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• 109-66-0 pentane 

Relevant academic research and scientific papers

A study of alkyl radicals in the matrix of polycrystalline n-alkane γ-irradiated at 77 K 1. Effect of chain length on ESR spectra of γ-irradiated linear alkanes

The composition of alkyl radicals (AR) formed by γ-radiolysis (T= 77 K) of polycrystalline n-alkanes with different lengths of the carbon chain (C(5), C(7), C(10), C(11), and C(18)) and their polymeric analog (polyethylene) was estimated from the ESR spectra. The ESR spectra of the irradiated n-alkanes are superpositions of the signals from the H3CC?HCH2~ and -CH2C ? HCH2~ radicals, whose HFS constants with α and β protons as well as the equilibrium conformation are independent of the chain length of the n-alkane molecule. A dependence of the concentration of the radicals on the chain length of n-alkane was found. The absence of the ~CH2C ? H2 radicals that may arise upon H atom elimination from the Me fragments of the n-alkane molecules is most likely related to the transfer of excitation energy from the Me group to the neighboring methylene fragment and the transformation of the ~CH2C ? H2 radicals into H3CC ? HCH2~ radicals. With account for this, the concentrations of the AR formed were suggested to be proportional to the number of H atoms at the corresponding C atom.

The dynamics of hydrogen abstraction reactions: Crossed-beam reaction Cl+n-C5H12→C5H11+HCl

We present a crossed molecular beam study of the dynamics of the metathesis reaction Cl+n-C5H12→HCl+C5H11 at a collision energy of 16.8 kcal/mol. The experiments were conducted on the Chemical Dynamics Beamline at the Advanced Light Source, using tunable undulator radiation to effect soft ionization of the pentyl radical product. Laboratory angular distributions and time-of-flight spectra at many laboratory angles were used to obtain the center-of-mass translational energy and angular distributions. These distributions were found to be strongly coupled, with the forward scattered pentyl radical formed extremely cold, while the backscattered radicals were formed leaving nearly 15 kcal/mol in internal energy in the products. These results are contrasted with recent studies on the analogous reaction with propane, suggesting in this case direct involvement of the carbon skeleton in the collision process.

Rapid and selective spiro-cyclisations of O-centred radicals onto aromatic acceptors

Substituted benzyloxycarbonyloxyl radicals were generated by sensitised photolyses of benzyl oxime carbonates. EPR spectroscopy showed they ring closed exclusively by spiro-cyclisation onto the ipso-C-atoms of the aromatic rings. β-Scission of the alkoxycarbonyloxyls to CO2 and benzyloxyl radicals increasingly competed and became dominant above 270 K. The first rate parameters for spiro-cyclisations of O-centred radicals onto aromatics were obtained by the steady-state kinetic EPR method. Pentafluoro-substitution of the ring substantially reduced the spiro-cyclisation rate. Activation barriers of the spiro-cyclisations were computed by DFT to be about half those of the alternative ortho-cyclisations. Consideration of the TS structures suggested the preference for spiro- over ortho-cyclisation resulted from better overlap of the oxyl SOMO with the aromatic π-system during spiro closure.

Reactions of Atomic Oxygen (3P) with Selected Alkanes

Rate constants for the reactions of atomic oxygen (3P) with selected alkanes (C2-C6 straight chain alkanes, c-C6H12, neo-C5H12, and i-C4H10) have been determined directly by a laser photolysis-shock tube-atomic resonance absorption method at hi