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1.
Charron G Bellot F Cisnetti F Pelosi G Rebilly JN Rivière E Barra AL Mallah T Policar C 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(10):2774-2782
Two organic ligands based on a sugar-scaffold derived from galactose and possessing three O-CH(2)-pyridine pendant arms at the 3-, 4-, and 5-positions of the galactopyranose that act as chelates afford mononuclear complexes when reacted with a Ni(II) salt. The magnetization behavior in the form of M=f(H/T) plots suggests the presence of appreciable magnetic anisotropy within the two complexes. The analysis of the EPR spectra performed at two different temperatures (7 and 17 K) and at three frequencies (190, 285, and 380 GHz) leads to the conclusion that the anisotropy has a high degree of axiality (E/D=0.17 for the two complexes), but with a different sign of the D parameter. The spin hamiltonian parameters D and E were reproduced for the two complexes by using calculations based on the angular overlap model (AOM). The structural difference between the two complexes responsible of the sign of the D parameters was also determined using AOM calculations. A thorough analysis of the structures showed that the structural differences in the coordination sphere of the two complexes responsible of the different D parameter sign result from the nature of the sugar scaffolds. In complex 1, the sugar scaffold imposes an intramolecular hydrogen bond with one of the atoms linked to Ni(II); this arrangement leads to a distorted coordination sphere and positive D value, while the absence of such a hydrogen bond in complex 2 leads to a less distorted environment around the Ni center and to a negative D value. 相似文献
2.
《Journal of Coordination Chemistry》2012,65(23):3893-3911
AbstractTwo complexes of 5,6-di(2-furyl)-3-(2-pyridyl)-1,2,4-triazine (L), [Co(L)2(NO3)2] (1), and [Ni(L)2(NO3)2] (2), were prepared and identified along with L by elemental analysis, FT-IR, UV-Vis, and 1H NMR spectroscopies and single-crystal X-ray diffraction. All coordination modes of the 1,2,4-triazine unit and also of the nitrato ligand in coordination with cobalt and nickel atoms were studied by analysis of the Cambridge Structural Database (CSD) to compare with the new results. X-ray structure analysis of complexes 1 and 2 revealed that the metal atom in both complexes has an octahedral geometry with MN4O2 environment (M: Co (1), Ni (2)). The ligand acts as a bidentate NtzNpy-donor and forms a five-membered planar chelate ring. In addition to the hydrogen bonds, the crystal network is stabilized by π–π stacking interactions between pyridine rings of the ligands of adjacent complexes. The thermodynamic stability of the two conformational isomers of the 5,6-di(2-furyl)-3-(2-pyridyl)-1,2,4-triazine and their charge distribution patterns were studied by DFT and NBO analysis, respectively. The ability of the uncoordinated ligand conformers and complexes 1 and 2 to interact with nine selected biomacromolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS, and Top II) was investigated by docking calculations and compared with that of doxorubicin. Also an analog of the ligand in which the furyl rings are replaced by phenyl groups is included in these studies. 相似文献
3.
Stenson PA Board A Marin-Becerra A Blake AJ Davies ES Wilson C McMaster J Schröder M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(8):2564-2576
The dithiosalicylidenediamine Ni II complexes [Ni(L)] (R=tBu, R'=CH2C(CH3)2CH2 1, R'=C6H4 2; R=H, R'=CH2C(CH3)2CH2 3, R'=C6H4 4) have been prepared by transmetallation of the tetrahedral complexes [Zn(L)] (R=tBu, R'=CH2C(CH3)2CH2 7, R'=C6H4 8; R=H, R'=CH2C(CH3)2CH2 9, R'=C6H4 10) formed by condensation of 2,4-di-R-thiosalicylaldehyde with diamines H2N-R'-NH2 in the presence of Zn II salts. The diamagnetic mononuclear complexes [Ni(L)] show a distorted square-planar N2S2 coordination environment and have been characterized by 1H- and 13C NMR and UV/Vis spectroscopies and by single-crystal X-ray crystallography. Cyclic voltammetry and coulombic measurements have established that complexes 1 and 2, incorporating tBu functionalities on the thiophenolate ligands, undergo reversible one-electron oxidation processes, whereas the analogous redox processes for complexes 3 and 4 are not reversible. The one-electron oxidized species, 1+ and 2+, can be generated quantitatively either electrochemically or chemically with 70 % HClO4. EPR and UV/Vis spectroscopic studies and supporting DFT calculations suggest that the SOMOs of 1+ and 2+ possess thiyl radical character, whereas those of 1(py)2 + and 2(py)2 + possess formal Ni III centers. Species 2+ dimerizes at low temperature, and an X-ray crystallographic determination of the dimer [(2)2](ClO4)2.2 CH2Cl2 confirms that this dimerization involves the formation of a S-S bond (S...S=2.202(5) A). 相似文献
4.
