首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
《中国化学会会志》2017,64(11):1294-1302
In this work, a nickel(II) synergist complex with methyl isonicotinate (BI, a short chain analog of n‐hexyl 3‐pyridinecarboxylate ester) and naphthalene‐2‐sulfonic acid (HNS, a short chain analog of dinonylnaphthalene sulfonic acid) was synthesized and studied by single‐crystal X‐ray diffraction. The nickel(II) complex crystallizes in the monoclinic P 21/n space group with the composition [Ni(H2O)4(BI)2](NS)2·2H2O. The Ni(II) ions of these crystallographically independent molecules lie on an inversion center, forming a trans‐form distorted octahedral coordination structure. The nickel(II) ions can coordinate with four water molecules and two BI ligands, resulting in a mono‐metallic structure [Ni(H2O)4(BI)2]2+. There is no direct interaction between nickel(II) and sulfonic oxygen atoms of the sulfonate anions, but hydrogen bonds form between sulfonic oxygen atoms and water molecules in the synergist complex. In order to further elucidate the solution structure of the nickel(II) complexes with the actual synergistic mixture containing n‐hexyl 3‐pyridinecarboxylate ester and dinonylnaphthalene sulfonic acid in the nonpolar organic phase, the nickel(II) complexes were studied by electrospray ionization mass spectrometry. The results indicated that the extracted nickel(II) complexes in the nonpolar solvent have a similar coordination structure as that of the crystalline nickel(II) synergist complex.  相似文献   

2.
Bis(N-alkyldithiocarbamato)nickel(II) complexes (1–5) [Ni(S2CNHR)2] (where R?=?Me, Et, n-Pr, i-Pr, n-Bu) were synthesized by the reaction of NiCl2?·?6H2O and the corresponding sodium salt of N-alkyldithiocarbamate in 1?:?2 molar ratio in aqueous medium. These bis(N-alkyldithiocarbamato)nickel(II) complexes (1–5) were characterized by elemental analysis, UV-Visible, IR, and 1H/13C-NMR spectroscopy. The crystallographic investigation of [Ni(S2CNH(n-Pr))2] (3) and [Ni(S2CNH(i-Pr))2] (4) revealed distorted square-planar geometry around nickel(II). The dithiocarbamates have anisobidentate coordination with nickel and the dithiocarbamates are trans.  相似文献   

3.
Abstract

Nickel(II) complexes with a combination of trithiocyanuric acid and diamines or triamines of composition [Ni(aepa)(ttcH)(H2O)], [Ni(dien)(ttcH)(H2O)], [Ni(dpta)(ttcH)(H2O)] H2O, [Ni(phen)2(ttcH)]H2O, [Ni(phen)3](ttcH)-5H2O and [Ni(1,2-pn)3](ttcH)-H2O (aepa = N-(2-aminoethyl)-1,3-propanediamine,dien = diethylenetriamine,dpta = dipropylenetnamine, phen = 1,10-phenanthroline, 1,2-pn = 1,2-diaminopropane. ttcH3 = trithiocyanuric acid) have been prepared. The compounds have been characterized by means of elemental analysis, IR and electronic spectroscopies and magnetochemical measurements. Selected complexes were studied by thermal analysis. The compounds can be characterized as distorted octahedral Ni(II) complexes. It was found that the trithiocyanuric dianion can act either as a bidentate ligand or be situated out of the coordination sphere of nickel. The crystal and molecular structure of [Ni(dpta)(ttcH)(H2O)] H2O was determined. Crystals are monoclinic, space group P21/n, with a = 20.316(4), b = 7.967(2), c = 21.401(4) Å, β = 99.23(3)°, K=3419.1(13)Å3, Z = 4, T = 293 K. The nickel(II) atom is six-coordinated by three nitrogen atoms from dipropylene-triamine, nitrogen and sulphur from trithiocyanuric acid, and an oxygen atom from a water molecule in a distorted octahedral geometry.  相似文献   

