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An experimental study of the thermal decomposition of a β‐hydroxy alkene, 3‐methyl‐3‐buten‐1‐ol, in m‐xylene solution, has been carried out at five different temperatures in the range of 513.15–563.15 K. The temperature dependence of the rate constants for the decomposition of this compound in the corresponding Arrhenius equation is given by ln k (s?1) = (25.65 ± 1.52) ? (17,944 ± 814) (kJ·mol?1)·T?1. A computational study has been carried out at the M05–2X/6–31+G(d,p) level of theory to calculate the rate constants and the activation parameters by the classical transition state theory. There is a good agreement between the experimental and calculated rate constants and activation Gibbs energies. The bonding characteristics of reactant, transition state, and products have been investigated by the natural bond orbital analysis, which provides the natural atomic charges and the Wiberg bond indices. Based on the results obtained, the mechanism proposed is a one‐step process proceeding through a six‐membered cyclic transition state, being a concerted and slightly asynchronous process. The results have been compared with those obtained previously by us (Struct Chem 2013, 24, 1811–1816) for the thermal decomposition of 3‐buten‐1‐ol, in m‐xylene solution. We can conclude that in the compound studied in this work, 3‐methyl‐3‐buten‐1‐ol, the effect of substitution at position 3 by a weakly activating CH3 group is the stabilization of the transition state formed in the reaction and therefore a small increase in the rate of thermal decomposition. 相似文献
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Abstract Due to the wide use of polymers in medicine, researchers are required to solve a very important problem–to understand the interaction between materials of nonphysiological origin and the surrounding biological liquids, and tissues, particularly blood. 相似文献
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The effects of Coulomb stretching of the deuteron internal wavefunction upon calculated tensor analysing powers, in the reaction 208Pb(, p) 209Pb, are studied quantitatively, and shown to be small but not negligible. 相似文献
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Navin A Anthony DW Aumann T Baumann T Bazin D Blumenfeld Y Brown BA Glasmacher T Hansen PG Ibbotson RW Lofy PA Maddalena V Miller K Nakamura T Pritychenko BV Sherrill BM Spears E Steiner M Tostevin JA Yurkon J Wagner A 《Physical review letters》2000,84(2):266-269
We derive the formalism to obtain spatial distributions of collisional correlation times for macroscopic particles undergoing granular flow from pulsed gradient spin echo nuclear magnetic resonance diffusion data. This is demonstrated with an example of axial motion in the shear flow regime of a 3D granular flow in a horizontal rotating cylinder at one rotation rate. 相似文献
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Gade A Bazin D Brown BA Campbell CM Church JA Dinca DC Enders J Glasmacher T Hansen PG Hu Z Kemper KW Mueller WF Olliver H Perry BC Riley LA Roeder BT Sherrill BM Terry JR Tostevin JA Yurkewicz KL 《Physical review letters》2004,93(4):042501
The 9Be(32Ar, 31Ar)X reaction, leading to the 5/2+ ground state of a nucleus at the proton drip line, has a cross section of 10.4(13) mb at a beam energy of 65.1 MeV/nucleon. This translates into a spectroscopic factor that is only 24(3)% of that predicted by the many-body shell-model theory. We introduce refinements to the eikonal reaction theory used to extract the spectroscopic factor to clarify that this very strong reduction represents an effect of nuclear structure. We suggest that it reflects correlation effects linked to the high neutron separation energy (22.0 MeV) for this state. 相似文献
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J. A. Tostevin 《The European physical journal. Special topics》2007,150(1):67-70
Final-state-exclusive two-nucleon removal reaction data
from fast fragmentation beams can provide a demanding test of the
microscopic two-nucleon transition densities calculated from
large-basis shell model wave functions. The sensitivity of measured
partial cross sections to pairing and other correlations is
discussed. It is also suggested that the widths of the momentum
distributions of these partial cross sections will exhibit a strong
dependence on the final-state of the residue and the projectile
structure. 相似文献
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