- Crystal growth and properties of PbI2 doped with Fe and Ni
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A procedure is described for doping PbI2 single crystals with Fe and Ni during vapor-phase growth in a closed system in the presence of excess iodine. The rate of mass transport in the system and the doping level of the crystals are shown to be governed by the dopant content in the source material and the source temperature. The effect of Fe and Ni doping on the low-temperature (5 K) exciton photoluminescence spectrum of PbI2 is discussed.
- Rybak,Lun',Bordun,Omelyan
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- The metal carbonyls
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When the metal carbonyls were first discovered, their properties were startling because they seemed to violate nearly all the previously recognized generalizations of chemistry. Even to-day the existence of the carbonyls is not particularly emphasized in
- Blanchard, Arthur A.
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- Infrared spectra of the gaseous iodides from chromium, iron and nickel
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The infrared spectra of the vapours above chromium, iron and nickel diiodide have been studied by high-temperature infrared spectroscopy.The gaseous molecules CrI2, FeI2 and NiI2 were all identified and the interpretation of the spectra is in agreement with a linear structure.Additional strong absorption bands in the spectra of the vapour phase above liquid CrO2 and FeI2 were assigned to dimeric (MI2)2 molecules.Valence force constants and thermodynamic quantities have been calculated.
- Konings, R. J. M.,Booij, A. S.
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- ENCAPSULATION OF THE TRANSITION METALS CHROMIUM THROUGH COBALT IN ZIRCONIUM CLUSTER IODIDES.
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The zirconium iodide phases discussed all possess clusters with a formal electron count of 18 or more. We detail our efforts concerning the synthesis, structural characterization, magnetic properties, and electronic structure of zirconium iodide cluster compounds featuring the enclosure of the transition metals Cr, Mn, Fe, and Co. It is found that the iron-zirconium bonding in the cluster is notably greater than that in Zr//3Fe. The phase CsZr//6I//1//4Mn is properly diamagnetic, while the magnetic susceptibility data for the 19-electron Zr//6I//1//2Mn are well described by a high-temperature mu //e//f//f of 1. 84 mu //B and an intracluster spin-orbit coupling that partially quenches the moment at lower temperatures.
- Hughbanks,Rosenthal,Corbett
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- Thermal studies of N(1)-isopropyl-2-methyl-1,2-propanediamine complexes of nickel(II)X2 [X = I(1-), CF3CO2(1-), 0.5SO4(2-) and 0.5SeO4(2-)] in the solid state
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The complexes NiL2X2.nH2O (L = N(1)-isopropyl-2-methyl-1,2-propanediamine; X = 0.5SO4(2-) when n = 0; X = I(1-) when n = 2; X = CF3CO2(1-) when N = 0 or 2 and X = 0.5SeO4(2-) when n = 0 or 3) have been synthesized and their thermal behaviour has been studied. All the hydrated complexes are yellow in colour and on heating lose water of hydration accompanied by a yellow light blue thermochromic transition, except in the case of the iodide complex, which retains the original yellow colour on dehydration. However, NiL2I2 undergoes an irreversible exothermic phase transition (166-193°C; ΔH = -7.5 kJ mol**-1) with change in colour from yellow to reddish yellow. NiL2(CF3CO2)2 shows a reversible phase transition (heating cycle, 144-170°C; ΔH = 3.1 kJ mol**-1; cooling cycle, 158-135°C; ΔH = -3.1 kJ mol**-1) with no visual change in colour. All the yellow complexes posses square-planargeometry and the light blue complexes NiL2X2 (X = CF3CO2(1-), 0.5SO4(2- ) and 0.5SeO4(2-)) are expected to be pentaccordinated. The phase transition occuring in NiL2X2 (X = I(1-) and CF3CO2(1-)) is due to conformational changes of the diamine chelate rings.
- Pariya, Chandi,Ghosh, Ashutosh,Ray Chaudhuri, Nirmalendu
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- Asymmetric reduction and hydrogenation over heterogeneous catalysts prepared by reacting nickel-boride with norephedrine
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Nanoparticles of NiB2 were prepared by reducing nickel iodide with lithium borohydride in anhydrous oxygen-free THF. The hydroxy group and the amino-group of norephedrine reacted with boron atoms, evolving 1 mol of hydrogen for each mole of amino alcohol to afford a chiral oxazaborolidine anchored at the surface of the particles. The reduction of acetophenone utilizing borane-THF as reducing agent in the presence of 1 equivalent of NiB2 bound oxazaborolidine afforded 1-phenylethanol was excellent enantioselectivity (ee). The oxazaborolidine was strongly bound to the particles since the catalyst could be recycled at least two times with no performance loss. The catalyst hydrogenated 4-methylpentan-2-one, isophorone, and acetophenone, into 4-methyl-pentan-2-ol, dihydroisophorone, and 1-phenylethanol, respectively, in any case the S configuration predominated slightly. The ee was constant when the catalyst was reused. The catalytic hydrogenation over an oxazaborolidine boron bound to Ni particles was not useful in the enantioselective synthesis of alcohol.
