Mixed Ligand Nickel Research Articles

Synthesis and Crystal Structure of Mixed-Ligand Ni(II) Complex of N-(1-Phenyl-3-methyl-4-benzylidene-5-pyrazolone) p-Nitrobezoylhydrazide and Pyridine

A novel mixed-ligand nickel complex, [Ni(PMBP—PNH) (Py)3], [PMBP—PNH=N-(1-phenyl-3-methyl-4-benzylidene-5-pyrazolone) p-nitrobezoylhydrazide; Py = pyridine], has been synthesized by the hydrothermal method and characterized by elemental analysis, IR spectrum, thermal analysis, and single-crystal X-ray diffraction. The X-ray diffraction reveals that the nickel (II) ion in the title complex is in a slightly distorted octahedral arrangement of the ONO donor atoms of primary ligand PMBP-PNH and three N-donor atoms in the secondary ligand pyridine.

The unexpected tridentate role of the tripodal ligand N-(carbamoylmethyl)iminodiacetato(2−) (ADA) in a new mixed-ligand nickel(II) complex with 2,2 ′-bipyridine (bipy) as secondary ligand: structure of [Ni(ADA)(bipy)(H 2O)]·4H 2O

The crystal structure of a new mixed-ligand nickel(II) complex of N-(carbamoylmethyl)iminodiacetato(2−) (ADA) and 2,2 ′-bipyridine (bipy), with formula [Ni(ADA)(bipy)(H 2O)]·4H 2O (compound 3), reveals an unexpected tridentate ADA ligand, with a free N-(2-amidomethyl) arm, in contrast with all other known structures of metal–ADA chelates which have ADA 2− as tripodal–tetradentate ligand. This finding is explained on the basis of a structural comparison with the compounds of [Ni(ADA)(H 2O) 2] (1) and [ Ni( ADA)( Him )( H 2 O)]·1.5 H 2 O (2, Him = imidazole) which reveals significant changes in Ni–N(amino tertiary) and Ni–O(amide) bond lengths as well as in the ADA denticity and ligand conformation concerning the iminodiacetato(2−) moiety (IDA) in these Ni(II) chelates. The ADA-ligand conformation is mer-IDA + O(amide), fac-IDA + O(amide) or only fac-IDA-tridentate in 1, 2 or 3 respectively.

Extraction of Unprotected Amino Acids by Mixed-Ligand Nickel(II) and Copper(II) Chelates

Extraction of Unprotected Amino Acids by Mixed-Ligand Nickel(II) and Copper(II) Chelates

Synthesis and spectroscopic investigation of some mixed-ligand nickel(II) chelates containing phosphines and 1,1-dithiolate ligands. Crystal structure of [(1,2-bis(diphenylphosphino)ethane)-1,1-dicyano-2,2-ethylenedithiolato]nickel(II)

In a sequence to our earlier reports of transition metal complexes with dithiolate and diamine ligands, we here report the isolation of nickel(II) mixed-ligand complexes containing dithiolates and phosphine derivatives as ligands and their characterization by chemical analysis, as well as magnetic and spectral studies. These complexes are mononuclear, neutral compounds, diamagnetic in nature in the solid state assuming thus a planar geometry of the chromophore. An X-ray diffraction study performed on one member of the series, namely the [(1,2-bis(diphenylphosphino)ethane)1,1-dicyano-2,2-ethylenedithiolato]nickel(II) complex confirmed this geometry. In this compound there are two molecules in the asymmetric unit of the structure. Nickel(II) is four coordinated with the two sulfur atoms from the 1,1-dicyano-2,2-ethylenedithiolate (i-MNT) ligand [NiS distance range: 2.206(1)–2.211(1) Å] and the two phosphorous atoms from the 1,2-bis(diphenylphosphino)ethane(dppe) ligand [NiP distance range: 2.149(1)–2.168(1) Å].

Synthesis, Magnetic Properties, and Electronic Spectra of Octahedral Mixed-Ligand (β-Diketonato)nickel(II) Complexes with a Chelated Nitronyl Nitroxide Radical.

Synthesis, Magnetic Properties, and Electronic Spectra of Octahedral Mixed-Ligand (β-Diketonato)nickel(II) Complexes with a Chelated Nitronyl Nitroxide Radical.

