Difference between revisions of "Hayalex1"
| Line 503: | Line 503: | ||
Low frequencies --- 0 0 0 | Low frequencies --- 0 0 0 | ||
</pre> | </pre> | ||
| + | ===H-Cl bond distances=== | ||
| + | {| class="wikitable" | ||
| + | |<b>Molecule/ion</b>|| HMim-Cl (a) || HMim-Cl (b) || HMim-Cl (c) | ||
| + | |- | ||
| + | |<b>r(H-Cl) (Â)</b>|| 1.720 || 2.277 (Me-H-Cl)<br>2.134 (C-H-Cl) || 2.417 (Me-H-Cl)<br>2.030 (C-H-Cl) | ||
| + | |} | ||
| + | |||
| + | * The H-Cl bond of HMim-Cl (a) is a similar length to that of Me<sub>3</sub>NH-Cl (1.720Â vs 1.728Â respectively), while the H-Cl bonds in HMim-Cl (b), (c) are significantly longer than the Me<sub>3</sub>NH-Cl H-Cl bond (2.0-2.4$Acirc; vs 1.728$Acirc;). | ||
Revision as of 05:47, 27 May 2026
Contents
lab marking
You have a good working wiki. It would be good if you report values of wavenumber in your answers. Overall a very good attempt. If you have any specific questions, do email Prof. Hunt
NH3
Calculation Data
Optimisation of NH3 was performed using the following parameters:
| Log file | AH_opf_pop.log |
| Molecule | NH3 |
| Method | RB3LYP |
| Basis set | 6-31G(d,p) |
| Final energy | -56.55777 au |
| RMS gradient | 0.000000 |
| Point group | C3V |
Log file
Convergence data
The following data was collected from the log file, confirming convergence.
Item table
Item Value Threshold Converged? Maximum Force 0.000000 0.000015 YES RMS Force 0.000000 0.000010 YES Maximum Displacement 0.000003 0.000060 YES RMS Displacement 0.000001 0.000040 YES
Low frequencies
Low frequencies --- -5.6864 -3.6131 -3.6124 0.0017 0.0048 0.0162 Low frequencies --- 1089.3674 1693.9284 1693.9284
Optimised molecule
Molecule parameters
- r(N-H): 1.02Â
- θ(H-N-H): 106°
Molecular structure
NH3 top-down view
NH₃ 3D view |
Vibrational analysis and IR spectrum
| Mode | 1 | 2 | 3 | 4 | 5 | 6 |
| Wavenumber (cm-1) | 1089 | 1694 | 1694 | 3461 | 3590 | 3590 |
| Symmetry | A1 | E | E | A1 | E | E |
| Intensity | 145 | 14 | 14 | 1 | 0 | 0 |
Charge distribution
| Atom | N | H |
| Charge (e) | -1.13 | +0.38 |
cis-N2F2 (Project molecule)
Calculation Data
Optimisation of N2F2 was performed using the following parameters:
| Log file | AH_N2F2_OPTF_POP.LOG |
| Molecule | N2F2 |
| Method | RB3LYP |
| Basis set | 6-31G(d,p) |
| Final energy | -309.01241 au |
| RMS gradient | 0.000000 |
| Point group | C2V |
Log file
Convergence data
The following data was collected from the log file, confirming convergence.
Item table
Item Value Threshold Converged? Maximum Force 0.000001 0.000015 YES RMS Force 0.000000 0.000010 YES Maximum Displacement 0.000001 0.000060 YES RMS Displacement 0.000001 0.000040 YES
Low frequencies
Low frequencies --- 0.0014 0.0022 0.0022 3.2225 4.3532 5.1001 Low frequencies --- 347.8772 561.2472 771.6105
Optimised molecule
Molecule parameters
- r(N-F): 1.39Â
- r(N=N): 1.22Â
- θ(F-N=N): 114°
- θ(F-N=N-F): 0°
Molecular structure
N2F2 2D view
N₂F₂ 3D view |
Vibrational analysis and IR spectrum
Data
| Mode | 1 | 2 | 3 | 4 | 5 | 6 |
| Wavenumber (cm-1) | 348 | 561 | 772 | 949 | 987 | 1637 |
| Symmetry | A1 | A2 | B2 | A1 | B2 | A1 |
| Intensity | 1 | 0 | 75 | 75 | 81 | 21 |
- The 3N-6 rule gives us an expected 6 vibrations (3 × 4 - 6 = 6).
- There are only 4 peaks on the IR spectrum because two of the vibrational modes have a negligible change in dipole moment, so they are not visible via IR spectroscopy.
- Vibrational mode 3 represents the asymmetric N-F stretching vibration.
- The highest energy mode is the N=N stretching vibration.
