A Configurational Contribution to the Heat Capacity of Gaseous(HDO)2

1991 ◽  
Vol 46 (1-2) ◽  
pp. 39-42
Author(s):  
Zdenek Slanina ◽  
Andrey G. Kalinichev

Abstract(HDO)2 can form two isomeric species, HOD.OHD and DOH.OHD. The species are studied in terms of the Bopp-Jancsö-Heinzinger potential. The deuterium-bonded structure is stabilized in zero-point vibrational energy by about 0.77 kJ mol-1 over the hydrogen-bonded one. In gas-phase the exactly equal stability of both structures would however be reached at a temperature of 638 K. The thermodynamic functions of HOD.OHD and DOH.OHD are different and, moreover, they essentially differ from the (overall) functions belonging to the equilibrium mixture of both structures (which is understood as one pseudospecies). For the heat capacity at constant pressure it is shown that a maximum of the difference between the pseudospecies' overall value and the HOD.OHD value appears at a temperature of about 39 K, amounting to some 4.6 J K-1mol-1

1990 ◽  
Vol 05 (20) ◽  
pp. 3901-3928 ◽  
Author(s):  
K. DEPTA ◽  
J. A. MARUHN ◽  
HOU-JI WANG ◽  
A. SĂNDULESCU ◽  
W. GREINER ◽  
...  

Two new macroscopic models (liquid drop and Yukawa-plus-exponential) describing the decays with emission of large fragments including alpha decay are developed. The proposed shape parametrization consists of two intersecting spheres smoothly joined by a third "rolling sphere". The first two spheres describe asymptotically the charge and mass asymmetries and the third one the necking-in process. It is shown that the potential energy surfaces in the neck and the relative distance between the centers of the spheres (for a given mass and charge fragmentation) lead to different dynamical paths depending on the mass and charge of the emitted fragment. Along the path a phenomenological shell correction term and a zero point vibrational energy are introduced. It is shown that this model gives an excellent description of the present experimental data.


1991 ◽  
Vol 84 (1-2) ◽  
pp. 1-17 ◽  
Author(s):  
James F. Annett ◽  
Milton W. Cole ◽  
Peter B. Shaw ◽  
Richard M. Stratt

2004 ◽  
Vol 108 (23) ◽  
pp. 4995-4997 ◽  
Author(s):  
Alexey L. Kaledin ◽  
Sharif D. Kunikeev ◽  
Howard S. Taylor

1998 ◽  
Vol 53 (10-11) ◽  
pp. 896-902 ◽  
Author(s):  
Jörg Fleischhauer ◽  
Gerhard Raabe ◽  
A. G. Santos ◽  
Jan Schiffer ◽  
Axel Wollmer

Abstract The absolute configurations of both 1,5-diaza-c/s-decalin enantiomers were determined by com-parison of measured and calculated CD spectra.CD spectra for both enantiomers were recorded. Theoretical CD spectra for one of the isomers were calculated by means of the semiempirical CNDO/2S method. Eight local minima on the energy hypersurface of the title compound were used to describe the conformer equilibrium mixture. The geometries of these conformers were calculated employing one-determinant ab initio calculations using the split valence 6-31G* basis set. Boltzmann factors were then obtained using relative energies calculated with three different basis sets and including correlation(MP2)-and zero point vibrational energy.Comparing the sign of the observed and calculated longest wavelength Cotton effect, we assign an absolute configuration to the compound. This assignment was verified by means of X-ray structure determination of one of the enantiomers’ α-methoxy-α-trifluoromethylphenyl aceticacid (MTPA, Mosher’s reagent) derivative.


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