Synthesis, Magnetic Properties, and Electronic Spectra of Octahedral Mixed-Ligand (β-Diketonato)nickel(II) Complexes with a Chelated Nitronyl Nitroxide Radical

Two series of new mixed-ligand nitronyl nitroxide Ni(II) complexes of [Ni(beta-diketonato)(2)(NIT2-py)] and [Ni(beta-diketonato)(tmen)(NIT2-py)](+) types with various kinds of beta-diketonates have been synthesized and structurally and magnetically characterized, where NIT2-py is 2-(2-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl 3-oxide and tmen is N,N,N ',N '-tetramethylethylenediamine. The X-ray structural analysis for three tmen complexes with 2,4-pentanedionate (1b), 1,3-diphenyl-1,3-propanedionate (2b), and 4,4,4-trifluoro-1-phenyl-1,3-butanedionate (5b) demonstrated that the beta-diketonato complexes assume a mer (cis,trans) N(3)O(3) geometrical configuration. The structural parameters are as follows: 1b (C(23)H(39)F(6)N(5)NiPO(4).(1)/(3)CH(2)Cl(2)), trigonal, R&thremacr;, a = 33.299(5) Å, c = 15.007(9) Å, Z = 18; 2b (C(28)H(41)F(6)N(5)NiPO(4)), orthorhombic, Pbca, a = 23.732(6) Å, b = 18.504(5) Å, c = 15.345(4) Å, Z = 8; 5b (C(28)H(38)F(9)N(5)NiPO(4)), triclinic, P&onemacr;, a = 12.068(2) Å, b = 16.942(2) Å, c = 9.161(1) Å, alpha = 105.26(1) degrees, beta = 103.72(1) degrees, gamma = 71.62(1) degrees, Z = 2. The antiferromagnetic interactions between Ni(II) and NIT2-py were found within ranges of J = -207 to -224 cm(-)(1) for the bis(beta-diketonato) complexes and of J = -35 to -150 cm(-)(1) for the (beta-diketonato)(tmen) complexes. The displacement of the beta-diketonates with tmen in bis(beta-diketonato) complexes decreases the J values, and the effect of the 1,3-substituents in the beta-diketonates on the J values is observed in a systematic manner for all the bis(beta-diketonato) complexes and for the (methyl- and phenyl-substituted-beta-diketonato)(tmen) complexes but not for the trifluoromethyl-substituted complex. The room-temperature electronic spectra of the bis(beta-diketonato) and the (beta-diketonato)(tmen) complexes exhibit enhanced spin-forbidden d-d transitions at 13.0 x 10(3) cm(-)(1) and new metal-ligand charge-transfer (MLCT) transitions around (16.0-19.0) x 10(3) cm(-)(1). The variation of the spectroscopic characteristics with modification of the beta-diketonato ligands is discussed through the exchange mechanism in connection with the antiferromagnetic interactions in terms of the substituent effects or the Hammett sigma(m) constants.

Synthesis and Characterization of Mixed-Ligand Nickel(II) Chelates of β-Diones and α-Diimines. Crystal and Molecular Structure of [Ni(ncup)2Etacet]ClO4

Synthesis and Characterization of Mixed-Ligand Nickel(II) Chelates of β-Diones and α-Diimines. Crystal and Molecular Structure of [Ni(ncup)2Etacet]ClO4

Preparation and spectral study of mixed-ligand nickel (II) chelates containing N- or N,N′-methylated ethylenediamines and tropolonate or hinokitiolate ligands

Eleven mixed-ligand chelates of Ni (II) containing a molecule of N,N-di-, N,N,N′-tri-, or N,N,N′,N′-tetramethylethylenediamine, and a tropolonate (trop) or hinokitiolate (hino) ligand, were prepared, and their electronic spectra in solid state and in various organic solvents were studied. Most systems studied were green, containing octahedral chelate species [Ni (trop\\hino) (diamine) (H2O\\Solvent) 2] + or [Ni (NO3) (trop\\hino) (diamine) ] , but some were red, containing square planar [Ni (trop\\hino) (diamine) ] +, and an equilibrium between the octahedral and square planar species was sometimes observed in solutions. Strong spectral resemblances with the corresponding diamine-β-diketonate chelates of Ni (II) could be pointed out.