Charge distribution
cis-N2F2 has a charge separation driven by the high electronegativity of the fluorine atoms.
| Atom | N | F |
| Charge (e) | +0.22 | -0.22 |
Molecular orbital analysis
- MOs 1-4 correspond to the core orbitals of the atoms.
Molecular Orbital 9
The 9th molecular orbital of cis-N2F2 can be represented as the in-phase addition of the pz orbitals on the N and F atoms.
BH3
Calculation Data
Optimisation of BH3 was performed using the following parameters:
| Log file | AH_bh3_opt.log |
| Molecule | BH3 |
| Method | RB3LYP |
| Basis set | 6-31G(d,p) |
| Final energy | -26.61532 au |
| RMS gradient | 0.000002 |
| Point group | D3h |
Log File
Convergence data
The following data was collected from the log file, confirming convergence.
Item table
Item Value Threshold Converged? Maximum Force 0.000004 0.000015 YES RMS Force 0.000003 0.000010 YES Maximum Displacement 0.000017 0.000060 YES RMS Displacement 0.000011 0.000040 YES
Low frequencies
Low frequencies --- -11.6940 -11.6861 -6.5543 0.0007 0.0280 0.4289 Low frequencies --- 1162.9745 1213.1390 1213.1392
Rounded to accurate significant figures:
Low frequencies --- -12 -12 -7 0 0 0 Low frequencies --- 1163 1213 1213
Optimised molecule
Molecule parameters
- r(B-H): 1.192Â
- θ(H-B-H): 120.0°
Molecular structure
BH3 2D view
BH₃ 3D view |
NH3BH3
Calculation Data
Optimisation of NH3BH3 was performed using the following parameters:
| Log file | AH_bh3_opt.log |
| Molecule | BH3 |
| Method | RB3LYP |
| Basis set | 6-31G(d,p) |
| Final energy | -83.22469 au |
| RMS gradient | 0.000001 |
| Point group | C3v |
Log File
Convergence data
The following data was collected from the log file, confirming convergence.
Item table
Item Value Threshold Converged? Maximum Force 0.000002 0.000015 YES RMS Force 0.000001 0.000010 YES Maximum Displacement 0.000017 0.000060 YES RMS Displacement 0.000008 0.000040 YES
Low frequencies
Low frequencies --- -5.4185 -0.3223 -0.0476 -0.0003 1.1368 1.2200 Low frequencies --- 263.2927 632.9711 638.4651
Rounded to accurate significant figures:
Low frequencies --- -5 0 0 0 1 1 Low frequencies --- 263 633 638
Optimised molecule
Molecule parameters
- r(B-H): 1.210Â
- r(N-H): 1.018Â
- r(B-N): 1.668Â
- θ(H-B-H): 113.9°
- θ(H-N-H): 107.9°
- θ(N-B-H): 104.6°
- θ(B-N-H): 111.0°
- θ(H-B-N-H): 60.0°
Molecular structure
BH3 2D view
BH₃ 3D view |
NH3-BH3 association energy
The energies of NH3BH3 and its substituent fragments are as follows:
| Molecule | E (AU) |
| NH3 | -56.55777 |
| BH3 | -26.61532 |
| NH3BH3 | -83.22469 |
From this, we find the association energy: ΔE = E(NH3BH3) - E(NH3) - E(BH3) = -0.05160 AU = -135kJ/mol
Me3NHCl
Calculation Data
Optimisation of Me3NHCl was performed using the following parameters:
| Log file | AH_Me3NHCl_optf.log |
| Molecule | Me3NHCl |
| Method | RB3LYP |
| Basis set | 3-21G |
| Final energy | -632.16208 |
| RMS gradient | 0.000007 |
| Point group | C1 |
Log File
Convergence data
The following data was collected from the log file, confirming convergence.
Item table
Item Value Threshold Converged? Maximum Force 0.000020 0.000450 YES RMS Force 0.000004 0.000300 YES Maximum Displacement 0.001396 0.001800 YES RMS Displacement 0.000356 0.001200 YES
Low frequencies
Low frequencies --- -3.8137 -1.4370 -0.0040 -0.0040 -0.0031 6.6293 Low frequencies --- 55.9908 57.0177 190.1670
Rounded to accurate significant figures:
Low frequencies --- -4 -1 0 0 0 7 Low frequencies --- 56 57 190
Optimised molecule
Molecule parameters
- r(N-H): 1.164Â
- r(N-C): 1.504Â
- r(C-H): 1.091Â
- r(N-Cl): 2.902Â
- θ(H-N-C): 106.3°
- θ(N-C-H): 108.1°
- θ(H-C-H): 109.1°
Molecular structure
Me3NHCl view
Me₃NHCl 3D view |
Rigid scan
A rigid scan was performed, measuring the potential energy curve produced by increasing the N-H bond length from 0.8Â to 2.1Â in 0.1Â steps.