- Court,Molvinger,Lopez
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- Polymer complexes. LIV. Structural and spectral studies of supramolecular coordination polymers built from Ni(II), Fe(II) and Pd(II) with sulphadrug
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Polymer complexes of p-acrylamidyl sulphaguanidine (HL) with Ni(II), Fe(II) and Pd(II) salts have been prepared. The structures of the polymer complexes were elucidated using elemental analysis, 1H NMR, UV-Vis, IR spectroscopies, magnetic moment, molar conductance and thermal analysis. The polymer complexes were isolated in 1:1 and 1:2 (M:L) ratios. The solid monocomplexes (1:1) (M:L) were isolated in the general formula [Fe(HL)O 2SO2(OH2)2]. The biscomplexes (1:2) (M:L) solid chelates found to have the general formula [Ni(HL)2X 2]n (X = Cl-, Br-, I-, NO3, NCS- ), [Fe(HL)(en)(OSO3)(OH 2)]n and [Ni(HL)2(Py)2] nX2, while {[Pd(L)X]2}n (1:1) (X = Cl- or Br-). In all the polymer complexes the ligand and anions were found to be coordinated to the Ni(II) and Fe(II) ions. The bidentate nature of the ligand is evident from IR spectra. The magnetic and spectroscopic data indicate a octahedral geometry for complexes. The thermal behaviour of these chelates shows that the hydrated complexes loss water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps.
- El-Sonbati,Belal,Diab,Mohamed
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- Second harmonic generation in boracites
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The M3B7O13X (M=Mg, Ni, Cd; X=Cl, Br, I) boracites were synthesized and characterized by x-ray diffraction and second harmonic generation. Their nonlinear optical susceptibility was estimated using the Phillips-Van Vechten
- Zagudailova,Plachinda,Berdonosov,Stefanovich,Dolgikh
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p. 393 - 396
(2008/10/09)
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- Chemical bond and hybridization in nickel compounds
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By means of ultraviolet reflectance and valence band photoemission one can get a scale of ionicity for nickel halides. The fraction of ionic character of the chemical bond, from 0.72 in NiI2 to 0.80 in NiCl2, evaluated with the Phillips theory has been related to the ground state d electron counts ?ndn? calculated from Ni2p core photoemission. While the chemical trends of cluster model parameters are in general well reproduced, a systematic discrepancy in band gap values (2-3 eV) has been found by comparing core-level results with optical and photoconductivity data.
- Pollini I.
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- Thermal studies of N-phenylethane-1,2-diamine complexes of nickel(II) in the solid state
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[NiL3]X2, (where L = N-phenylethane-1,2-diamine and X = I- and ClO4-), [NiL2X2] (X is Cl-, Br-, NCS-, 0.5SO42- or 0.5SeOsu
- Das,Chaudhuri
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p. 895 - 902
(2008/10/08)
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- Macrocyclic selenoether complexes of nickel(II). Synthesis and properties of [NiX2([16]aneSe4)] ([16]aneSe4 = 1,5,9,13-tetra-selenacyclohexadecane, X = Cl, Br or I) and [NiX2(MeSeCH2CH2-SeMe)2]
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Reaction of NiX2 (X = Cl, Br or I) with [16]aneSe4 (1,5,9,13-tetraselenacyclohexadecane) under anhydrous conditions in n-butanol yielded trans-[NiX2([16]aneSe4)]. Similar reactions using MeSeCH2CH2SeMe produced trans-[NiX2(MeSeCH2CH2SeMe)2]. The complexes have been characterised by IR and UV/VIS spectroscopy and magnetic measurements. The crystal structure of [NiCl2(MeSeCH2CH2SeMe)2] showed an octahedral nickel centre co-ordinated to trans chlorines [2.370(2)-2.376(2) A] with the diselenoethers present as chelating ligands in the DL conformation [2.522(1)-2.5623(8) A]. Structural data on the very poorly soluble [16]aneSe4 complexes were obtained via nickel K-edge EXAFS (extended X-ray absorption fine structure), and the results compared with related complexes. A ligand field analysis of the UV/VIS spectra of (NiX2([16]aneSe4)] and of the tetrathioether analogues [NiX2(116]aneS4)] ([16]aneS4 = 1,5,9,13-tetrathiacyclohexadecane) showed that the ligand fields produced by 16-membered ring macrocycles [Dq(xy)] lie in the order N4 > S4 > Se4, with MeSeCH2CH2SeMe affording a stronger field that [16]aneSe4 due to the smaller chelate ring size.