Influence of conjugated nitrogenous bases on the spectra and structure of mixed-ligand nickel(II) chelates containing β-diones

The infrared and electronic excitation spectra of a series of new nickel(II) chelates containing anα-diimine (or nitrogenous base, enR) and the anion of aΒ-dione (1,3-ketoenol or 1,3-ketoester,ΒH) were obtained in the solid state and in solution. The composition and the overall structure of the new chelates in the solid state depends on ligand concentration, the substituents within theΒ-dionato moiety and the counterion present. The IR and electronic excitation spectra of [Ni(enR)2Β]NO3 and [Ni(enR)Β(O2NO)] indicate, in conjunction with other physicochemical measurements, bidentate coordination of the ligands, while the spectral shifts reveal replacement of the (O,O′)nitrato group by basic solvents. The existence of the nickel(II) in an octahedral environment is confirmed by an X-ray structure analysis of [Ni(dpamH)2acac]NO3 · CH3OH (monoclinic, space groupP2l/n, a=17.296(1),b=7.462(1),c=21.604(3) a,Β=95.65(1)‡,Z=4, R=0.0534,Rw=0.0600), where dpamH denotes the 2,2′-dipyridylamine.

Co-ordination of solvent molecules to square-planar mixed-ligand nickel(II) complexes: a thermodynamic and quantum-mechanical study

Equilibria between four-, five- and six-co-ordinated substituted and unsubstituted [Ni(β-dik)(diam)]+ complexes associated with various solvents like acetonitrile, acetone, n-butanol, formamide dimethylformamide, dimethyl sulfoxide and pyridine have been investigated in nitroethane solution at 293 K. Increasing donor strength of the donor solvents (L) as well as increasing electron-withdrawing properties of the substituents at the β-diketonate (β-dik) and the diamine (diam) ligands favours the formation of six-co-ordinated species. The results are interpreted using correlations with IR, Hammett and electrochemical data, and results of semiempirical quantum-mechanical calculations carried out within an extended CNDO/2 framework, cis–trans Isomerism is proposed for [Ni(β-dik)(diam)L2]+ due to the mechanism of stepwise co-ordination.

Novel mixed-ligand derivatives ofbis(acetylacetonato)-bis(methylacetoacetato) andbis(ethylacetoacetate)-nickel(II) with some potentially mono-, bi- and tri-dentate 2/3-pyrazoline-5-ones

Novel mixed-ligand nickel(II) complexes having octahedral stereochemistry and general formula [Ni-(acac)2(L)2]/[Ni(meacac)2(L)2]/[Ni(etacac)2(L)2] (where L=3-methyl-1-phenyl-2-pyrazoline-5-one, 2,3-dimethyl-4-methylaminomethanesulphonate sodium monohydrate-1-phenyl-3-pyrazoline-5-one or 4-amino-2,3-dimethyl-1-phenyl-3-pyrazoline-5-one) have been isolated by reacting [Ni(acac)2(H2O)2]/[Ni(meacac)2(H2O)2]/ [Ni(etacac)2(H2O)2] with L in alcohol. The derivatives have been characterized by analytical data, molar conductances, magnetic measurements, electronic and i.r. spectra.

Mixed-ligand nickel(II) complexes of 2,2′-bipyridine and 1,10-phenanthroline with 3,4-dimercaptotoluene as quenchers of 1O 2

Mixed-ligand complexes of nickel(II) with 2,2′-bipyridine (bipy) and 3,4-dimercaptotoluene (DMT) and with 1,10-phenanthroline (phen) and 3,4-dimercaptotoluene were prepared and characterized. These complexes give sharp 1H nuclear magnetic resonance (NMR) spectra in dimethyl- d 6-sulphoxide which suggests that they are diamagnetic and square planar. They show five absorption bands in the region 250 – 600 nm. One of these bands shows a bathochromic shift of about 50 nm when the solvent is changed from CH 3OH to CHCl 3. They also act as physical quenchers of the photo-oxidation of 2,2,6,6-tetramethyl-4-piperidinol sensitized by haemotoporphyrin IX with quenching rate constants of 6.8 × 10 9 and 1.1 × 10 10 M −1 s −1 for [Ni(bipy)(DMT)] and [Ni(phen)(DMT)] respectively. These values approach the quenching rate constant (1.1 × 10 10 M −1 s −1 of a diamagnetic square planar complex of bis(di- n-butyldithiocarbamato)nickel-(II) which is a singlet molecular oxygen quencher.

