林奕諄-第十二週作業

1.Find the transition state and calculate the barrier height for CH₃F + F⁻ → CH₃F + F⁻ with following model.

Model :
Gas/Microsolvation/Continuum Model ( PCM,sovlent=Water )

Method : MP2/aug-cc-pVDZ

(1)Gas

Figure 1 The transition state structure of gas model

IRC

Figure 2 The IRC calculation of the gas model

By performing IRC calculations, it ensures that the structure I have calculated represents the transition state between the two given structures.

**Table 1 Barrier height calculation of** **the** **gas model**
	reactant	transition state	product	barrier height(kcal/mol)	QCISD/MG3(kcal/mol)
energy ( hartree )	-239.10533	-239.08651	-239.10533	11.8	13.4[1]

[1]Zheng, J.; Zhao, Y.; Truhlar, D. G. J. Chem. Theory Comput. 2009, 5, 808-821.

(2)Microsolvation

600

Figure 3 The transition state structure of microsolvation model

water

Figure 4 The IRC calculation of the microsolvation model

Table 2 Barrier height calculation of the microsolvation model

reactant

transition state

product

barrier height(kcal/mol)

energy

( hartree )

-315.38149

-315.37293

-315.40571

20.6

(3)Continuum Model

Figure 5 The transition state structure of continuum model

Figure 6 The IRC calculation of the continuum model

Table 3 Barrier height calculation of the continuum model