14076-99-4Relevant articles and documents
The effect of pressure on the Raman spectra of solids. VII. The internal Raman bands in solid and coordinated pyridine
Heyns, A.M.,Venter, M.W.
, p. 7581 - 7591 (1990)
The pressure dependences of the internal Raman-active modes of solid pyridine and pyridine-d5 in both the crystalline and glassy modifications as well as of the complexes Zn(py)2Cl2, Ni(py)2Cl2, and Ni(py)4Cl2 are reported.When pyridine is frozen by the application of pressure, some ring modes as well as those involving the hydrogen atoms reflect this transformation.Upon the coordination of pyridine to metal ions, the ring vibrations show appreciable blue shifts.The pressure dependences of ν1, the C-C stretching mode, and ν12, the in-plane ring bending mode of the pyridine rings, are discussed in detail.The unusually high d5-h5 isotopic ratio of ν12 and its contrasting pressure dependences in the liquid and condensed phases of pyridine-d5 are explained.The association of pyridine molecules in the condensed phase does not occur through hydrogen bonds and the C-H stretching modes, in particular, show that repulsive intermolecular forces become very significant at higher pressures.The ratio of the intensities Ιν12/Ιν1 varies linearly with the strength of the M-N bonds in a series of pyridine complexes and a correlation also exists between Ιν12/Ιν1 and δν12/δp.The vibrations ν1 and ν2 are coupled through Fermi resonance in pyridine and its complexes and the pressure dependence of the Fermi resonance constant W is calculated for Zn(py)2Cl2.The C-H stretching modes reflect the presence of more than one distinct pyridine group in the lattice and are of much lower intensity than in complexes where only one distinct pyridine group is found.
Air-stable nickel precatalysts for fast and quantitative cross-coupling of aryl sulfamates with aryl neopentylglycolboronates at room temperature
Jezorek, Ryan L.,Zhang, Na,Leowanawat, Pawaret,Bunner, Matthew H.,Gutsche, Nicholas,Pesti, Aleksander K. R.,Olsen, James T.,Percec, Virgil
supporting information, p. 6326 - 6329 (2015/02/19)
A library containing 10 air-stable NiIIX(Aryl)(PCy3)2 complexes as precatalysts (X = Cl, Br, OTs, OMs, aryl = 1-naphthyl, 2-naphthyl; X = Cl, 1-acenaphthenyl, 1-(2-methoxynaphthyl), 9-phenanthrenyl, 9-anthracyl) was synthesized and demonstrated to quantitatively cross-couple 2-methoxyphenyl dimethylsulfamate with methyl 4-(5,5-dimethyl-1,3,2-dioxaborinane-2-yl)benzoate at 23 °C in dry THF in the presence of K3PO4(H2O)3.2 in less than 60 min. Lower or higher amounts of H2O in K3PO4 and as received THF mediate the same transformation in a maximum three times longer reaction time.
Hydromagnesation of Isoprene by Isopropylmagnesium Chloride in the Presence of Nickel(II) Compounds
Viktorov, N. B.,Zubritskii, L. M.
, p. 267 - 270 (2007/10/03)
The reaction of isoprene with alkylmagnesium halides in the presence of nickel complexes with phosphine oxides and nitrobgen-containing ligands gives dimeric hydromagnesation products along with monomeric magnesium-containing allyl-type products.
