Thermodynamic Values of new Groups

The thermochemical properties of all groups are estimated the way described above and listed below in Table 4.7. Each groups is estimated from only one molecule system except for the calculation of O/CD/0, O/CT/0, CT/0 and 0/C/CT groups which are based on 2 to 5 molecules. The detailed calculations for these four groups are given in Table 4.6. All groups are derived from thermodynamic data determined by DFT calculations and isodesmic reactions. 

The group value of CT/0 (Table 4.6) is determined from ethynyl alcohols, ethynol (HC COH) and methyl ethynol (CHsC COH). Results for both species are discussed in Chapter 3. The enthalpy value for CT/0 is calculated to be 31.79 kcal mol based on HC COH and 30.39 kcal mof based on CHsCsCOH. The recommended value of CT/0 is taken as the average, 30.79 kcal mof and given in Table 4.7. 

The value of 0/C/CT group is derived from enthalpy values for HCsCOCHs and CHsC COCHs calculated in Chapter 3. 0/C/CT derived from HC COCHs and CHsC COCHs are -21.94 and -21.89 kcal mof respectively. Enthalpy, A// 298 °f the 0/C/CT group is the 

The O/CT/0 group value is derived from the enthalpy values of ethynyl hydroperoxides HC COOH and CHsC COOH. The value for O/CT/0 is -0.77 kcal moT This 

O/CD/0 entropy value of (CH3)2C=CHOOH which contains two methyl rotors on the non peroxide double-bond carbon has the lowest value, 5.26 cal mol K.  

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