4.
Neutral heterotetranuclear complex Co3Fe(mp)4(Hmp)(PBun3)3 2 (PBun3 = tri-n-butylphosphine) of 2-mercaptophenol (H2mp) was synthesized in a molar ratio of CoCl2:FeCl3:H2mp:NaOMe:PBun3 = 0.75:0.25:1:2:1 under anaerobic conditions. It represents partially FeIII-substituted form of the asymmetric mixed-valence tetracobalt complex Co4(mp)4(Hmp)(PBun3)3 (1). 2 crystallizes in the triclinic space group Pl?, with a = 12.373(2) Å, b = 15.677(3) Å, c = 20.571(4) Å, α = 93.59(3)° β = 93.45(3)° γ = 112.30(3)°, V = 3669 Å3, and Z = 2. The molecule exhibits a cyclic skeleton of Co3FeS4O3 with two doubly μ2-S bridges, one doubly μ2-O bridge, and one singly μ2-O bridge. The four mp2? ligands display two different modes, ObSb-T and OtSb, while the monoanion Hmp? is only terminally chelated to Fe3+ ion in HOtSt fashion (b stands for bridge, t for terminal, and T for trinuclear). The three Co centers are located in approximately square-based pyramidal environments, and the Fe atom in distorted trigonal bipyramidal geometry. Three types of main fragment ions were observed in the FAB mass spectrum of 2. The dissociation of the fragments follows the order: PBun3 first, then Hmp and mp ligands. Moreover, the dissociation of Fe(Hmp) is first, followed by Co(mp) and Co(mp)2, according with the fact that Fe(Hmp) is only loosely bonded. Variable-temperature magnetic susceptibility measurements showed that 2 exhibits weak magnetic exchange interactions.  相似文献   

5.
Abstract

Six new nickel complexes of two dithiocarbamate ligands (cyfdtc = N-cyclohexyl-N- furfuryldithiocarbamate and bztpedtc = N-benzyl-N-[2-thiophenylethyl]dithiocarbamate) namely, (Ni[cyfdtc]2) (1), (Ni[bztpedtc]2) (2), (Ni[cyfdtc][NCS][PPh3]) (3), (Ni[bztpedtc] [NCS][PPh3]) (4), (Ni[cyfdtc][PPh3]2)ClO4 (5), and (Ni[bztpedtc][PPh3]2)ClO4 (6) have been prepared and characterized using IR, electronic, and NMR (1H and 13C) spectra. A single crystal X-ray structural analysis was carried out for complex 3 and showed that nickel is in a distorted square planar arrangement with the NiS2PN chromophore. The shift in νC?N of the heteroleptic complexes to higher frequencies compared with the parent complex is assigned to mesomeric delocalization of electron density from the

dithiocarbamate ligand toward the metal atom, which increases the contribution of polar thioureide form in mixed ligand complexes. Electronic spectral studies suggest square planar geometry for the complexes. In the 13C NMR spectra, the upfield shift of NCS2 carbon signal for 3 and 4 from the chemical shift value of 1 and 2 is due to effect of PPh3 on the mesomeric drift of electron density toward nickel throughout thioureide C?N bond.  相似文献   

6.
In this article, we present the results of the speciation of the binary nickel(II)-oxalic acid (H2L) and nickel(II)-malonic acid (H2L) systems studied by electromotive forces measurements emf (H) using 1.0?mol?dm?3 NaCl as the ionic medium at 25°C. The experimental data were analyzed by a computational least-squares program LETAGROP/FONDO, a version of the LETAGROP program, written to analyze regular formation function and reduced formation functions, taking into account the hydrolysis of the nickel(II) cation and the acid base reactions of the ligands which were kept fixed during the analysis. In the nickel(II)-oxalic acid system the complexes [NiHL]+, [NiL], [Ni(OH)L]?, and [NiL2]2? were observed and for the nickel(II)-malonic acid system the complexes [NiHL]+, [NiL], [Ni(OH)L]?, and [Ni(OH)2L]2? were detected. The stability constants were determined and the species distribution diagrams as a function of pH are briefly discussed.  相似文献   

