Conformational analysis and nitrogen inversion





Tinker scan (MMFF94) + crest (MF-MD-GC, GFN2-xTB) => DFT/PBE/L1


On figure(s) below click on the level title to download xyz file ==>
Click on energy level to view 3D structure in browser (run JSmol) ==>

0.00 0.00 0.03 0.03 0.16 0.16 0.35 0.35 0.56 0.56 0.75 0.75 0.75 0.75 0.89 0.89 0.92 0.92 0.96 0.96 1.15 1.15 1.21 1.21 1.25 1.25 1.25 1.25 1.27 1.27 1.40 1.40 1.56 1.56 1.65 1.65 1.70 1.70 1.73 1.73 1.85 1.85 1.89 1.89 2.13 2.13 2.24 2.24 2.26 2.26 2.34 2.34 2.48 2.48 2.54 2.54 2.60 2.60 2.60 2.60 2.62 2.62 2.64 2.64 2.69 2.69 2.70 2.70 2.76 2.76 2.84 2.84 2.85 2.85 2.85 2.85 2.94 2.94 2.97 2.97 2.99 2.99 3.01 3.01 3.03 3.03 3.13 3.13 3.15 3.15 3.16 3.16 3.18 3.18 3.20 3.20 3.21 3.21 3.22 3.22 3.29 3.29 3.32 3.32 3.36 3.36 3.47 3.47 3.47 3.47 3.49 3.49 3.61 3.61 3.66 3.66 3.68 3.68 3.68 3.68 3.71 3.71 3.73 3.73 3.74 3.74 3.74 3.74 3.78 3.78 3.78 3.78 3.86 3.86 3.91 3.91 3.95 3.95 3.98 3.98 3.99 3.99 4.01 4.01 4.04 4.04 4.05 4.05 4.08 4.08 4.08 4.08 4.14 4.14 4.14 4.14 4.17 4.17 4.18 4.18 4.24 4.24 4.25 4.25 4.26 4.26 4.30 4.30 4.46 4.46 4.47 4.47 4.47 4.47 4.47 4.47 4.50 4.50 4.54 4.54 4.54 4.54 4.57 4.57 4.58 4.58 4.59 4.59 4.59 4.59 4.64 4.64 4.64 4.64 4.66 4.66 4.67 4.67 4.69 4.69 4.71 4.71 4.78 4.78 4.86 4.86 4.88 4.88 5.01 5.01 5.01 5.01 5.01 5.01 5.06 5.06 5.10 5.10 5.15 5.15 5.17 5.17 5.17 5.17 5.17 5.17 5.19 5.19 5.24 5.24 5.28 5.28 5.33 5.33 5.37 5.37 5.41 5.41 5.42 5.42 5.45 5.45 5.46 5.46 5.47 5.47 5.48 5.48 5.49 5.49 5.52 5.52 5.52 5.52 5.53 5.53 5.55 5.55 5.57 5.57 5.58 5.58 5.64 5.64 5.67 5.67 5.70 5.70 5.72 5.72 5.75 5.75 5.75 5.75 5.77 5.77 5.88 5.88 5.89 5.89 5.89 5.89 5.96 5.96 6.01 6.01 6.03 6.03 6.05 6.05 6.07 6.07 6.14 6.14 6.27 6.27 6.31 6.31 6.33 6.33 6.34 6.34 6.41 6.41 6.45 6.45 6.45 6.45 6.59 6.59 6.62 6.62 6.66 6.66 6.73 6.73 6.77 6.77 6.79 6.79 6.82 6.82 6.94 6.94 6.96 6.96 7.07 7.07 7.08 7.08 7.13 7.13 7.17 7.17 7.18 7.18 7.23 7.23 7.24 7.24 7.26 7.26 7.30 7.30 7.32 7.32 7.38 7.38 7.39 7.39 7.50 7.50 7.58 7.58 7.65 7.65 7.72 7.72 7.72 7.72 7.73 7.73 7.73 7.73 7.74 7.74 7.75 7.75 7.82 7.82 7.87 7.87 7.91 7.91 7.94 7.94 7.96 7.96 7.97 7.97 7.99 7.99 8.04 8.04 8.05 8.05 8.10 8.10 8.14 8.14 8.43 8.43 8.54 8.54 8.63 8.63 8.65 8.65 8.71 8.71 8.88 8.88 8.90 8.90 8.92 8.92 9.07 9.07 9.87 9.87 9.92 9.92 11.40 11.40 17.06 17.06 17.13 17.13 18.39 18.39 18.58 18.58 22.02 22.02 22.08 22.08 22.36 22.36 22.68 22.68 23.79 23.79

