(II) perchlorate and pyridine-2-aldehyde in the presence of a base. Comparisons of thermodynamics and ligand-fieldparameters show that dmso is a much weaker ligand compared with pyridine than could be predicted from previous experi- ( 5 mmol) corresponding to complexes 11, 12 and 14 prepared m e n t ~ . Crabtree's catalyst. and oxidative addition of the ortho C-H bond in pyridine N-oxide 50 Organometallic Complexes of Phosphinopyridines and Related Ligands The synthesis and characterization of a mononuclear nickel(II) complex [Ni(L2)](ClO4)2 (1) and an analogous mononuclear copper(II) complex [Cu(L2)](ClO4)2 (2) of a 15-membered azamacrocycle (L2 = 3-(2-pyridyl)-6,8,8,13,13,15-hexamethyl-1,2,4,5,9,12-hexaazacyclopentadeca-5,15-diene) are reported. Chloro (pyridine)cobaloxime. The structural studies revealed that complexes 1 and 2 have similar . . The complex has been characterized by spectral technique and thin-layer chromatography method. The ammonia and acetonitrile complexes, [pyrr2py]Ni(NH3) and [pyrr2py]Ni(NCMe) feature all-nitrogen coordination spheres around nickel consisting of . h2pydco (isocinchomeronic acid or pyridine2,5dicarboxylic acid n-oxide) is an appropriate candidate for constructing new metal organic compounds through covalent bonds with metal ions as well as. Unusual ring opening of a coordinated imidazol-2-ylidene, Dalton Transactions" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Abstract Two structurally novel Co(III) complexes have been successfully constructed from the pyridine-including half-salamo-like ligands (HL 1 and HL 2), namely as [Co(L 1)(N 3) 2] (1) and [Co(L 2)(N 3) 2] (2).The structural features of complexes 1 and 2 have been confirmed by means of single crystal X-ray diffraction experiment. The nickel dichloride complexes of the ligands are paramagnetic. Read "'Pincer' pyridine dicarbene complexes of nickel and their derivatives. . The lower valent pyridine complexes of these metals are composed of carbonyl and nitrosyl counterpart. E : (1) = 1.1 . (II) complexes. Nickel pyridinethiolate complexes as catalysts for the light-driven production of hydrogen from aqueous solutions in noble-metal-free systems J Am Chem Soc . . New pyridine-phosphine ligands of general structure 2-[2-(diarylphosphino)ethyl]pyridine were developed. All complexes have octahedral Ni(II) center(s) and were magnetic. Are you sure you want to send a request to delete this work? The X-ray structural analysis of 4 confirms the formation of a pyrazolate . Achieving the transition metal-catalysed pyridine C3H alkenylation, with pyridine as the limiting reagent, has remained a long-standing challenge. The nickel(II) complex is the easiest to reduce in the series, with E 1/2 = 0.9 V. Figure 7. the nickel catalyst. A few octahedral homoleptic pyridine complexes are known. Incorporating pyridine as the nitrogen side arm facilitated the C-H activation in the PCN ligand and allowed the cyclometallation with nickel to take place at room temperature. Structural, Spectral, and Electrochemical Properties of Nickel(II), Copper(II), and Zinc(II) Complexes Containing 12-Membered Pyridine- and Pyridol-Based Tetra-aza Macrocycles The Ni complex can give a TONcat up to 1340 in the homogeneous photocatalytic system. Binding enthalpies HNi-Py of pyridine to the nickel complexes with dipyridylmethanes containing different ligating anionic residues were determinded as the difference between the enthalpy of the triplet pentacoordinate complex (HNiPy) and the sum of the enthalpies of the singlet tetracoordinate complex (HNi) and the non-binding pyridine (HPy). Nickel( ) complexes with L2a-L2c, when treated with an excess of NaCN, liberated macrocyclic ligands that could be isolated by extraction in chloroform or methylene chloride followed by solvent evaporation. Complexes of pyridine and its derivatives are a cornerstone to diverse chemical reactions. It . Bromochlorotetrakis(pyridine)nickel(II) has been prepared and characterized by means of elemental analysis, infrared spectra, conductance measurements and electronic spectra. CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): R factor = 0.081; wR factor = 0.321; data-to-parameter ratio = 13.7. New PCN Py pincer nickel complexes have been synthesized through a short synthetic route. This The Ni complex is also