7.
Twelve new nickel(II) complexes of functionalized dithiocarabamates [Ni(S2CNRR')2](1-6) and [Ni(S2CNRR')(NCS)(PPh3)](7-12) [where R=furfuryl; R'=2-hydroxy benzyl (1,7), 3-hydroxy benzyl (2,8), 4-hydroxy benzyl (3,9), 4-methoxy benzyl (4,10), 4-fluoro benzyl (5,11), 4-chloro benzyl (6,12)] have been prepared and characterized by elemental analysis, IR, UV-Vis and NMR (1H and 13C) spectroscopy. IR spectra of the complexes support the bidentate coordination of dithiocarbamate ligands. Electronic spectral studies on complexes 1-12 indicate square planar geometry around the nickel(II) central atom. In the 13C NMR spectra, the upfield shift of NCS2 carbon signal for heteroleptic complex (7-12) compared to homoleptic complexes (1-6) is due to the effect of PPh3 on the mesomeric drift of electron density toward nickel through thioureide C-N bond. Single crystal X-ray structural analysis of complex 11 confirms that the coordination geometry about the Ni(II) is distorted square planar. A rare intramolecular anagostic interaction C–HNi [Ni???H=2.804 Å] is observed. The packing of complex 11 is stabilized by non-conventional C–HS, C–H?F and C–H?π(chelate, NiS2C) bonding interactions.  相似文献   

8.
Three complexes of a dithiocarbamate ligand (dbpdtc = benzyl(4-(benzylamino)phenyl)dithiocarbamate), namely [Ni(dbpdtc)2] (1), [Ni(dbpdtc)(NCS)(PPh3)] (2) and [Ni(dbpdtc)(PPh3)2]ClO4 (3) have been prepared. The complexes were characterized by IR, electronic spectroscopy and cyclic voltammetry. A single-crystal X-ray structural analysis was carried out for complex 1 and showed that the nickel is in a distorted square planar environment with a NiS4 chromophore. For the two mixed ligand complexes, the thioureide ν C–N values were shifted to higher wavenumbers compared to [Ni(dbpdtc)2], suggesting increased strength of the thioureide bond due to the presence of the π-accepting phosphine. Electronic spectral studies suggest square planar geometries for the complexes. Cyclic voltammetry showed easier reduction of nickel(II) to nickel(I) in the mixed ligand complexes compared to [Ni(dbpdtc)2].  相似文献   

9.
Four new complexes of 2,3,4-trimethoxybenzoic acid anion with manganese(II), cobalt(II), nickel(II) and copper(II) cations were synthesized, analysed and characterized by standard chemical and physical methods. 2,3,4-Trimethoxybenzoates of Mn(II), Co(II), Ni(II) and Cu(II) are polycrystalline compounds with colours typical for M(II) ions. The carboxylate group in the anhydrous complexes of Mn(II), Co(II) and Ni(II) is monodentate and in that of Cu(II) monohydrate is bidentate bridging one. The anhydrous complexes of Mn(II), Co(II) and Ni(II) heated in air to 1273 K are stable up to 505–517 K. Next in the range of 505–1205 K they decompose to the following oxides: Mn3O4, CoO, NiO. The complex of Cu(II) is stable up to 390 K, and next in the range of 390–443 K it loses one molecule of water. The final product of its decomposition is CuO. The solubility in water at 293 K is of the order of 10–3 mol dm–3 for the Mn(II) complex and 10–4 mol dm–3 for Co(II), Ni(II) and Cu(II) complexes. The magnetic moment values of Mn2+, Co2+, Ni2+ and Cu2+ ions in 2,3,4-trimethoxybenzoates experimentally determined in the range of 77–300 K change from 5.64–6.57 μB (for Mn2+), 4.73–5.17 μB (for Co2+), 3.26–3.35 μB (for Ni2+) and 0.27–1.42 μB (for Cu2+). 2,3,4-Trimethoxybenzoates of Mn(II), Co(II) and Ni(II) follow the Curie–Weiss law, whereas that of Cu(II) forms a dimer.  相似文献   

