Student no.: __56612785_____________
Name: __MAN Chun Long Constantin__
CHEM3053 Homework 1 (submit to CANVAS electronically on or before Feb 29, 11:59 PM)
Report the energies in Hartrees (five decimal places), bond distances (three decimal places), bond angles
(one decimal place) and the energies in kJ/mol (one decimal place).
1. Complete the following table by performing geometrical optimizations and vibrational frequency
calculations for two isomers of C3H6: propene and cyclopropane. Run the calculations at the HF/631(d)
level using the Gaussian-16 and Gaussview programs.
Propene
Cyclopropane
Draw the
optimized
structure, write
the C-C
and C-H bond
lengths in
the figure
C-C bond lengths: 1.50261
C=C bond lengths: 1.31842
C-H bond lengths: 1.08695
C-C-H angle: 115.9
C-C-C angle: 125.2
C-C bond lengths: 1.50110
C-H bond lengths: 1.10413
H-C-H angle: 114.0
C-C-C angle: 60.0
D3h
Point group
C2v
-117.071471
-117.058865
0.085455
0.087266
+33.044
0
Eele + Enuc
of the
optimized
structure
(in Hartree)
ZPVE
of the
optimized
structure
(in Hartree)
Relative
stability
(in kJ/mol)
2. Use the “scan” function in Gaussian 16, explore the potential energy surface for the dihedral angle (ClCC-F) change from 0o to 180o in 1-chloro-2-fluoroethane (CH2F-CH2Cl) at the HF/6-31G(d) level, capture
and paste the “Scan of Total Energy” from Gaussview below.
Locate all the minimum structures, complete the table below. Report energies in Hartree (five decimal
places) and in kJ/mol (one decimal place).
minimum structure 1
minimum structure 2
Draw the Newman
projection of the structure
Point group
Eele + Enuc
of the optimized structure
(in Hartree)
C1
C2
-636.96424
-636.97667
0.06457
0.06465
ZPVE
of the optimized structure
(in Hartree)
0
Relative stability
(in kJ/mol)
32.635
(a) On the potential energy surface, identify the highest energy point and draw the Newman projection
of the structure below. Explain the reason why this structure has the highest energy.
3. Carry out G3 calculations to predict the Hf298 for CH4/CH4+, CH3/CH3+, D0(CH3 H), IE(CH3) and
IE(CH4). Complete the following tables with your results. Report energies in Hartree (five decimal
places), in kJ/mol (one decimal place) and in eV (one decimal place).
Species
Point
group
EG30
HG3298
(Hartree)
CH3
C3v
CH4
(Hartree)
G3 Hf298
(kJ/mol)
Exp’t Hf298
(kJ/mol)
-39.79329
-39. 78905
142.7
146.5
Td
-40.44763
-40.45381
-75.4
-74.61
CH3+
C3v
-39.43057
-39.42677
1093.9
1095.5
CH4+
Td
-39.99239
-39.98856
1146.1
1143.8
H
---
-0.50100
-0.44864
---
217.998
C
---
-37.77902
-37.792528
---
716.883
Energetic properties
G3 Prediction
EG30
Experimental data (eV)
IE(CH4)
12.7
12.618
0.004
IE(CH3)
9.9
9.8380
0.0004
D0(H3C H)
4.4
4.485
0.001