an active electrocatalyst for reduction of protons. ligand in 1) have been explored with considerable depth.2,3 In particular, the imidazole-derived ligands, The complexes were identified using NMR spectroscopy, superconducting quantum interference device (SQUID), and X-ray crystallography. The newly synthesized nickel [NiIILN2PY3]2+ complex was catalytic and showed better stability during the electro/photocatalytic water reduction, compared to the first three nickel complexes. This result is consistent with DMAP being a more strongly donating ligand than unsubstituted pyridine. Two types of ImPy salts were prepared as new C,N-bidentate ligand precursors; py-ImPy . Read "Nickel and iron complexes with oxazoline- or pyridine-phosphonite ligands; synthesis, structure and application for the catalytic oligomerisation of ethylene, Dalton Transactions" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Heine et al. Once cooled the solution was filtered under suction and the Filtrate (aqua blue liquid in Buchner flask) was added to the refluxing . Unlike their Schi base pre- cursors, these ligands were stable towards hydrolysis and could be used to prepare complexes of other metals. Molar magnetic moment and exchange energy of nickel(II) complex with pyridine-substituted nitronyl nitroxide radical measured using SQUID method is given in this chapter. Synthesis and structure of nickel 2-methyl-5-propylthio-8-hydroxyquinolinate - pyridine adduct Ni[C{sub 9}H{sub 4}(CH{sub 3})(SC{sub 3}H{sub 7})NO]{sub 2}(C{sub 5}H{sub 5}N){sub 2}; Kompleksy nikelya (II) s 8-oksikhinolinom i 8-merkaptokhinolinom. The complex of LarB with NAD +, an analog of NaAD, reveals the formation of a covalent adduct between the active site Cys221 and C4 of NAD +, resulting in a boat-shaped dearomatized pyridine ring. The pyrrolyl pyridine pincer ligand, a relatively new class of dianionic, tridentate, nitrogen-based ligands in coordination chemistry, was prepared starting with a modified method for the synthesis of pyrrolyl pyridine. The most common stoichiometries found in nickel (H) pyridine and substituted pyridine complexes are NiX2L4 and NiX2L2 where X is a mononegative ion and L is pyridine or a substituted pyridine. Incorporating pyridine as the nitrogen side arm facilitated the C-H activation in the PCN ligand and allowed the cyclometallation with nickel to take place at room temperature. The flask was warmed until all the green solid has dissolved and a white solid has formed. The nickel complexes are four-coordinate and adopt a square-planar geometry. cobalt(II) and nickel(II) complexes o f certain pyridine carboxylic acids and py ridine-3-sulfonic acid: Magnetic and spectral studies. Racemic nickel(II) pyridine-2-aldoximate complexes capped by 2,2-bipyridine and 1,10-phenanthroline: Syntheses, structures and magnetic properties. The complex having the most planar coordination geometry appeared to have the highest catalytic efficiency for proton reduction in DMF ( ic / ip = 50, kobs = 490 s -1 at 0.1 V/s) using acetic acid as the proton source. (pyrazolylmethyl)pyridine nickel(II) & iron(II) complexes' is my original work that was carried out in the Discipline of Chemistry, School of Chemistry & Physics of the College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Pietermaritzburg Campus, South Africa. Although several nickel SCS pincer complexes have previously been reported (8-10), none exhibited an essential feature present in the active site of lactate racemase, namely a pyridinium-based pincer backbone.According to the proposed enzyme mechanism, the pyridinium group enables ligand participation in the hydride transfer reaction, which is likely impossible for a more conventional . Ni(bpy)3Cl2 was firstly found to be an active material for photocatalytic CO2 reduction. Octahedral complexes [ edit] trans - [MCl 2 (pyridine) 4] n+ is a common type of transition metal pyridine complex. NICKEL(II) PINCER COMPLEXES SUPPORTED BY 2,6-BIS(3,5-DITOLYL-2-PYRROLYL)PYRIDINE by ABHIJIT PRAMANIK . The title nickel complexes showed comparable activities with 8-arylimino-5,6,7-trihydroquinolyl nickel analogues; whilst both exhibited higher activities than did the 2-iminopyridyl nickel analogue due to the enhancement of the ring-tension of cyclic-fused pyridine derivatives. Abstract It was