10.
A new series of nickel(II) complexes derived from symmetrical diacetyl bisaroylhydrazones [Ni(L1-R)] and unsymmetric phenylglyoxal bisaroylhydrazones [Ni(L2-R)] have been prepared and characterized. X-ray crystal and molecular structures of [Ni(L1-H)], [Ni(L1-pCH3O)] and [Ni(L1-pNO2)] have been determined. In these complexes, the Ni(II) is in a distorted square planar environment and the aroylhydrazone acts as dinegative tetradentate ligand forming a 5,5,5-tricyclic chelate ring. Reaction of [Ni(L1-R)] with aqueous ammonia afforded the paramagnetic five coordinate [Ni(L1-R)(NH3)] while [Ni(L2-R)] gave the diamagnetic square planar [Ni(L2-R)(NH3)] complexes. Reaction of [Ni(L1-R)] complexes with imidazole gave the corresponding paramagnetic octahedral bis(imidazole) adducts. X-ray structures of both [Ni(L1-H)(HIm)2] and [Ni(L1-pNO2)(HIm)2] suggest a distorted octahedral structure where the bisaroylhydrazone occupies the basal plane while the two imidazoles occupy the axial sites. The molecular units are associated together forming triple stranded helical chains. With imidazole the [Ni(L2-R)] series gave the corresponding diamagnetic mono(imidazole) [Ni(L2-R)(HIm)] complexes, The X-ray structure of {Ni(L2-pCH3)(HIm)] suggest square planar arrangement around the Ni(II) where the bisaroylhydrazone acts as dinegative NNO tridentate ligand forming with the Ni(II) a 5,6-bicyclic chelate ring the fourth coordination site is occupied by imidazole nitrogen.  相似文献   

11.
Thermal decomposition of Ni(II), Pd(II), and Pt(II) complexes of N-pyrimidin-2ylthiourea (AllPmTu) have been studied by TG, DTG, and DTA and by electron impact (EI) mass spectra. The complexes have the molecular formulae as [Ni(AllPmTu)Cl2(H2O)], [Ni(AllPmTu)2Cl2(H2O)2], and [M(AllPmTu)Cl2], where M = PdII or PtII, and [Pt(AllPmTu)2]. The TG curves show that Ni(II) complexes decompose in three stages to yield NiO as a residue, while Pd(II) and Pt(II) decompose in two stages to yield MS residues. The initial mass losses correspond to elimination of allylamine for Pd(II) and Pt(II) complexes but, allyisothiocyanate for both Ni(II) complexes revealing that sulfur atom of thiourea part is involved in coordination to Pd(II) and Pt(II) but does not to Ni(II). Kinetic parameters (E #, n, ΔH #, ΔS #, ΔG #) of the decomposition stages are determined and correlated with bonding and structural properties of the complexes. The EI mass spectra of the complexes show fragments corresponding to the evolved and intermediate species.  相似文献   

12.
Nickel(0)-olefine π-complexes such as Ni(C2H4)3 and Ni(C2H4)(PR3)2 [6] prepared by conventional ligand replacement reaction are diamagnetic and stable up to room temperature. Similar π-complexes e.g. Ni(C2H4) n (withn = 1, 2 or 3) generated by cryo-condensation technique [3] may exist in a paramagnetic state which derives from the triplet ground state of the atomic nickel. The stability of (η2-ethylene) nickel has been explained byab initio-MO calculations relating the energies of the complexes to different terms (1 S and3 F) of the nickel atom.
  相似文献   

13.
New bidentate Schiff-base ligands 2-(2,4-di-p-tolyl-3-azabicyclo[3.3.1]nonan-9-ylidene)hydrazinecarbothioamide HL1 and 2-(2,4-di-p-tolyl-3-azabicyclo[3.3.1]nonan-9-ylidene)hydrazinecarboxamide HL2 were synthesized from the condensation of 2,4-di-p-tolyl-3-azabicyclo[3.3.1]nonan-9-one with thiosemicarbazide and semicarbazide, respectively. Homoleptic complexes of these ligands, of general formula K[Cr(L n )2Cl2], K2[Mn(L n )2Cl2], K2[Fe(L1)2Cl2] and [M(L n )2] (where M = Co(II), Ni(II) Cu(II), Zn(II), Cd(II), and Hg(II) ions; n = 1 or 2) are reported. The mode of bonding and overall geometry of the complexes were determined through IR, UV-Vis, NMR and mass spectral studies, magnetic moment measurements, elemental analysis, metal content, and conductance. These studies revealed octahedral geometry for Cr(III), Mn(II), and Fe(II) complexes, square planar for Cu(II), Co(II), and Ni(II) complexes and tetrahedral for Zn(II), Cd(II), and Hg(II) complexes.  相似文献   