The following potential energy surface was generated:
Ionic liquids: HMim-Cl
Method data
| Molecule/ion | HMim-Cl (a) | HMim-Cl (b) | HMim-Cl (c) | HMim+ (a/b) | HMim+ (c) | Cl- |
| Log file | Log | Log | Log | Log | Log | Log |
| Method | RB3LYP | |||||
| Basis set | 3-21G | |||||
| Final energy (au) | -722.687898 | -722.666201 | -761.779525 | -264.455119 | -303.559223 | -458.057087 |
| RMS gradient | 0.000015 | 0.000012 | 0.000006 | 0.000011 | 0.000002 | 0.000000 |
| Point group | C1 | Oh | ||||
Convergence data
HMim-Cl (a)
Item Table
Item Value Threshold Converged? Maximum Force 0.000050 0.000450 YES RMS Force 0.000009 0.000300 YES Maximum Displacement 0.006960 0.001800 NO RMS Displacement 0.001143 0.001200 YES
Low frequencies
Low frequencies --- -5.1413 -2.9822 -0.0040 -0.0023 0.0006 2.8476 Low frequencies --- 36.2291 64.4325 80.8238
Rounded to accurate significant figures:
Low frequencies --- -5 -3 0 0 0 3 Low frequencies --- 36 64 81
HMim-Cl (b)
Item Table
Item Value Threshold Converged? Maximum Force 0.000030 0.000450 YES RMS Force 0.000008 0.000300 YES Maximum Displacement 0.001181 0.001800 YES RMS Displacement 0.000318 0.001200 YES
Low frequencies
Low frequencies --- -4.5351 -2.2938 -0.0010 0.0014 0.0015 1.1916 Low frequencies --- 45.5744 162.0373 198.8263
Rounded to accurate significant figures:
Low frequencies --- -5 -2 0 0 0 1 Low frequencies --- 46 162 199
HMim-Cl (c)
Item Table
Item Value Threshold Converged? Maximum Force 0.000013 0.000450 YES RMS Force 0.000004 0.000300 YES Maximum Displacement 0.000848 0.001800 YES RMS Displacement 0.000168 0.001200 YES
Low frequencies
Low frequencies --- -3.9219 -3.0567 -0.0023 0.0025 0.0030 2.3020 Low frequencies --- 52.1725 102.5709 107.1144
Rounded to accurate significant figures:
Low frequencies --- -4 -3 0 0 0 2 Low frequencies --- 52 103 107
HMim+ (a/b)
Item Table
Item Value Threshold Converged? Maximum Force 0.000019 0.000450 YES RMS Force 0.000005 0.000300 YES Maximum Displacement 0.000246 0.001800 YES RMS Displacement 0.000068 0.001200 YES
Low frequencies
Low frequencies --- -0.0006 -0.0004 0.0004 1.4614 3.5947 4.3281 Low frequencies --- 80.9935 248.1855 352.9294
Rounded to accurate significant figures:
Low frequencies --- 0 0 0 1 4 4 Low frequencies --- 81 248 353
HMim+ (c)
Item Table
Item Value Threshold Converged? Maximum Force 0.000003 0.000450 YES RMS Force 0.000001 0.000300 YES Maximum Displacement 0.000077 0.001800 YES RMS Displacement 0.000022 0.001200 YES
Low frequencies
Low frequencies --- -0.0010 -0.0003 0.0005 1.0236 2.4241 4.0797 Low frequencies --- 71.8861 73.8214 193.3113
Rounded to accurate significant figures:
Low frequencies --- 0 0 0 1 2 4 Low frequencies --- 72 74 193
Cl-
Item Table
Item Value Threshold Converged? Maximum Force 0.000000 0.000450 YES RMS Force 0.000000 0.000300 YES Maximum Displacement 0.000000 0.001800 YES RMS Displacement 0.000000 0.001200 YES
Low frequencies
Low frequencies --- -0.0066 -0.0066 -0.0066
Rounded to accurate significant figures:
Low frequencies --- 0 0 0
H-Cl bond distances
| Molecule/ion | HMim-Cl (a) | HMim-Cl (b) | HMim-Cl (c) |
| r(H-Cl) (Â) | 1.720 | 2.277 (Me-H-Cl) 2.134 (C-H-Cl) |
2.417 (Me-H-Cl) 2.030 (C-H-Cl) |
- The H-Cl bond of HMim-Cl (a) is a similar length to that of Me3NH-Cl (1.720Â vs 1.728Â respectively), while the H-Cl bonds in HMim-Cl (b), (c) are significantly longer than the Me3NH-Cl H-Cl bond (2.0-2.4$Acirc; vs 1.728$Acirc;).



