Rep:Mod:tyy15 TStable

Exercise 1

reaction scheme

Figure 1: Reaction Scheme

MO

Figure 2: Molecular Orbital

Bond Lengths

Figure 3: Bond Length between Different Carbons

Table 1: Literature Values of C-C Bond Lengths And Van der Waals Radius of Carbon Atom

	Csp3-Csp3 (single bond)	Csp2=Csp2 (double bond)	Van der Waals Radius of C atom
Bond Length / Å	1.54	1.33	1.77

OR

Figure 3: Bond Length between Different Carbons

Table 1: Literature Values of C-C Bond Lengths And Van der Waals Radius of Carbon Atom Csp3-Csp3 (single bond) Csp2=Csp2 (double bond) Van der Waals Radius of C atom Bond Length / Å 1.54 1.33 1.77

IRC and Negative Frequency

Table 2: IRC and Negative Frequency at The Transition State

IRC	Negative Frequency at The Transition State

Exercise 2

Reaction Scheme

Figure 4:

MO

Figure 5:

Activation and Reaction Energy

Table 3: Energies of Reactants, Transition States and Products for Both Endo and Exo Pathways Pathway Energy / kJ mol-1 Reactants Transition States Products Activation Energy Reaction Energy Endo -1313781.87 -1313622.06 -1313849.28 159.81 -67.41 Exo -1313781.87 -1313614.23 -1313845.68 167.64 -63.81

Figure 6: Reaction Coordinate of Cyclohexadiene and 1,3-Dioxole

Steric Clash

Figure 7:

Exercise 3

Reaction Scheme

DA

Figure 8: Reaction Scheme

Internal DA

Figure 10: Reaction Scheme for Internal Diels-Alder Reaction

Activation and Reaction Energies

DA

Table 4: Energies of Reactants, Transition States and Products for Diels-Alder and Cheletropic Reactions Pathway Energy / kJ mol-1 Reactants Transition States Products Activation Energy Reaction Energy Endo Diels-Alder 158 238 57.0 79.8 -101 Exo Diels-Alder 158 242 56.3 83.8 -102 Cheletropic 158 260 0.00 102 -158

Figure 9: Reaction Coordinate

Internal DA

Table 5: Energies of Reactants, Transition States and Products for Internal Diels-Alder Reactions Pathway Energy / kJ mol-1 Reactants Transition States Products Activation Energy Reaction Energy Endo Diels-Alder 158 268 172 110 14.3 Exo Diels-Alder 158 276 177 118 18.8

Figure 11: Reaction Coordinate

IRC

DA + Cheletropic

Table 6: IRC Caluclations and Total Energy along IRC for Different Pathways

Pathway	IRC	Total Energy along IRC
Endo Diels-Alder
Exo Diels-Alder
Cheletropic

Internal DA

Table 7: IRC Caluclations and Total Energy along IRC for Internal Diels-Alder

Pathway	IRC	Total Energy along IRC
Endo Diels-Alder
Exo Diels-Alder

Electrocyclic

Figure 12:

Figure 13: HOMO of xylylene

Further Work / Investigation - Electrocyclic Reaction

Figure 14:Reaction Scheme for Electrocyclic Reaction

Figure 15:Reaction Rotation for Electrocyclic Reaction

Table 8: Energies of Reactants, Transition States and Products for Electrocyclic Reactions

Pathway	Energy / kJ mol-1
	Reactants	Transition States	Products	Activation Energy	Reaction Energy
Endo Diels-Alder	523.9	797.9	598.3	274.1	74.4

IRC Calculations can be found below in Table.9:

Table 9: IRC Calculations and Total Energy along IRC for Different Pathways

Pathway	IRC	Total Energy along IRC
Electrocyclic Reaction

Table 10: IRC Imaginary Frequency of Transition State Structure

Imaginary Frequency