14.
Reactions between nickel(II) and copper(II) salts [M(L) n ](ClO4)2 [L: 2-(pyrazole-1-ylmethyl)pyridine; n = 3 for Ni(II) and n = 2 for Ni(II) and Cu(II)] and LiTCNQ or mixture of LiTCNQ/TCNQ and Et3NH(TCNQ)2 yielded [Ni(L)3](TCNQ)2 · H2O, [Ni(L)2(TCNQ)2], [Ni(L)3](TCNQ)3, [Ni(L)2(TCNQ)3], and [Cu(L)2(TCNQ)3] · 3H2O. These complexes were characterized by infrared, electronic absorption, variable temperature magnetic moments and electron paramagnetic studies. Magnetic moments increase with increase in temperature attributed to contribution from TCNQ, which has also been examined by electron paramagnetic resonance.  相似文献   

15.
《Polyhedron》1999,18(26):3383-3390
Nickel(II) complexes of 1,6-bis(pyridyl)-2,5-dithiahexane (L1), 1,7-bis(2′-pyridyl)-2,6-dithiaheptane (L2) and 1,9-bis(2′-pyridyl)-2,5,8-trithianonane (L3) have been prepared and their spectroscopic and redox behaviors were studied. [Ni(II)L1(H2O)2](ClO4)2, and [Ni(II)L3(H2O)](ClO4)2 were crystallized in single crystal form; their structures were solved by X-ray crystallography. The structures of the complexes are of distorted octahedral geometry. A red shift in the electronic spectra and a positive potential shift in electrochemical studies were detected during the addition of the sodium salt of 2-mercaptoethanesulfonic acid (CoM) to Ni(II) complexes containing L1 and L2. The high redox potential shifting difference (PSD) was observed with the addition of CoM to [NiL1]2+, which accounts for the axial coordination of CoM with the nickel ion. However, [Ni(II)L3]2+ does not respond well with CoM addition due to the structural limitation around the Ni(II) ion. A destabilization of [Ni(II)L1]2+ and [Ni(II)L2]2+ complexes and stabilization for [Ni(II)L3]2+ were noticed in their redox studies and these trends were inversely changed during anaerobic CoM addition to Ni(II) complexes. A nephelauxetic effect (β values) has been shown to establish a good relation with PSD.  相似文献   

16.
Two new N2O2 unsymmetrical Schiff bases, H2L1 = 3-[({o-[(E)-(o-hydroxyphenyl)methylideneamino]phenyl}methyl)imino]-1-phenyl-1-buten-1-ol and H2L2 = 3-[({o-[(E)-(2-hydroxy-1-naphthyl)methylideneamino]phenyl}methyl)imino]-1-phenyl-1-buten-1-ol, and their copper(II) and nickel(II) complexes, [CuL1] (1), [CuL2] (2), [NiL1] (3), and [NiL2] (4), have been synthesized and characterized by elemental analyses and spectroscopic methods. The crystal structures of these complexes have been determined by X-ray diffraction. The coordination geometry around Cu(II) and Ni(II) centers is described as distorted square planar in all complexes with the CuN2O2 coordination more distorted than the Ni ones. The electrochemical studies of these complexes indicate a good correlation between the structural distortion and the redox potentials of the metal centers. The ligand and metal complexes were also screened for their in vitro antibacterial activity.  相似文献   

