B3LYP/6-31G* Methoda Exp.b,c
Parameter C1 C2 C3  
Bond Length (Å)
C1=C2 1.390 1.389 1.389 1.366
C2=C3 1.411 1.411 1.412 1.394
C3=C4 1.393 1.393 1.394 1.380
C4=N5 1.373 1.375 1.376 1.369
N5=C1 1.361 1.360 1.360 1.349
C1-C9 1.486 1.492 1.492  
C4 -C13 1.466 1.464 1.465 1.445
C13 -C14 1.516 1.516 1.516 1.500
N5 –H6 1.011 1.011 1.012 0.914
C13=O18 1.227 1.228 1.228 1.227
C9 –F11 1.373 1.364 1.374 1.371c
C9 – F12 1.372 1.374 1.365 1.372c
C9 –H10 1.094 1.096 1.097 1.000
C14 –H15 1.091 1.091 1.091 0.965
C14 –H16 1.096 1.096 1.096 0.999
C14 –H17 1.096 1.096 1.096 0.932
C2 –H7 1.081 1.080 1.081 0.981
C3 -H8 1.081 1.081 1.082 0.949
RMSD 0.019 0.019 0.019  
Bond angle (degrees)
H10-C9-F11 107.9 107.4 106.9 110.5c
H10-C9-F12 108.8 106.9 107.4 110.5c
F11-C9-F12 106.6 109.0 109.0 105.8c
H10-C9-C1 112.5 114.3 114.3 110.5
F11-C9-C1 111.2 109.8 109.3 109.4c
F12-C9-C1 109.6 109.3 109.8 110.0c
C9-C1-C2 130.3 130.3 130.3  
C9-C1-N5 121.6 121.4 121.4  
C1-C2-H7 125.7 125.5 125.5 127.4
C1-C5-H6 127.3 127.3 127.3 123.0
H7-C2-C3 127.1 127.5 127.5 125.2
H6-N5-C4 122.6 122.6 122.6 127.5
H8-C3-C4 125.9 125.8 125.8 126.0
C3-C4-C13 134.0 134.2 134.2 131.4
N5-C4-C13 118.7 118.6 118.6 121.6
C4-C13-O18 119.8 119.8 119.8  
C4-C13-C14 118.1 118.1 118.1 118.2
O18-C13-C14 122.1 122.1 122.1  
C13-C14-H15 109.1 109.0 109.0 110.6
C13-C14-H16 110.7 110.7 110.8 112.5
C13-C14-H17 110.8 110.8 110.7 113.9
RMSD 0.6 0.7 0.7  
C2-C1-C9-H10 -24.948 -86.535 86.432  
C2-C1-C9-F11 96.212 34.246 -153.825  
C2-C1-C9-F12 -146.189 153.72855 -34.338  
N5-C1-C9-H10 158.823 88.725 -88.814  
N5-C1-C9-F11 -80.015 -150.494 30.928  
N5-C1-C9-F12 37.582 -31.011 150.415  
C3-C4-C13-O18 178.794 -179.148 179.121  
N5-C4-C13-O18 -0.279 0.006 0.011  
C4-C13-C14-H15 179.290 179.004 -178.858  
C4-C13-C14-H16 -60.267 -60.588 -58.234  
C4-C13-C14-H17 58.702 58.397 60.751  
O18-C13-C14-H15 -0.806 -1.064 1.223  
O18-C13-C14-H16 119.635 119.344 121.847  
O18-C13-C14-H17 -121.394 -121.671 -119.168  
H6-N5-C4-C13 1.492 -2.912 2.859 0.31
H8-C3-C4-C13 0.797 -0.754 0.798 1.88
Table 1: Comparison of calculated geometrical parameters with the corresponding experimental values for the conformers of 1-(5-(difluoromethyl)-1H-pyrrol-2-yl) ethanone.