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.
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.
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.