Rep:Wilee5534.3

The Cope Rearrangement Tutorial

Optimisation of anti and gauche conformers

ANTI anti optimisation File Name anti1_5_hexadiene_optimisation File Type .chk Calculation Type FOPT Calculation Method RHF Basis Set 3-21G Charge 0 Spin Singlet Total Energy -231.69253528 a.u. RMS Gradient Norm 0.00001891 a.u. Imaginary Freq Dipole Moment 0.0000 Debye Point Group

Symmetrize? Point Group = C_i

Energy given in table -231.69254, in agreement with my energy Total Energy -231.69253528

GAUCHE

HF/3-21G

File Name gauche1_5hexadiene_optimisation File Type .chk Calculation Type FOPT Calculation Method RHF Basis Set 3-21G Charge 0 Spin Singlet Total Energy -231.69266118 a.u. RMS Gradient Norm 0.00001742 a.u. Imaginary Freq Dipole Moment 0.3404 Debye Point Group

Symmetrized.. Point Group = C1

gauche conformer optimised with low level basis set HF/3-21G.jpg

Run anti2 again with B3LYP/6-31G*

anti2 high level optimisation File Name anti1_5_hexadiene_optimisation_highlevel File Type .chk Calculation Type FOPT Calculation Method RB3LYP Basis Set 6-31G(D) Charge 0 Spin Singlet Total Energy -234.61171027 a.u. RMS Gradient Norm 0.00000985 a.u. Imaginary Freq Dipole Moment 0.0000 Debye Point Group

anti conformer optimised with low level basis set HF/3-21G.jpg

anti conformer optimised with high level basis set B3LYP/6-31G*.jpg

Torsion Angles (high level) C 1,2,3,4 118.54991 C 2,3,4,5 180.0 C 3,4,5,6 118.54991

Torsion Angles (low level) C 1,2,3,4 114.66878 C 2,3,4,5 180.0 C 3,4,5,6 114.66878

Vibrational analysis of anti2

B3LYP/6-31G*

Modes all positive and real

Sum of electronic and zero-point Energies= -234.469203 Sum of electronic and thermal Energies= -234.461856 Sum of electronic and thermal Enthalpies= -234.460912 Sum of electronic and thermal Free Energies= -234.500777

Freq analysis ran at lower basis set for activation energies [later].

Sum of electronic and zero-point Energies= -231.539539 Sum of electronic and thermal Energies= -231.532565 Sum of electronic and thermal Enthalpies= -231.531621 Sum of electronic and thermal Free Energies= -231.570916

Optimising the Chair and Boat Transistion Structures

Chair Optimised to a TS (Berny)

Chair optimised to TS (Berny)

C-C [terminal] = 2.02055

Imaginary vibration at 817.9cm^-1

imaginary freq 817.9cm^-1

Optimised using frozen method

imaginary freq 818cm^-1