5.
Elmasry M. A. A. Gaber A. Khater E. M. H. 《Journal of Thermal Analysis and Calorimetry》1998,52(2):489-495
The thermal decompositions of nickel(II) nitrate hexahydrate and iron(III) nitrate nonahydrate were followed. It was found
that the final decomposition products were NiO at 623 K and Fe2O3 at 523 K, respectively. The two salts exhibited only endothermic
peaks and a loss in mass until constant mass was attained. The decomposition reactions and the compounds corresponding to
each reaction were established. A heating rate of 1 K min-1 revealed several intermediates; higher heating rates shifted the
peaks to higher temperatures. The use of an air flow during decomposition shifted the reactions to lower temperatures.
The DTA for the mixed salts was found to be an overlap and the TG a summation of the results for the two individual salts.
At 773 K, the decomposition products were composed of three phases: NiO, Fe2O3 and NiFe2O4. When these products were heated
to 1773 K, only NiFe2O4 was identified by X-ray diffraction.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
NiL2Bipy·1.5EtOH, CoL2Bipy·1.5EtOH, and CoL2Phen·0.5EtOH mixed-ligand complexes with a fixed cis` position of paramagnetic ligands (L = 4-(3',3',3'-trifluoro-2'-oxopropylidene)-2,2,5,5-tetramethyl-3-imidazolidine-1-oxyl) have been synthesized and studied by X-ray crystallography. 相似文献
7.
M. A. A. Elmasry A. Gaber E. M. H. Khater 《Journal of Thermal Analysis and Calorimetry》1996,47(3):757-763
The thermal decomposition of the ferric and nickel acetate salts has been followed. It was found that the heating rate affects the decomposition steps. For a heating rate of 1 K min–1 the product is either Fe2O3 or NiO. For a higher heating rate the suboxides are obtained and reoxidized again on further heating. The decomposition of the mixed salt is an overlap of the DTA for the separate salts but the decomposition reactions are shifted to lower temperatures.We would like to thank Prof. Dr. N. Afify, Phys. Dept., Fact. Science, Assiut University, for experimental assistance and valuable discussions. 相似文献
8.
Rebilly JN Charron G Rivière E Guillot R Barra AL Serrano MD van Slageren J Mallah T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(4):1169-1177
Pentacoordinate complexes in which Ni(II) is chelated by the tridentate macrocyclic ligand 1,4,7-triisopropyl-1,4,7-triazacyclononane (iPrtacn) of formula [Ni(iPrtacn)X(2)] (X=Cl, Br, NCS) have relatively large magnetic anisotropies, revealed by the large zero-field splitting (zfs) axial parameters |D| of around 15 cm(-1) measured by frequency-domain magnetic resonance spectroscopy (FDMRS) and high-field high-frequency electron paramagnetic resonance (HF-HFEPR). The spin Hamiltonian parameters for the three complexes were determined by analyzing the FDMRS spectra at different temperatures in zero applied magnetic field in an energy window between 0 and 40 cm(-1). The same parameters were determined from analysis of HF-HFEPR data measured at different frequencies (285, 380, and 475 GHz) and at 7 and 17 K. The spin Hamiltonian parameters D (axial) and E (rhombic) were calculated for the three complexes in the framework of the angular overlap model (AOM). The nature and magnitude of the magnetic anisotropy of the three complexes and the origin of the influence of the X atoms were analyzed by performing systematic calculations on model complexes. 相似文献
9.
《Analytical letters》2012,45(10):1009-1023
Abstract The dissociation constant of 4–(8-quinolylazo)- l -aminonaphtalene (QAN) and conditional formation constants of its complexes with Cu(II), Ni(II) and Hg(II) were measured spectrophotometrically. The use of QAN as metallochromic indicator in copper, nickel and mercury titrations with EDTA was studied. QAN improves PAN and XO results in Cu(II) and Hg(II) titrations and is comparable to Murexide in Ni(II) titration. 相似文献
10.
A review of the studies dealing with the removal of chromium, cadmium, and nickel ions with different adsorbents published in the literature between 2014 and 2018 is given in tabular form, along with the adsorption conditions, adsorption isotherm, and kinetic models applied by the authors to model the experimental data and adsorption capacities. The review focuses on the efficiency of ion removal. 相似文献
11.