Animation of vibration with imaginary frequency (-98 cm-1) for transition state RS.01-RSi.01


Extended view via JSmol (all frequencies and IRC path)

Synchronous nirtogen inversion and rotation around N-O bond

Conformational analysis and nitrogen inversion in other alkoxyamine



Tinker scan (MMFF94) => DFT/PBE/L1


0.00 0.00 0.26 0.26 0.33 0.33 0.40 0.40 0.47 0.47 0.75 0.75 0.76 0.76 0.91 0.91 1.11 1.11 1.28 1.28 1.57 1.57 2.02 2.02 2.15 2.15 2.18 2.18 2.29 2.29 2.29 2.29 2.32 2.32 2.44 2.44 2.50 2.50 2.59 2.59 2.60 2.60 2.62 2.62 2.66 2.66 2.82 2.82 2.88 2.88 3.01 3.01 3.09 3.09 3.11 3.11 3.18 3.18 3.21 3.21 3.25 3.25 3.27 3.27 3.28 3.28 3.29 3.29 3.31 3.31 3.32 3.32 3.43 3.43 3.44 3.44 3.54 3.54 3.58 3.58 3.59 3.59 3.59 3.59 3.63 3.63 3.63 3.63 3.64 3.64 3.65 3.65 3.65 3.65 3.66 3.66 3.79 3.79 3.80 3.80 3.83 3.83 4.04 4.04 4.04 4.04 4.06 4.06 4.06 4.06 4.08 4.08 4.12 4.12 4.13 4.13 4.13 4.13 4.19 4.19 4.20 4.20 4.26 4.26 4.31 4.31 4.35 4.35 4.36 4.36 4.36 4.36 4.41 4.41 4.43 4.43 4.44 4.44 4.44 4.44 4.47 4.47 4.59 4.59 4.60 4.60 4.69 4.69 4.77 4.77 4.78 4.78 4.80 4.80 4.80 4.80 4.92 4.92 4.92 4.92 4.94 4.94 4.95 4.95 4.96 4.96 4.96 4.96 5.03 5.03 5.04 5.04 5.07 5.07 5.08 5.08 5.10 5.10 5.15 5.15 5.24 5.24 5.28 5.28 5.45 5.45 5.49 5.49 5.52 5.52 5.60 5.60 5.62 5.62 5.72 5.72 5.73 5.73 5.84 5.84 5.87 5.87 5.87 5.87 5.89 5.89 5.90 5.90 5.90 5.90 5.99 5.99 6.12 6.12 6.16 6.16 6.16 6.16 6.24 6.24 6.34 6.34 6.37 6.37 6.55 6.55 6.59 6.59 6.65 6.65 6.71 6.71 6.77 6.77 6.84 6.84 6.92 6.92 6.97 6.97 7.06 7.06 7.10 7.10 7.11 7.11 7.19 7.19 7.33 7.33 7.40 7.40 7.64 7.64 7.70 7.70 7.71 7.71 7.73 7.73 7.83 7.83 7.89 7.89 7.90 7.90 8.05 8.05 8.09 8.09 8.12 8.12 8.12 8.12 8.14 8.14 8.20 8.20 8.36 8.36 8.37 8.37 8.57 8.57 8.59 8.59 8.68 8.68 8.70 8.70 8.74 8.74 9.05 9.05 9.96 9.96 10.52 10.52 11.03 11.03 11.84 11.84 20.63 20.63 21.19 21.19 24.12 24.12 24.54 24.54 26.29 26.29 27.21 27.21 28.22 28.22 28.27 28.27

More sterics - higher barrier

Sterically unhindered model 1‐methoxy‐2,5‐dihydroimidazole

0.00 0.00 0.00 0.00 5.29 5.29 9.71 9.71 10.46 10.46 13.21 13.21

Less sterics - lower barrier and stepwise inversion-rotation
07.04.2019