Table 6.

Enthalpies of activation for gas phase addition of thiolate anion to 2,4-dinitrophenyl halides, kcal/mol^{a, b} (MP2/6-31+G*//HF/6-31+G*).

Substrate	ΔH‡ (kcal/mol)	iν (cm−1)
ArF	−25.2	269
ArCl	−22.6	298
ArBr	−24.0	324

^aFrequencies and zero-point energies were calculated at the HF/6-31+G* level, the ZPVE values scaled by 0.9153 as recommended by Scott, A.P.; Radom, L. J. Phys. Chem. 1996, 100, 16502.¹⁸

^bTransition states calculated at the MP2 level did not hold the leaving group.

^cThe imaginary frequencies are associated with the reaction coordinate for addition of SH⁻ to carbon-1.