synthesis and characterization of five new versatile acyclic or macrocyclic ligands containing binaphthyl-linked pyridine, bipyridine, or phenanthroline groups in their framework (see Schemes 1-4). The structures of the ligands were elucidated on the basis of elemental analyses, IR, 1H-NMR, 13C-NMR, and FAB mass spectra. The cytotoxicity of these compounds was tested in vitro by using the tetrazolium salt reduction (MTT) assay on A549 (human lung carcinoma epithelial like) cells. All of the tested compounds induced time- and concentration-dependent cytotoxic effect.
2,2′-Dipyridyl-6,6′-dicarboxylic acid diamides: Synthesis, complexation and extraction properties
Alyapyshev,Babain,Borisova,Eliseev,Kirsanov,Kostin,Legin,Reshetova,Smirnova
, p. 1998 - 2005 (2010)
New ligands for complexing of the post-transition metals - diamides of 2,2′-bipyridyl-6,6′-dicarboxylic acid were developed, synthesised and characterised. They were proposed to be effective extractants towards americium. The structures of the amides were studied in solid as well as in solution. The extraction of Am and lanthanides depending on diamide structure, chlorinated cobalt dicarbollide (CCD) - diamide ratio, type of diluent was studied. The optimal conditions for Am/REE separation were determined. The properties of new potentiometric sensors on the base of 2,2′-dipyridyl-6,6′-dicarboxylic acid diamides were studied. The correlation structure vs. properties of ionophores (i.e. extractants), their sensitivity and selectivity in sensor analysis and extraction are discussed.
Structure and DNA cleavage properties of two copper(ii) complexes of the pyridine-pyrazole-containing ligands mbpzbpy and Hmpzbpya
Maheswari, Palanisamy Uma,Lappalainen, Kristian,Sfregola, Michael,Barends, Sharief,Gamez, Patrick,Turpeinen, Urho,Mutikainen, Ilpo,Van Wezel, Gilles P.,Reedijk, Jan
, p. 3676 - 3683 (2007)
The DNA-cleavage properties of the two copper(ii) complexes, [Cu(mbpzbpy)Br2](H2O)2.5 (1) and [Cu(mpzbpya)Cl](CH3OH) (2), obtained from the ligands 6,6′-bis(3,5-dimethyl-N-pyrazolmethyl)-2,2′-bipyridine) (mbpzbpy) and 6′-(3,5-dimethyl-N-pyrazolmethyl)-2,2′-bipyridine-6-carboxylic acid) (Hmpzbpya), respectively, are reported. Upon coordination to Cu II chloride in methanol, one arm of the ligand mbpzbpy is hydrolyzed to form mpzbpya. Under the same experimental conditions, the reaction of mbpzbpy with CuBr2 does not lead to ligand hydrolysis. The ligand mpzbpya is coordinated to a copper(ii) ion generating a CuN3OCl chromophore, resulting in a distorted square-pyramidal environment, whereas with the N 4 mbpzbpy ligand, the CuII ion is four-coordinated in a distorted square planar geometry. Both complexes promote the oxidative DNA cleavage of X174 phage DNA in the absence of reductant. The oxidative nature of the DNA cleavage reaction has been confirmed by religation and cell-transformation experiments. Studies using standard radical scavengers suggest the involvement of hydroxyl radicals in the oxidative cleavage of DNA. Although both compounds do convert form I (supercoiled) DNA to form II (nicked, relaxed form), only complex 1 is able to produce small amounts of form III (linearized DNA). This observation may be explained either by the attack of the copper(ii) complexes to only one single strand of DNA, or by a single cleavage event. Statistical analysis of relative DNA quantities present after the treatment with both copper(ii) complexes supports a random mode of DNA cleavage. This journal is The Royal Society of Chemistry.
Two convenient and high-yielding preparations of 6,6'-dimethyl-2,2'-bipyridine by homocoupling of 6-bromopicoline
Cassol,Demnitz,Navarro,Neves
, p. 8203 - 8206 (2000)
6-Bromopicoline can be reductively homocoupled to provide 6,6'-dimethyl-2,2'-bipyridine in high yield either by an Ni-bpy catalysed electrosynthesis or by a catalytic modification of the Ullmann synthesis employing Pd(OAc)2. Either procedure is operationally simple and represents a considerable improvement over most known syntheses of this important disubstituted bipyridine. (C) 2000 Elsevier Science Ltd.
