Vacuum pyrolysis of N,N-dimethyl bicyclo[3.2.0]hepta-3,6-dien-1-amine — He I ultraviolet photoelectron spectroscopic and computational studies

2004 ◽  
Vol 82 (2) ◽  
pp. 80-86 ◽  
Author(s):  
Tom Bajorek ◽  
Nick H Werstiuk
Keyword(s):  
Dft Calculations ◽  
Photoelectron Spectroscopy ◽  
Authentic Sample ◽  
Zero Point ◽  
Photoelectron Spectra ◽  
Computational Studies ◽  
Zero Point Energy ◽  
Point Energy ◽  
Vacuum Pyrolysis ◽  
Cis Isomer

The photoelectron spectra of N,N-dimethylbicyclo[3.2.0]hepta-3,6-dien-1-amine (1) and its pyrolysate were obtained using an unique ultraviolet (UV) photoelectron (PE) spectrometer interfaced with a CW CO2 laser. Pyrolysis of 1 in the source chamber of the PE spectrometer initially generates the transient N,N-dimethylcyclohepta-1E,3Z,5Z-trien-1-amine (2) — the computed barrier is 21.5 kcal mol–1 — that isomerizes to the all-cis isomer with a barrier of only 5.0 kcal mol–1. There is no evidence for the formation of N,N-dimethycyclohepta-1Z,3E,5Z-trien-1-amine (4), formation of which has an zero-point-energy corrected barrier of 28.4 kcal mol-1. A PE spectrum of an authentic sample of N,N-dimethylcyclohepta-1Z,3Z,5Z-trien-1-amine (3) correlated well with the pyrolysis spectrum. Molecular orbitals and their energies were obtained with Becke3LYP calculations.Key words: vacuum pyrolysis, N,N-dimethylbicyclo[3.2.0]hepta-3,6-dien-1-amine, photoelectron spectroscopy, DFT calculations.

Bicyclo[3.2.0]hepta-1,3,6-triene — UV photoelectron spectroscopic and computational studies

2005 ◽  
Vol 83 (9) ◽  
pp. 1352-1359 ◽  
Author(s):  
T Bajorek ◽  
N H Werstiuk
Keyword(s):  
Carbon Atom ◽  
Dft Calculations ◽  
Photoelectron Spectroscopy ◽  
Amine Oxide ◽  
Authentic Sample ◽  
Ionization Potentials ◽  
Spectral Subtraction ◽  
Computational Studies ◽  
Simulated Spectrum ◽  
Uv Photoelectron Spectroscopy

Pyrolysis of N,N-dimethylbicyclo[3.2.0]hepta-3,6-dien-1-amine oxide (5) at 120 °C in the source chamber of the UV photoelectron (PE) spectrometer yielded bicyclo[3.2.0]hepta-1,3,6-triene (6). The triene dimerizes to yield a mixture of two dimers in equal amounts. A PE spectrum of an authentic mixture of dimers was also recorded for the purpose of spectral subtraction. Pyrolysis of 5 also generates dimethylhydroxylamine (7), a spectrum of which was also recorded from an authentic sample. Spectral subtraction allowed the first two ionization potentials of triene 6 at 7.2 and 9.8 eV to be identified. The resultant PE spectrum was compared very favorably with a simulated spectrum obtained from DFT calculations. A QTAIM analysis and calculation of delocalization indexes showed that while homoconjugation between C4 and C6 is negligible there is a weak through-space interaction between the bridgehead carbon atom C1 and C6 of the four-membered ring.Key words: bicyclo[3.2.0]hepta-1,3,6-triene, UV photoelectron spectroscopy, DFT calculations, QTAIM, delocalization indexes.

scholarly journals An investigation into the existence of zero-point energy in the Rock-Salt Lattice by an X-Ray Diffraction Method

1928 ◽  
Vol 118 (779) ◽  
pp. 334-350 ◽  
Keyword(s):  
Rock Salt ◽  
Diffraction Method ◽  
Zero Point ◽  
Temperature Factor ◽  
X Rays ◽  
Zero Point Energy ◽  
Chlorine Atoms ◽  
Point Energy ◽  
X Ray ◽  
State Of Rest

In the present paper we shall attempt to collate the results of four separate lines of research which, taken together, appear to provide some interesting checks between theory and experiment. The investigations to be considered are (1) the discussion by Waller* and by Wentzel,† on the basis of the quantum (wave) mechanics, of the scattering of radiation by an atom ; (2) the calculation by Hartree of the Schrödinger distribution of charge in the atoms of chlorine and sodium ; (3) the measurements of James and Miss Firth‡ of the scattering power of the sodium and chlorine atoms in the rock-salt crystal for X-rays at a series of temperatures extending as low as the temperature of liquid air ; and (4) the theoretical discussion of the temperature factor of X-ray reflexion by Debye§ and by Waller.∥ Application of the laws of scattering to the distribution of charge calculated for the sodium and chlorine atoms, enables us to calculate the coherent atomic scattering for X-radiation, as a function of the angle of scattering and of the wave-length, for these atoms in a state of rest, assuming that the frequency of the X-radiation is higher than, and not too near the frequency of the K - absorption edge for the atom.¶ From the observed scattering power at the temperature of liquid air, and from the measured value of the temperature factor, we can, by applying the theory of the temperature effect, calculate the scattering power at the absolute zero, or rather for the atom reduced to a state of rest. The extrapolation to a state of rest will differ according to whether we assume the existence or absence of zero point energy in the crystal lattice. Hence we may hope, in the first place to test the agreement between the observed scattering power and that calculated from the atomic model, and in the second place to see whether the experimental results indicate the presence of zero-point energy or no.

scholarly journals Zero-Point Energy Leakage in Quantum Thermal Bath Molecular Dynamics Simulations

2016 ◽  
Vol 12 (12) ◽  
pp. 5688-5697 ◽  
Author(s):  
Fabien Brieuc ◽  
Yael Bronstein ◽  
Hichem Dammak ◽  
Philippe Depondt ◽  
Fabio Finocchi ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Zero Point ◽  
Thermal Bath ◽  
Zero Point Energy ◽  
Point Energy ◽  
Energy Leakage ◽  
Dynamics Simulations

Electric field induced phase transition in first order ferroelectrics with large zero point energy

2008 ◽  
Vol 387 (1) ◽  
pp. 115-122 ◽  
Author(s):  
C.L. Wang ◽  
J.C. Li ◽  
M.L. Zhao ◽  
J.L. Zhang ◽  
W.L. Zhong ◽  
...  
Keyword(s):  
Phase Transition ◽  
Electric Field ◽  
Zero Point ◽  
Zero Point Energy ◽  
Point Energy ◽  
First Order

The zero-point energy for rotation

1978 ◽  
Vol 285 (1) ◽  
pp. 93-99 ◽  
Author(s):  
P. -G. Reinhard
Keyword(s):  
Zero Point ◽  
Zero Point Energy ◽  
Point Energy
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