of inter<)st to vary the substituent group on the pyridine ring in order to obsel'\'e the effects on the nickel-nitrogen coordinate bonds. This compound displays pyridine in this complex is retained tenaciously; a molar conductivity (in methanol) of 89.7 ohms-' drying in vacuo over Pz06causes no apparent loss. Each Ni II atom is coordinated by two O and four N atoms . Silina, E, Bankovsky, Yu, Pech, L, Ashaks, J, and Belsky, V. Nickel (II) complexes with 8-hydroxyquinoline and 8-mercaptoquinoline. The compounds have been analysed and structures have been . Cyclic voltammograms of compounds 1 - 3 and 5 in MeCN. 2 Introduction Within the diverse field of N-heterocyclic carbene metal complexes,1 ligand systems involving a 'pincer' binding geometry with a range of donor groups have been extensively studied.2,3,4 As a subset, CNC 'pincer' ligands based on pyridine with pendant NHC donors (e.g. (2018) investigated the ability of pyridine . 9. in Ni(II) ion and 0.1 N. in X-ray and UV photoelectron-spectroscopic studies of pyridine adsorbed on evaporated nickel and palladium in the temperature range 140-385 k. . No nickel pyridine dipyrrolide complexes have been reported thus far. Additionally, ESR spectra of NiCl(IPr)(pyridine) were taken in toluene. The new nickel (II) complex has also been screened for antibacterial and antifungal activities against various pathogenic bacteria and fungi. Reduction of these nickel(II) complexes lead to distorted square planar complexes with the halide bent ~20 out of the plane. These complexes had three-coordinate Y-shaped geometries in both the solid and solution states. Perhaps the most closely related compounds are the four-coordinate platinum (VIWSIF; Komine et al., 2014), palladium (XIKKIO, XIKKOU; Yadav et al., 2018) and zinc (VIWSIF; Komine et al., 2014) complexes featuring all-nitrogen coordination spheres at the metal. Formation constants for metal complexes of Cu(II), Ni(II), and Ag(I) with some substituted pyridine ligands were determined in a nitrate salt solution of the ligand (0.5 F KNO3 + 0.1 F HL) at 25 C Complexes 3-6 were single crystals. As foretelled for a high spin d 8 system with two unpaired electrons which falls in the range expected for octahedral Ni(II) compounds . Two bulky phosphinopyridine ligands (6-mesityl-2-((diarylphosphino)methyl)pyridine, PN) were successfully prepared by means of Suzuki coupling of mesitylboronic acid with 6-bromo-2-picoline followed by phosphinylation. Previously, we disclosed that the use of . J. Chem. This book is the Sodium thiocyanate (0.601g) was dissolved in Ethanol (11cm3), to this nickel nitrate hexahydrate (0.773g) was added. Pyridine also enhanced the stability of -hydrogen-containing alkyl . A nickel pyridine-selenolate complex is an efficient photocatalyst for H 2 generation. Pyridine also enhanced the stability of -hydrogen-containing alkyl . The ligands could be conveniently synthesized in good yields. The macrocyclic ligand is formed during the reaction of 4,4,9,9-tetramethyl-5,8-diazadodecane-2,11 . Nickel(II) dichloride complexes with a pyridine-chelated imidazo[1,5-a]pyridin-3-ylidene py-ImPy ligand were developed as novel catalyst precursors for acrylate synthesis reaction from ethylene and carbon dioxide (CO2), a highly promising sustainable process in terms of carbon capture and utilization (CCU). The understanding and appreciation of the pyridine N-electrons have enormous long- range ramifications in the future design of industrial catalysts and drugs. Graphene-encapsulated nickel nanoclusters are a feasible strategy to inhibit the nickel deactivation of nickel-based catalysts. Owing to the relatively wide C-N-C angle, the 2,6-hydrogen atoms interfere with the formation of [M (py) 6] z complexes. comp lex ions formed by Ni(II) ion and pyridine compounds. The reduction products of a series of divalent (pyrox)Ni complexes establish the redox activity of pyrox in stabilizing electron-rich Ni(II)-alkyl and -aryl complexes by adopting a ligand-centered radical . The magnetic moments of the complexes were measured. The color of nitromethane solutions of this square-planar complex turns from red to cyan, purple, blue, yellow-green, and pink following addition of halides, acetonitrile, water, pyridine, and 2,2'-bipyridine, respectively. 