- Davies, Maxwell K.,Levason, William,Reid, Gillian
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p. 2185 - 2189
(2007/10/03)
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- Primary aliphatic amine complexes of transition-metal halides: III. Thermal and spectroscopic characterization of solid methylamine complexes of nickel(II) halides
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The hexakis(methylamine) complexes of nickel(II)-chloride, -bromide and -iodide have been prepared using-gas phase preparation procedure. The thermal decomposition starts with the release of four moles of the organic ligand. The bis(methylamine) intermediate decomposes in one step to the pure nickel(II) halide in the case of the chloride compound, however one and a half moles of methylamine containing intermediates were identified for the bromide and iodide analogues. The UV/VIS and the far IR spectra of the hexakis complexes show a typical octahedral environment around the central nickel(II) ion.
- Kenessey,Carson,Allan,Wadsten,Liptay
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p. 167 - 173
(2008/10/08)
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- Thermal studies of 2-aminoethanol complexes of nickel (II) in the solid state
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[NiL3]X2 (where L = 2-aminoethanol and X is Cl-, Br-, I-, NO3-, 0.5SO42- or 0.5SeO42-) and [NiL2X2] (X is Cl-, Br-, or SCN-) have been synthesised from solution and their thermal study has been carried out in the solid phase. [NiL3]I2 and [NiL3]SeO4 undergo reversible endothermic phase transitions upon heating (63-93°C and 94-113°C, respectively, for heating and 94-65°C and 110-190°C, respectively, for cooling), whereas [NiL3](NO3)2 exhibits two successive reversible endothermic phase transitions (10-38°C and 50-62°C for heating and 56-48°C and 19 - (-8)°C for cooling). On the other hand, [NiL3]SO4 undergoes irreversible endothermic phase transition (99-112°C) in the solid state. All these transformations are assumed to be associated with the conformational changes of 2-aminoethanol chelate rings. [NiL2(NCS)2] melts at ～ 168°C and remains supercooled for a few days at ambient temperature. The initial temperatures of decomposition (Ti) of these complexes have been compared with those of the corresponding ethane-1, 2-diamine complexes of nickel (II).
- Das, Debasis,Ghosh, Ashutosh,Koner, Subratanath,Ray Chaudhuri, Nirmalendu
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- Preparation, characterisation and thermal behaviour of N-(3-aminopropyl)-1,3-propanediamine complexes of nickel(II) in the solid state
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The complexes [Ni(dpt)2]X2.nH2O (where dpt is N-(3-aminopropyl)1,3-propanediamine; n = 0 when X is I, NCS or ClO4; n = 1 when X is Cl, Br or NO3; n = .mchgt. 1 when X is 0.5SO4 and 0.5SeO4), Ni(dpt)X2.nH2O (n = 0 when X is Cl or NO3; n = 1 when X is Br or
- Pariya, Chandi,Ghosh, Ashutosh,Chaudhuri, Nirmalendu Ray
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p. 199 - 210
(2008/10/09)
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- Standard enthalpies of formation of crystalline iron and nickel iodides
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The enthalpies of the reactions of Fe(c), Ni(c), Br2(1), FeI2(c), NiI2(c), KI(c), KBr(c), and I2(c) with a bromide-bromide solution have been measured in the dissolution calorimeter with isothermal jacket of the LKB-8700 apparatus.By combining the results with published data the enthalpies of formation of iron and nickel iodides have been determined by two methods: ΔfH0(FeI2, c, 298.15 K) = -118.10 +/- 0.30 kJ mol-1 and ΔfH0(NiI2, c, 298.15 K) = -96.40 +/- 0.40 kJ mol-1).
- Efimov, M. E.,Evdokimova, V. P.
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p. 127 - 129
(2007/10/02)
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- Synthesis and structural and theoretical characterization of a nickel(0) complex of tribenzocyclyne (TBC) and the preparation of a novel organometallic conductor
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Reaction of Ni(COD)2 with TBC in benzene affords a planar nickel(0) complex, Ni(TBC), with the nickel atom coordinated equally by all three alkynes of the TBC ligand. The reaction chemistry of moderately reversible. Ni(TBC) is reduced with lithium, sodium, and potassium in various solvents (THF and DME) in the presence of various chelating agents (TMEDA, 18-crown-6, and cryptand-(2.2.2)) to the monoanion and dianion. The material [K(C222)]2[Ni(TBC)] was combined with Ni(TBC) to yield a conducting material. The maximum conductivity (via two-probe power compaction) was observed to be 2 × 10-3 (Ω cm)-1 at 0.5 electron per Ni(TBC) unit. A parallel study on TBC showed a maximum conductivity of 8 (2) × 10-5 (Ω cm)-1 at 0.6 electron per TBC unit.