Fernanda M. de Oliveira Affonso C. Gonçalves Jr Douglas C. Dragunski Mariana G. Segatelli 《International journal of environmental analytical chemistry》2013,93(10):1061-1071
The present paper describes the feasibility of on-line preconcentration of nickel ions from aqueous medium on Ni(II)-imprinted cross-linked poly(methacrylic acid) (IIP) synthesised through a double-imprinting method and their subsequent determination by FAAS. The proposed method consisted in loading the sample (20.0 mL, pH 7.25) through a mini-column packed with 50 mg of the IIP for 2 min. The elution step was performed with 1.0 mol L?1 HNO3 at a flow rate of 7.0 mL min?1. The following parameters were obtained: quantification limit (QL) – 3.74 µg L?1, preconcentration factor (PF) – 36, consumption index (CI) – 0.55 mL, concentration efficiency (CE) – 18 min?1, and sample throughput – 25 h?1. The precision of the procedure assessed in terms of repeatability for ten determinations was 5.6% and 2.5% for respective concentrations of 5.0 and 110.0 µg L?1. Moreover, the analytical curve was obtained in the range of 5.0–180.0 µg L?1 (r = 0.9973), and a 1.64-fold increase in the method sensitivity was observed when compared with the analytical curve constructed for the NIP (non-imprinted polymer), thus suggesting a synergistic effect of the Ni(II) ions and CTAB on the adsorption properties of the IIP. The practical application of the adsorbent was evaluated from an analysis of tap, mineral, lake and river water. Considering the results of addition and recovery experiments (90.2–100 %), the efficiency of this adsorbent can be ensured for the interference-free preconcentration of the Ni(II) ions. 相似文献
12.
13.
Hong Mei SUN* Mu Jie YANG Qi SHEN Department of Chemistry Chemical Engineering Suzhou University Suzhou Department of Polymer Science Engineering Zhejiang University Hangzhou 《中国化学快报》2001,(11)
Over the past few years, the utilization of late transition metal-based soluble complexes as styrene polymerization catalysts has received considerable attention1. Various systems have been explored. For example, cationic h3-allylnickel complexes alone2 or modified by P (III) ligands3 as well as a few other systems (e. g., cationic h3-benzylic nickel complexes4) are active homogeneous catalysts for the low molecular weight polymerization of styrene by simple cationic mechanism2,3,4. Neut… 相似文献
14.
Towards Norcorrin: Hydrogenation Chemistry and the Heterodimerization of Nickel(II) Norcorrole 下载免费PDF全文
Bin Liu Prof. Xiaofang Li Prof. Marcin Stępień Prof. Piotr J. Chmielewski 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(21):7790-7797
5,14‐Dimesitylnorcorrolatonickel(II) was hydrogenated under mild conditions (room temperature, 1 atm H2, THF solution, 5 min.) in the presence of Raney nickel to yield nonaromatic derivatives that were isolated and characterized by NMR spectroscopy, UV/Vis spectrophotometry, HRMS, cyclic voltammetry, and X‐ray diffraction analysis. The major hydrogenation product, 1,2,3,7,8,9‐hexahydronorcorrolatonickel(II), underwent dimerization in the presence of p‐chloranil to give a nonsymmetrically linked 2,3′‐bis(norcorrole) system that can adopt eight different oxidation states over a redox potential window of 3 V and has a HOMO–LUMO gap of 0.92 V. 相似文献
15.
Dzyaz'ko Yu. S. Rozhdestvenskaya L. M. Pal'chik A. V. Belyakov V. N. 《Theoretical and Experimental Chemistry》2003,39(6):380-384
The mobility of Ni(II) ions in inorganic ion exchangers based on zirconium hydroxophosphate with varying phosphorus content was studied using electromigration and kinetic methods. It was found that the effective diffusion coefficient of nickel in the ion exchanger phase increased with increasing phosphorus content within the range 1·10–13 to 2·10–12 m2/s. 相似文献
16.
Mn(II), Co(II), Ni(II) and Cu(II) chelates with3-phenyl-4-(p-methoxyphenylazo)-5-pyrazolone have been synthesized and were characterized by elemental and thermal analyses as well as
by IR, UV-VIS, 1HNMR, conductometric and magnetic measurements. The first stage in the thermal decomposition process of these complexes shows
the presence of water of hydration, the second denotes the removal of the coordinated water molecules. The final decomposition
products were found to be the respective metal oxides. The data of the investigated complexes suggest octahedral geometry
with respect to Co(II) 1:1, tetrahedral for Ni(II) 1:1and 2:3; square planar for Cu(II) 1:1 and 2:3; the complexes with no
coordinated water molecules (2:3) Co(II) and Mn(II) complexes are tetrahedral.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
17.
