Table 4. Gas phase barrier heights and reaction energies computed using B3LYP/6-311+G(2d,2p)// B3LYP/6-31G(d,p), PM6//B3LYP/6-31G(d,p), and PM6//PM6 (“PM6 opt”) using the largest and smallest structural models.

	AspDC	4-OT-1	4-OT-2	HKMT	HheC	MAD
Large structural models
Barrier heights
B3LYP	13.5	6.9	−1.6	18.9	18.2
PM6	11.9	1.4	−1.5	27.8	28.0	5.2
PM6 opt	15.8	7.3	17.3	27.5	26.4	7.7
Reaction energies
B3LYP	9.0	−5.7	−2.9	−9.2	5.5
PM6	2.0	−8.4	−1.7	−10.0	13.6	4.0
PM6 opt	3.5	5.6	−3.0	−12.7	14.2	5.8
Small structural models
Barrier heights
B3LYP	0.1	12.8	7.0	18.8	23.0
PM6	−1.5	5.4	0.9	29.2	37.4	8.0
PM6 opt	1.6	3.7	−1.1	32.6	28.8	7.6
Reaction energies
B3LYP	−9.5	9.8	−3.7	−2.9	17.5
PM6	−15.5	1.3	−3.6	−5.5	30.8	6.1
PM6 opt	−10.7	−4.6	−3.2	5.4	15.6	5.3