Review Article

Theoretical Studies of Substitutionally Doped Single-Walled Nanotubes

Table 8

Free energies and rates of the Diels-Alder reaction of maleic anhydride and cyclopentadiene as catalyzed by alkyl- and arylplatinum complexes [45].

Catalyst Δ G e x o a Δ G b e x o Δ G e x o c Δ G d e x o ΔΔG‡e 𝑘 e n d o / 𝑘 f e x o 𝑘 c a t / 𝑘 g u n c a t

None27.28−3.8326.67−3.030.602.781.00

P t M e 3 + 15.85−8.0614.41−9.541.4411.431.27 × 103

P t P h 3 + 17.43−8.1916.82−8.480.612.791.58 × 103

Pt-doped phenaline17.69−8.1516.67−7.701.025.601.47 × 103

Pt-doped sumanene16.76−8.5716.19−8.400.572.633.01 × 103

Pt-doped corannulene16.03−13.2615.30−13.280.733.438.22 × 106

Pt-doped C24 PPP isomer23.54−4.0422.68−3.450.864.261.42

Pt-doped C24 HPP isomer23.49−4.4722.49−4.171.005.442.99

(5,0) Pt-doped SWCNT30.232.4730.11−3.470.121.230.55

aFree energy (in kcal/mol) required to reach transition state leading to exo-product at 298 K.
bFree energy (in kcal/mol) change to exo-product in at 298 K.
cFree energy (in kcal/mol) required to reach transition state leading to endo-product at 298 K.
dFree energy (in kcal/mol) change to endo-product at 298 K.
eDifference in free energy (in kcal/mol) changes required to reach transition states leading to endo- and exo-products at 298 K.
fRelative rate leading to endo-product versus exo-product.
gRelative rate of catalyzed Diels-Alder reaction versus uncatalyzed Diels-Alder reaction.