Sandeep Kumar Thakur Dr. Mandeep Kaur Dr. Krishna Kumar Manar Manu Adhikari Dr. Angshuman Roy Choudhury Dr. Sanjay Singh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(59):e202202237
Negishi cross-coupling reaction of organozinc compounds as nucleophiles with aryl halides has drawn immense focus for C−C bond formation reactions. In comparison to the well-established library of Pd complexes, the C−C cross-coupling of this particular approach is largely primitive with nickel-complexes. Herein, we describe the syntheses of Ni(II) complexes, [(MeBICAAC)2NiX2] (X=Cl ( 1 ), Br ( 2 ), and I ( 3 )) by employing the bicyclic (alkyl)(amino)carbene (MeBICAAC) ligand. The reduction of complexes 1 – 3 using KC8 afforded the two coordinate low valent, Ni(0) complex, [(MeBICAAC)2Ni(0)] ( 4 ). Complexes 1 – 4 have been characterized by spectroscopic techniques and their solid-state structures were also confirmed by X-ray crystallography. Furthermore, complexes 1 – 4 have been applied in a direct and convenient method to catalyze the Negishi cross-coupling reaction of various aryl halides with 2,6-difluorophenylzinc bromide or phenylzinc bromide as the coupling partner in the presence of 3 mol % catalyst. Comparatively, among all-pristine complexes, 1 exhibit high catalytic potential to afford value-added C−C coupled products without the use of any additive. The UV-vis studies and HRMS measurements of controlled stochiometric reactions vindicate the involvement of Ni(I)−NI(III) cycle featured with a penta-coordinated Ni(III)-aryl species as the key intermediate for 1 whereas Ni(0)/Ni(II) species are potentially involved in the catalytic cycle of 4 . 相似文献
18.
G. A. Kostin A. O. Borodin V. G. Torgov N. V. Kuratieva D. Yu. Naumov S. I. Miroshnichenko V. I. Kalchenko 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(1-2):45-52
Monomeric and polymeric 1:2 complexes of a novel calix[4]arene-tetraphosphineoxide with Co(II) or Ni(II) nitrates were synthesized
and analyzed by the X-ray method. In the monomeric complexes each metal cation is coordinated by two bidentate NO3-ligands as well as by two proximal P=O groups at the calixarene skeleton. In the nickel metallopolymer one sort of the cations
is bound by the two proximal P=O-groups but other cations link neighboring calixarene molecules through Р=О···Ni···O=P chains.
The complexes possess molecular cavities or channels filled by solvent molecules.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
Nina E. Wezynfeld Arkadiusz M. Bonna Dawid Ponka Wojciech Bal Tomasz Frczyk 《Molecules (Basel, Switzerland)》2022,27(17)
Nickel is toxic to humans. Its compounds are carcinogenic. Furthermore, nickel allergy is a severe health problem that affects approximately 10–20% of humans. The mechanism by which these conditions develop remains unclear, but it may involve the cleavage of specific proteins by nickel ions. Ni(II) ions cleave the peptide bond preceding the Ser/Thr-Xaa-His sequence. Such sequences are present in all four enzymes of the melatonin biosynthesis pathway, i.e., tryptophan 5-hydroxylase 1, aromatic-l-amino-acid decarboxylase, serotonin N-acetyltransferase, and acetylserotonin O-methyltransferase. Moreover, fragments prone to Ni(II) are exposed on surfaces of these proteins. Our results indicate that all four studied fragments undergo cleavage within tens of hours at pH 8.2 and 37 °C, corresponding with the conditions in the mitochondrial matrix. Since melatonin, a potent antioxidant and anti-inflammatory agent, is synthesized within the mitochondria of virtually all human cells, depleting its supply may be detrimental, e.g., by raising the oxidative stress level. Intriguingly, Ni(II) ions have been shown to mimic hypoxia through the stabilization of HIF-1α protein, but melatonin prevents the action of HIF-1α. Considering all this, the enzymes of the melatonin biosynthesis pathway seem to be a toxicological target for Ni(II) ions. 相似文献
20.
基于一种新的电极制作方法, 研制了具有薄层色谱分离功能的一次性薄层色谱电极. 结合该电极的分离、保留分析物于电极表面一定空间区域的色谱分离能力与电极表面电化学发光信号的空间分辨能力, 实现了分析物的高效分离与原位高灵敏度电化学发光(ECL)检测, 建立了电化学发光分析方法与薄层色谱分离方法联用的新技术. 并以Ni2+离子为代表探讨了这一方法的可行性和分析特性. 在最佳的实验条件下, 该方法测定Ni2+离子的线性范围为5.0× 10-9~5.0×10-6 g/mL, 检出限为1.5×10-9 g/mL, 相对标准偏差为2.8% (c=1.0×10-6 g/mL, n=11). 相似文献