The coordination chemistry of divalent cobalt, nickel and copper. Part II. The characterisation of a mixed ligand nickel(II) species and its thermal decomposition products. The crystal structure of (pyridine-2,6-dicarboxylato)(N,N,N′,N′-tetramethyl-1,2-diaminoethane)nickel(II) dihydrate

The magnetic and spectral properties of the complex Ni(pydca)(tmen)·2H 2O (1) and those of the thermally-derived species Ni(pydca)(tmen)·H 2O (2) and Ni(pydca)(tmen) (3) have been studied (pydca = pyridine-2,6-dicarboxylate, tmen = N,N,N,′,N′-tetramethyl-1,2-diaminoethane). Conflicting features in the electronic spectra prevented unambiguous stereo-chemical assignments. The presence of split ν 8(COO) and ν as(COO) infrared absorption bands in the regions 1350–1400 cm −1 and 1610–1680 cm −1 respectively suggested dissimilar co-ordination of the carboxylate groups. The structure of (1) has been determined by the heavy-atom technique and refined by least-squares. Crystals are triclinic, space group P 1 , with a = 10.806(5), b = 8.626(4), c = 9.825(5) Å, α = 114.32(2), β = 91.52(2), γ = 96.67(2)°, d obs = 1.50 (by flotation), d calc = 1.51 g cm −3 and Z = 2. With N obs = 2218, the final R factor was 0.047. Complex (1) is properly formulated as [Ni(pydca)(tmen)(H 2O)]·H 2O with Ni in a distorted octahedral environment, being bonded to two O atoms and the N atom of pydca, the two N atoms of tmen and one water molecule. The NiN(amine) distances differ significantly but structural parameters for the two carboxylate groups agree within experimental error. The anomalous spectral splitting appears to be common to analogous species containing fully-substituted diamines. Distorted octahedral and distorted square pyramidal symmetries are assigned to (2) and (3) respectively.

ChemInform Abstract: MIXED LIGAND NICKEL(II) COMPLEXES CONTAINING TETRATHIOMOLYBDATO AND TETRATHIOARSENATO GROUPS AND DIAMINES

Chemischer InformationsdienstVolume 8, Issue 47 Organoelement Compounds ChemInform Abstract: MIXED LIGAND NICKEL(II) COMPLEXES CONTAINING TETRATHIOMOLYBDATO AND TETRATHIOARSENATO GROUPS AND DIAMINES I. GERGEN, I. GERGENSearch for more papers by this authorR. MICU-SEMENIUC, R. MICU-SEMENIUCSearch for more papers by this authorI. HAIDUC, I. HAIDUCSearch for more papers by this author I. GERGEN, I. GERGENSearch for more papers by this authorR. MICU-SEMENIUC, R. MICU-SEMENIUCSearch for more papers by this authorI. HAIDUC, I. HAIDUCSearch for more papers by this author First published: November 22, 1977 https://doi.org/10.1002/chin.197747327Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume8, Issue47November 22, 1977 RelatedInformation

The electronic and vibrational spectra of t r a n s-[NiCl4(H2O)2]2− anions in crystalline Rb2NiCl4⋅2H2O and the effective symmetry of mixed-ligand nickel(II) complexes

Raman, far infrared, and electronic absorption spectra have been recorded for the [NiCl4(H2O)2]2− anion in dirubidium tetrachlorodiaquonickelate(II), Rb2NiCl4⋅2H2O. The vibrational spectra are analyzed in terms of an effective anion symmetry sufficiently low to remove all eigenstate degeneracies, while the d-electron ligand-field band shapes do not reflect the low crystallographic site symmetry of the Ni2+ ion. The effect of low symmetry and magnetic ordering on the polarized intensities of some zero-phonon electronic fine-structure lines is discussed, and the energy separations between these zero-phonon origins and vibronic side bands are correlated with the observed anion normal modes of vibration.

An Equilibrium Study of the Formation of Mixed-Ligand Nickel(II)-Aminopolycarboxylate Complexes

Abstract The equilibria for the formation of 1 : 1 : 1 ratio mixed-ligand complexes of nickel (II)–NTA, HIDA, and –emylenediamine-N,N′-diacetate (EDDA) complexes with the glycinate (Gly), glutamate (Glut), and aspartate (Asp) anions were studied by determining the effects of the Gly, Glut, and Asp anions on the rates of the substitution reactions of nickel(II)–NTA, –HIDA, and –EDDA complexes with EDTA-OH or DTPA.