- Ferrara,Tanaka,Fierro,Tessier-Youngs,Youngs
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p. 2089 - 2098
(2008/10/08)
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- Rare-earth-metal iodide clusters centered by transition metals: Synthesis, structure, and bonding of R7I12M Compounds (R = Sc, Y, Pr, Gd; M = Mn, Fe, Co, Ni)
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The compounds R7I12M (M = Co, Ni for R = Sc; M = Fe, Co for R = Y; M = Mn, Fe, Co for R = Gd; M = Mn, Fe, Co, Ni for R = Pr) have been synthesized by reactions of RI3, MI2, and R metals at 750-950°C in sealed Nb or Ta containers. These compounds all adopt the Sc(Sc6Cl12B) structure (space group R3, Z = 3) with a transition metal at the cluster center (in place of boron). The seventh isolated R3+ ion can be substituted by Ca2+ in several of the Pr and Gd cases. The structural details of Sc7I12Co, Y7I12Fe, and (Ca0.65Pr0.35)(Pr6I12Co) were determined by single-crystal X-ray diffraction methods (a = 14.800, 15.351, 15.777 A?; c = 10.202, 10.661, 10.925 A?; R = 3.3, 3.8, 3.4%; Rw = 6.7, 3.3, 3.5%, respectively). The last of these presented twinning difficulties endemic to this structure type, but these were overcome satisfactorily by an approximate separation procedure. R-M distances in the clusters are short; Pr-Co = 2.770, Y-Fe = 2.621, and Sc-Co = 2.431 A?. While MO theory provides some useful guides to these compounds' stability, the true breadth of the chemistry possible remains to be explored.
- Hughbanks, Timothy,Corbett, John D.
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p. 2022 - 2026
(2008/10/08)
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- STUDIES ON TRANSITION-METAL PICOLINE COMPLEXES - I. PREPARATION AND THERMOANALYTICAL INVESTIGATIONS.
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A large number of transition-metal picoline halides were prepared, and their thermal decompositions were investigated by TG, DTG, DTA and thermomicroscopy. The compounds were classified on the basis of their thermal properties and two possible mechanisms of thermal decomposition were established.
- Liptay,Borbely-Kuszmann,Nagy
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- Macrocyclic Complexes: Part XI - Macrocyclic Complexes of Cobalt(II) and Nickel(II) with 1,4,5,7,8,11,12,14-Octaazacyclotetradeca-1,3,8,10-tetraene
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A series of macrocyclic complexes of cobalt(II) and nickel(II) with the ligand tetraeneN8 have been isolated by the action of formaldehyde on bis-glyoxal dihydrazone chelates of cobalt(II) and nickel(II).The reaction is proton catalysed and the coordination template effect governs the steric course of the reaction.The structures of the complexes have been elucidated on the basis of IR and electronic spectral data and magnetic properties.For each of the complexes, a well-defined reduction wave corresponding to the formation of species where the metal ion can be formally assigned an oxidation state +1 has been observed.The reduction for each macrocycle is more anodic, which is of the order 0.3 V, compared to that for its parent nonmacrocyclic complexes.
- Sahoo, Bhagirathi,Rout, A. K.,Sahoo, B.
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p. 609 - 614
(2007/10/02)
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- Hydrogenation process
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Process for the hydrogenation of functionally substituted acetylenic compounds employing catalyst comprising nickel boride on an inorganic oxide support is disclosed. Functionally-substituted acetylenic compounds are selectively reduced under mild reaction conditions to give functionally-substituted cis-olefinic compounds in high yield.
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- Coordination compounds of nickel(II) salts with substituted pyridines. Complexes of 2-, 3-, and 4-methylpyridine
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Complexes of 2-, 3-, and 4-methylpyridine (2-pic, 3-pic, and 4-pic) with a number of Ni(II) salts (chloride, bromide, iodide, nitrate, perchlorate, and tetrafluoroborate) were prepared and investigated. Three series of complexes were obtained, Ni(pic)X2 (pic = 2-pic, 3-pic; X = Cl, Br); Ni(pic)2X2 (pic = 2-pic, 3-pic, 4-pic; X = Cl, Br, I, NO3); Ni(pic)4X2 (pic = 3-pic, 4-pic; X = Cl, Br, I, NO3, ClO4, BF4). The complex Ni(3-pic)4X2 (X = ClO4, BF4) was obtained in two isomeric forms, identified as [Ni(3-pic)4X2] and [Ni(3-pic)4]X2, respectively. The complexes of 4-aminopyridine, Ni(4-NH2py)4X2 (X = Cl, Br, I, ClO4), were also prepared and investigated. The stoichiometry and stereochemistry of the complexes were correlated with the properties of the anion and ligand, in particular with the basicity and steric requirements of the latter.
- Vallarino,Hill,Quagliano
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p. 1598 - 1604
(2008/10/08)
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