111-78-4Relevant articles and documents
CATALYTIC REACTIONS INVOLVING BUTADIENE. III. OLIGOMERIZATION WITH CATIONIC BIS(TRIPHENYLPHOSPHINE)(η3-ALLYL) COMPLEXES
Grenouillet, P.,Neibecker, D.,Tkatchenko, I.
, p. 213 - 222 (1983)
The bis(triphenylphosphine)(η3-crotyl)nickel cation is a catalyst precursor for the oligomerisation of butadiene to cyclic or linear dimers.Polymers and oligomers are also produced in variable amounts.The product distributions depend strongly on the type of solvent used and on the nature of co-catalysts.In the aprotic polar solvent DMF, the starting complex undergoes disproportionation, leading finally to a zerovalent nickel-phosphine catalyst.In protic solvents (alcohols) a cationic hydridonickel-phosphine catalyst is produced, but addition of sodium methoxide induces the formation of the zerovalent nickel-phospnine, therefore accounting for the changes in product selectivities.
Tada et al.
, p. 2871 (1969)
Bosmajian et al.
, (1964)
Corey,Wat
, p. 2757 (1967)
Day et al.
, p. 8289,8291 (1976)
Chapman et al.
, p. 2660,2663 (1964)
Martin,Eisenmann
, p. 661 (1975)
16-Electron Nickel(0)-Olefin Complexes in Low-Temperature C(sp2)-C(sp3) Kumada Cross-Couplings
Lutz, Sigrid,Nattmann, Lukas,N?thling, Nils,Cornella, Josep
supporting information, p. 2220 - 2230 (2021/05/07)
Investigations into the mechanism of the low-temperature C(sp2)-C(sp3) Kumada cross-coupling catalyzed by highly reduced nickel-olefin-lithium complexes revealed that 16-electron tris(olefin)nickel(0) complexes are competent catalysts for this transformation. A survey of various nickel(0)-olefin complexes identified Ni(nor)3as an active catalyst, with performance comparable to that of the previously described Ni-olefin-lithium precatalyst. We demonstrate that Ni(nor)3, however, is unable to undergo oxidative addition to the corresponding C(sp2)-Br bond at low temperatures (a nickel(0)-alkylmagnesium complex. We demonstrate that this unique heterobimetallic complex is now primed for reactivity, thus cleaving the C(sp2)-Br bond and ultimately delivering the C(sp2)-C(sp3) bond in high yields.
Platinum ω-Alkenyl Compounds as Chemical Vapor Deposition Precursors: Synthesis and Characterization of Pt[CH2CMe2CH2CH═CH2]2and the Impact of Ligand Design on the Deposition Process
Liu, Sumeng,Zhang, Zhejun,Gray, Danielle,Zhu, Lingyang,Abelson, John R.,Girolami, Gregory S.
, p. 9316 - 9334 (2020/11/12)
We describe the synthesis and characterization of three platinum(II) ω-alkenyl complexes of stoichiometry Pt[CH2CMe2(CH2)xCH═CH2]2 where x is 0, 1, or 2, as well as some related platinum(II) compounds formed as byproducts during their synthesis. The ω-alkenyl ligands in all three complexes, cis-bis(η1,η2-2,2-dimethylbut-3-en-1-yl)platinum (2), cis-bis(η1,η2-2,2-dimethylpent-4-en-1-yl)platinum (3), and cis-bis(η1,η2-2,2-dimethylhex-5-en-1-yl)platinum (4), bind to Pt by means of a Pt-alkyl sigma bond at one end of the ligand chain and a Pt-olefin pi interaction at the other; the olefins reversibly decomplex from the Pt centers in solution. The good volatility of 3 (10 mTorr at 20 °C), its ability to be stored for long periods without decomposition, and its stability toward air and moisture make it an attractive platinum chemical vapor deposition (CVD) precursor. CVD of thin films from 3 shows no nucleation delay on several different substrates (SiO2/Si, Al2O3, and VN) and gives films that are unusually smooth. At 330 °C in the absence of a reactive gas, the precursor deposits platinum containing 50% carbon, but in the presence of a remote oxygen plasma, the amount of carbon is reduced to below the Rutherford backscattering spectroscopy (RBS) detection limit without affecting the film smoothness. Under hot wall CVD conditions at 250 °C in the absence of a co-reactant, 72% of the carbon atoms in 3 are released as hydrogenated products (largely 4,4-dimethylpentenes), 22% are released as dehydrogenated products (all of which are the result of skeletal rearrangements), and 6% remain in the film. Some conclusions about the CVD mechanism are drawn from this product distribution.