1972, 50, 1307-1314. Pyridine-functionalized Ni-NHC complexes have been prepared and characterized by various methods. The electronic structures of N-ligand supported nickel complexes appear to vary depending on the actor ligands and the coordination number. While this obstacle was surmountable with 4-methoxypyridine, pyridine is acylated less eciently than 4-methoxypyridine, so a greater amount of free pyridine would be expected to be present in the reaction mixture.18 Another prin-cipal concern was whether the catalyst could enforce high [Ni(C 6 H 4 N 2) 2 (H 2 O) 4](O 2 CC 6 H 4 CO 2) - 4H 2 O, has been synthesized and studied by single-crystal X-ray diffraction. Spectrophotometric titrations of [Ni (L)] (BF4)2 were performed with neutral and negatively charged ligands. The extended aromatic system of pyridine-like ligands influences considerably the molecular structure of prepared nickel complexes. A survey of NiII complexes involving pyridine-3-carbonitrile as ligand led us to some other related structures. Complexes of formula NipysX2 have been found to correspond to either [NiX2py4]-2py (X = NCS, NCO)818 or [Ni (N03)2py3]-3py.819. the acid site of the catalyst was analyzed by pyridine infrared before and after the . A series of nickel ( II) tris (2-pyridylmethyl)amine (TPA) complexes featuring appended hydrogen bonds (H-bonds) to halides (F, Cl, Br) was synthesized and charcterized. L] 2 were prepared by the reaction of stoichiometric amounts of pyridine N-oxide, 2-methylpyridine N-oxide, 3-methylpyridine N-oxide, and triphenylphosphine oxide with nickel(II) mono-, di-, and trichloroacetates in methanol.The complexes were characterized by elemental analyses, conductance, magnetic moments, IR and . Can. Cyclic voltammograms of these nickel(II) complexes suggest that more reduced states can be achieved. tetradentate ligand in the equatorial plane and one coordinat- all complexes are air and moisture stable in the solid Experiment 2.1. The Journal of Physical Chemistry B 2003, 107 . In this system, HZSM-5 was a micron molecular . The field strengths of the ligands , determined from the spectra of their nickel(II) complexes, correlate well with the observed magnetic behaviour of their iron(II) complexes. The phosphorus substituents in these bidentates are 2-tolyl, 2-anisyl, and mesityl. Kinetics of the nickel(II)-[2-(4-dimethylaminophenylazo)pyridine] reaction in pyridine and in pyridine-nitromethane. 2. Nickel (II) complexes of the above bases with nitrate, glycollate and lactate as anion have also been isolated. The higher valent rhenium accommodates oxo ligands along with anionic monodentate and chelating ligands. Abstract We report a homologous series of nickel ( II) complexes supported by N -heterocyclic carbene - pyridine ( R bimpy, R = Me, Et, Pr) ligands that exhibit high selectivity for reducing carbon dioxide over water under electrocatalytic conditions. The asymmetric unit of the crystal structure of the title complex, [Ni(C18H12N2O3)(C5H5N)3] 3C5H5N, contains two independent Ni II complex molecules and six uncoordinated pyridine molecules. ~ ~Similar '' donor numbers are reported for dmso (29.8) according to literature methods and 33% aqueous NaOH . Adduct of his oxine nickel with pyridine, -and -picoline have been prepared. [Pg.76] Now, a nickel-aluminium pincer complex offers new mechanistic insight into transmetalation, and new potential for reactivity. Pyridine Adsorption and Acid/Base Complex Formation on Ultrathin Films of -Al2O3 on NiAl(100). Reactions at the azomethine C N bonds in the nickel(II) andcopper(II) complexes of pyridine-containing Schi-basemacrocyclic ligands Aida M. Herrera,a Ganna V. Kalayda,a Jeremy S. Disch,a Jerey P. Wikstrom,a Ivan V. Korendovych,a Richard J. Staples,b Charles F. Campana,c Alexander Y. Nazarenko,d Terry E. Haasa and Elena V. Rybak-Akimova*a a Department of Chemistry, Tufts University . Mechanistic studies on this complex presented further evidence to disregard the NiIII-H- formation during catalytic cycle. pyridylmethyleneaminomethyl)pyridine(StructureI),which contains the -N=GC=N-G-G=N-group,and to investigate theirstereochemistrybymeans of magnetic,spectraland From the obtained band positions the ligand . The field strengths of (1a) and (1b) are found to be marginally less than those of the isomeric ligands 2,6-di(thiazol-4-yl)pyridine (2a) and 2,6-di(2-methylthiazol-4-yl . Pyridine fused with a furan ring (fupy), and its dimethyl derivative, have been used for the first time as ligands to synthesize potentially new Werner clathrates. Title Pyridine adduct of nickel(II) complex with 1-(3-hydroxy-2-naphthyl)-5-(phenyl)pent-4-ene-1,3-dione Book Title Magnetic Properties of Paramagnetic Compounds Complexes 1 and 2 are racemic, namely, each molecule has a chiral center of or , thereby forming NO-trans- and - geometries in the solid state. The Ni(II) complex has a magnetic moment located in the range 3.20 BM. Copper(II) complex gave a value of magnetic moment 1.74 BM . 2013 Oct 2;135(39):14659-69. doi: 10.1021/ja405257s. the nickel ion in complex 1a is coordinated from 1a and 2a via anion exchange by adding a solution of the in a square-pyramidal geometry, with the donor atoms of the complex in methanol to a boiling methanol solution of nh4pf6. which is the fundamental reason for the extremely complex final products . Studies in Some Nickel (ll) Complexes. This article is part of the themed collection: Artificial Photosynthesis Spectrophotometric titration suggested that the nickel(II) complex could intercalatively bind to DNA via the planar dipicolinic acid moiety with a moderate binding strength of 1.6 10 4 M -1 , and these results were further proved by the systematic studies of viscosity, ethidium bromide (EB) displacement and melting temperature experiments . which may well serve as a standard for complexes Bis-(2-pyridinaldoxime)-nickel(II), [Ni(POX)2], which are uni-univalent electrolytes in methanol. Inorganic Chemistry 1973 , 12 (6) , 1259-1265. Introduction of the redox processes on structural rearrangements of nickel complexes.8 In this work, besides the effect of the pH on the Macrocyclic polyamines, like cyclen or cyclam, bearing co- coordination of a pyridine pendant arm on complexes of ordinating pendant arms have attracted a lot of attention1 cyclen- and cyclam-pyridine . The CO stretch of the nickel-bound carbon monoxide ligand of [pyrr2py]Ni(CO) has been observed at 2101 cm1. A facile heterogeneous photocatalyst system that consists of a nickel complex and cadmium sulfide (CdS), which act as the catalyst and light antenna, respectively, was developed to the efficiency photocatalytic activation and conversion of CO2. New PCN Py pincer nickel complexes have been synthesized through a short synthetic route. of plane bending of C-H of pyridine ring appeared at 705-764 cm-1.21 CH 2 rocking and Cu-N stretching vibration mode of ethylenediamine were appeared about 850-950 cm-1 and 500-610 cm-1, respectively for both complexes.21 The IR spectrum of complex2 shows NH stretching at 3366 cm-1 and a band at 3056 cm-1 attributed to the symmetric stretch The CO binding constants range from 1.3 x 10{sup 2} to 2.8 x 10{sup 5} M{sup -1} at 25 {degrees}C in acetonitrile. A nickel(II) terephthalate complex, viz. The Mn (I) complexes quickly react with air and oxygen. Besides, promoting the photo-generated electrons transfer from . The electronic spectrum in a 10% solution of pyridine in chloroform has been recorded at room temperature and then resolved into precise positioned bands by Gaussian analysis. Reactivity of nickel(II) and copper(II) complexes of a -aminohydrazone ligand with pyridine-2-aldehyde: macrocyclization vs unprecedented pyrazole ring synthesis via C-C bond-forming reaction. Sampl e solutions that were 5 x 10-4 r-. Hitoshi Miyasaka, Sachie Furukawa, . Reduction to the nickel ( I) state provided access to an unusual nickel ( I) fluoride complex stabilized by H-bonds, enabling structural and spectroscopic characterization. D. C. Patel; R. C. Sharma; P. K. Bhattacharya. Complexes with cyclam as co-ligand were more thermally stable than those with pyridine and its derivative, L. Complexes 3 and 4 were mesomorphic after partial loss of The phosphinitooxazoline 4,4-dimethyl-2-[1-oxy(diphenylphosphine)-1-methylethyl]-4,5-dihydrooxazole (9), the corresponding phosphinitopyridine ligands 2-ethyl-[1'-methyl-1'-oxy(diphenylphosphino)]pyridine (11) and 2-ethyl-6-methyl-[1'-methyl-1'-oxy(diphenylphosphino)]pyridine (12), which have a one-carbon spacer between the phosphinite oxygen and the heterocycle, and the homologous .
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