14949-69-0Relevant articles and documents
Dimerization of ethylene catalyzed by β-diketonate complexes of cobalt and nickel
Pillai,Tembe,Ravindranathan
, p. 171 - 183 (1990)
The M(acac)n-Rx Al2Cl6-x (M = Co, n = 2 or 3; Ni, n = 2; R = Et, i-Bu) system, both in the presence and absence of additives, is used for the dimerization of ethylene to a mixture of olefins consisting predominantly of 2-butenes. With the Co(acac)3-Al(i-Bu)3 system, a maximum conversion of 76% with selectivity to 2-butenes of 98 is achieved at 25°C and 8 kg cm-2 ethylene pressure. Selectivity to 2-butenes is higher with the Co(III) complex compared to Co(II) in combination with trialkylaluminum. However, the three-component Co(acac)2-Et2AlCl-PR3 system is superior to Co(acac)3-Et2AlCl-PR3 for the dimerization of ethylene to 2-butenes. The effects of ethylene pressure and reaction temperature on the activity and selectivity to 2-butenes are also investigated.
Mechanically activated solid-phase synthesis of nickel(II) β-diketonates
Petrova,Dudin,Makhaev,Zaitseva
, p. 587 - 592 (2008/10/09)
Mechanochemical solid-phase reactions between nickel chloride and sodium β-diketonates are studied. Nickel β-diketonates are isolated by vacuum sublimation from mechanically activated mixtures. The conversion of the starting compounds into nickel β-diketonates is 65-80%. The reaction course, product yield, and some properties of the activated mixtures are studied as functions of the mechanical treatment conditions and the nature of the reactants.
Dimerization of ethylene catalyzed by β-diketonate complexes of cobalt and nickel
Pillai, Muthukumaru S.,Tembe, G. L.,Ravindranathan, M.
, p. 171 - 184 (2008/10/08)
The M(acac)n-Rx Al2Cl6-x (M = Co, n = 2 or 3; Ni, n = 2; R = Et, i-Bu) system, both in the presence and absence of additives, is used for the dimerization of ethylene to a mixture of olefins consisting predominantly of 2-butenes. With the Co(acac)3-Al(i-Bu)3 system, a maximum conversion of 76% with selectivity to 2-butenes of 98 is achieved at 25°C and 8 kg cm-2 ethylene pressure. Selectivity to 2-butenes is higher with the Co(III) complex compared to Co(II) in combination with trialkylaluminum. However, the three-component Co(acac)2-Et2AlCl-PR3 system is superior to Co(acac)3-Et2AlCl-PR3 for the dimerization of ethylene to 2-butenes. The effects of ethylene pressure and reaction temperature on the activity and selectivity to 2-butenes are also investigated.
Bis(nitroxyl) adducts of cobalt and nickel hexafluoroacetylacetonates. Preparation, structures, and magnetic properties of M(F6acac)2(proxyl)2 (M = Co2+, Ni2+)
Porter, Leigh C.,Dickman, Michael H.,Doedens, Robert J.
, p. 1548 - 1552 (2008/10/08)
Bisadducts of the cyclic nitroxyl radical 2,2,5,5-tetramethylpyrrolidinyl-1-oxy (proxyl) with nickel(II) and cobalt(II) hexafluoroacetylacetonates have been prepared and characterized by crystal structure analyses and magnetic susceptibility studies. The adducts are isostructural, each having a centrosymmetric molecular structure and a slightly distorted octahedral configuration about the metal ion. The O-bound nitroxyls adopt a trans configuration. Magnetic susceptibility data (6-300 K) indicate that antiferromagnetic coupling of ligand and metal free spins yields an S = 1/2 ground state for M = Co2+ and an S = 0 ground state for M = Ni2+. At higher temperatures, there is some population of excited states with greater spin multiplicities. Possible orbital interactions that could account for the magnetic behavior are discussed. Crystal data for Co(F6acac)2(proxyl)2: monoclinic, space group P21/c, Z = 2, a = 10.339 (4) ?, b = 14.533 (4) ?, c = 11.973 (4) ?, β = 111.09 (2)°. Least-squares refinement based upon 1615 data with Fo2 > 3σ(Fo2) and 2θ ≤ 50° converged to R = 0.056. Crystal data for Ni(F6acac)2(proxyl)2: monoclinic, space group P21/c, Z = 2, a = 10.243 (5) ?, b = 14.564 (5) ?, c = 11.902 (5) ?. Least-squares refinement based upon 1609 nonzero data with 2θ ≤ 45° converged to R = 0.052.
Structure and magnetic properties of chains of diamonds of four spins formed by metal(II) hexafluoroacetylacetonates (metal = cobalt, nickel) and the nitronyl nitroxide radical 4,4,5,5-tetramethyl-2-ethyl-4,5-dihydro-1H-imidazolyl-1-oxyl 3-oxide
Caneschi,Gatteschi,Laugier,Rey,Sessoli
, p. 1553 - 1557 (2008/10/08)
Metal hexafluoroacetylacetonates, M(hfac)2 (M = Co, Ni), react with the nitronyl nitroxide radical 4,4,5,5-tetramethyl-2-ethyl-4,5-dihydro-1H-imidazolyl-1-oxyl 3-oxide, NITEt, yielding adducts of formula [M(hfac)2NITEt]2. The X-ray crystal structure of the cobalt derivative has shown that the compound crystallizes in the monoclinic system, space group P1, with a = 10.996 (3) ?, b = 11.479 (4) ?, c = 13.311 ?, α = 60.97 (2)°, β = 65.28 (2)°, γ = 81.67 (2)°, and Z = 1. The structure consists of dinuclear [Co(hfac)2NITEt]2 centrosymmetric units, with the nitronyl nitroxide radical bridging two different metal ions through one of its oxygen atoms. Weak interactions between different [M(hfac)2NITEt]2 groups cause the magnetic properties to be those of chains rather than of discrete clusters. The intermolecular coupling constant of [Ni(hfac)2NITEt]2 has been calculated from the low-temperature magnetic data as J′ = 2 cm-1 by applying the equation for S = 1 chains, while the intramolecular coupling constant has been estimated to be 300 cm-1 from the high-temperature data.
