79361-90-3Relevant academic research and scientific papers
EPR study of (η5-cyclopentadienyl)nickel(I) complexes with P-and N-donor ligands and 1,5-cyclooctadiene
Saraev,Kraikivskii,Zelinskii,Vil'ms,Matveev,Yunda,Fedonina,Lammertsma
, p. 397 - 401 (2006)
Mononuclear (η5-cyclopentadienyl)nickel(I) complexes with triphenylphosphine, triethylphosphite, 2,2'-bipyridyl, and 1,5-cyclooctadiene formed in the course of reduction of nickelocene were studied by EPR method. Monocyclopentadienyl Ni(I) complexes of the composition CpNiL2 were shown to form during nickelocene reduction irrespective of the method applied (the use of organometallic compound, alkali metal, thermal conditions) in the presence of stabilizing ligands L (L = PPh3, P(OEt)3, Bipy/2, COD/2) and in the course of contradisproportionation reaction between nickelocene and the corresponding NiL4 complex. It was found that in the structure of these CpNiL2 complexes (L = PPh3, P(OEt)3, Bipy/2), the main molecular axis is perpendicular to the L-Ni-L plane and these complexes should be considered as derivatives of trigonal structures of D 3h symmetry distorted by Cp ligand. In CpNi(COD) complex, the main axis passes through the Cpring center and this complex should be treated as a derivative of pentagonal structure of C 5v symmetry distorted by COD ligand. Nonequivalence of 31P nuclei results from vibronic interaction effect in tricoordinate structures in pseudodegenerate electron state (Jahn-Teller effect). Pleiades publishing, Inc. 2006.
Synthesis and reactions of nickel and palladium carbon-bound enolate complexes
Burkhardt, Elizabeth R.,Bergman, Robert G.,Heathcock, Clayton H.
, p. 30 - 44 (2008/10/08)
Nickel and palladium carbon-bound enolates of the general formula η5-C5R5(Ph 3P)MCHR′COR″ (R = H, CH3; R′ = H, CH3; R″ = t-Bu, Ph, O-t-Bu) were prepared. Cp*(Ph3P)NiCH2CO2-t-Bu (1e) was characterized by X-ray diffraction. Compound 1e crystallizes in the monoclinic space group P21/n with unit-cell dimensions a = 13.6110 (20) A?, b = 12.7454 (13) A?, c = 17.8571 (23) A?, β = 105.544 (11)°, Z = 4, observed data 4091, R = 4.53%, and Rw = 4.19%. Reactions of these nickel and palladium enolates with aldehydes and other electrophilic reagents were examined. The nickel ketone enolates were shown to react with 2 equiv of benzaldehyde to deliver products resulting from a Tischtschenko-type oxidation/reduction process. Cp(Ph3P)NiCH2CO-t-Bu reacts with phosphines (L) to yield paramagnetic nickel(I) complexes of general formula Cp(L)2Ni.