17.
A new vic-dioxime ligand, N,N′-bis(aminopyreneglyoxime) (LH2), and its copper(II), nickel(II) and cobalt(II) metal complexes were synthesized and characterized by elemental analyses, IR, UVVIS and 1H and 13C NMR spectra (for the ligand). Mononuclear complexes were synthesized by a reaction of ligand (LH2) and salts of Co(II), Ni(II), and Cu(II) in ethanol. The complexes have the metal-ligand ratio of 1: 2 and metals are coordinated by N,N′ atoms of vicinal dioximes. The ligand acts in a polydentate fashion bending through nitrogen atoms in the presence of a base, as do most vic-dioximes. Detection of a H-bonding in the Co(II), Ni(II), and Cu(II) complexes by IR revealed the square-planar MN4 coordination of mononuclear complexes. Fluorescent properties of the ligand and its complexes arise from pyrene units conjugated with a vic-dioxime moiety. Fluorescence emission spectra of the ligand showed a drastic decrease in its fluorescence intensity upon metal binding. The electrochemical properties of the complexes were studied by the cyclic voltammetry technique. The nickel complex displayed an irreversible oxidation process while the copper complex exhibited a quasi-reversible oxidation and reduction processes based on the copper Cu(II)/Cu(III) and Cu(II)/Cu(I) couples, respectively.  相似文献   

18.
Two sets of nickel(II) complexes of a series of tetradentate NSNO ligands were synthesized and isolated in their pure form. All these complexes, formulated as [Ni(L)Cl]2 and [Ni(L)(N3)]2 [HL = pyridylthioazophenols], were characterized using physicochemical and spectroscopic tools. The solid-state structures of two complexes (1a and 2a) were established by X-ray crystallography. The geometry about the nickel ion of the complexes is octahedral and the complexes are dimeric in nature. In 1, two Ni(II) ions are bridged by two Cl anions while in 2 they are bridged by two azide ions in a μ-1,1-bridging fashion.  相似文献   

19.
Schiff-base complexes [ML(H2O)2(Ac)]nH2O (M?=?Co(II), Ni(II) and Zn(II); L?=?Schiff-base ligand derived from 2-acetylpyridine and alanine and n?=?1–3/2) were synthesized and characterized by elemental analysis, spectral (FTIR, UV/Vis, MS, 1H-NMR), thermal (TGA), conductance and magnetic moment measurements. The results suggest octahedral geometry for all the isolated complexes. IR spectra show that the ligand coordinates to the metal ions as mononegative tridentate through pyridyl nitrogen, azomethine nitrogen and carboxylate oxygen after deprotonation of the hydroxyl group. Semi-empirical calculations PM3 and AM1 have been used to study the molecular geometry and the harmonic vibrational spectra to assist the experimental assignments of the complexes.  相似文献   

20.
Monometallic zinc(II) and nickel(II) complexes, [Zn(H2nsh)(H2O)] (1) and [Ni(H2nsh)(H2O)2] (2), have been synthesized in methanol by template method from bis(2-hydroxy-1-naphthaldehyde)succinoyldihydrazone (H4nsh). Reaction of monometallic complexes with alternate metal(II) acetates as a transmetallator in 1 : 3 molar ratio resulted in the formation of heterobimetallic complexes [NiZn(nsh)(A)3] and [ZnNi(nsh)(A′)2] (A = H2O (3), py (4), 2-pic (5), 3-pic (6), 4-pic (7)), (A′ = H2O (8), py (9), 2-pic (10), 3-pic (11), and 4-pic (12)). The complexes have been characterized by elemental analyzes, mass spectra, molar conductance, magnetic moments, electronic, EPR, and IR spectroscopies. All of the complexes are non-electrolytes. Monometallic zinc(II) is diamagnetic while monometallic nickel(II) complex and all heterobimetallic complexes are paramagnetic. The metal centers in heterobimetallic complexes are tethered by dihydrazone and naphthoxo bridging. Zinc(II) is square pyramidal; nickel(II) is six-coordinate distorted octahedral except [ZnNi(nsh)(A)2], in which nickel(II) has square-pyramidal geometry. The displacement of metal center in monometallic complexes by metal ion has been observed in the resulting heterobimetallic complexes.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号