1H-Pyrrole-2-carbonitrile





















































Nitrogen


Nuclear Quadrupole Coupling Constants


in  1H-Pyrrole-2-carbonitrile


 








 








 

 





The microwave spectrum of pyrrole-2-carbonitrile was investigated by Davis and Gerry [1] (1980), and by Sakaizumi et al. [2] (1991).

 








Calculation of the 14N nqcc tensors was made here on ropt molecular structures given by B3LYP/cc-pVTZ and B3P86/6-31G(3d,3p) optimizations.  These calculated nqcc's are given in Tables 1 and 2.  Structure parameters in Z-matrix format are compared in Table 3, rotational constants in Table 4.  Dipole moments and quartic centrifugal distortion constants are given in Table 5.

 








In Tables 1 and 2, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

RSD is the calibration residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of nitrogen efg's/nqcc's.

 








 








 








Table 1.  14N (Pyrrolic) nqcc's in Pyrrole-2-carbonitrile (MHz).  Calculation was made on the B3LYP/cc-pVTZ and B3P86/6-31G(3d,3p) ropt structures.
 










Calc /B3LYP
Calc /B3P86
Expt.
 








Xaa
1.261
1.232



Xbb
1.473
1.474



Xcc - 2.734 -
 2.706



|Xab|
0.162
0.146












RSD
0.030 (1.3 %)
0.030 (1.3 %)












Xxx
1.174
1.163



Xyy
1.560
1.542



Xzz - 2.734 -
 2.706



ETA
0.141
0.140



Øz,c
   0
   0













 








 








 








Table 2.  14N (Cyanic) nqcc's in Ptrrole-2-carbonitrile (MHz).  Calculation was made on the B3LYP/cc-pVTZ and B3P86/6-31G(3d,3p) ropt structures.
 










Calc /B3LYP
Calc /B3P86
Expt
 








Xaa -
 4.203
 -
 4.145



Xbb
2.833
2.817



Xcc
1.370
1.328



|Xab|
0.299
0.306












RSD
0.030 (1.3 %)
0.030 (1.3 %)












Xxx
2.846
2.830



Xyy
1.370
1.328



Xzz -
 4.216
 -
 4.158



ETA
0.350
0.361



Øz,a
2.43
2.51



Øa,CN
2.52
2.59



Øz,CN
0.09
0.08













 








 







 
 


Table 3. Ptrrole-2-carbonitrile (MHz).  B3LYP/cc-pVTZ and B3P86/6-31G(3d,3p) ropt structure parameters (Å and degrees).





 C
 C,1,B1
 C,2,B2,1,A1
 C,3,B3,2,A2,1,D1,0
 N,1,B4,2,A3,3,D2,0
 H,5,B5,1,A4,2,D3,0
 H,1,B6,5,A5,4,D4,0
 H,2,B7,1,A6,5,D5,0
 H,3,B8,2,A7,1,D6,0
 C,4,B9,3,A8,2,D7,0
 N,10,B10,5,A9,1,D8,0





B3LYP/cc-pVTZ
 B3P86/6-31G(3d,3p)





 B1=1.37840861
 B2=1.41029885
 B3=1.38368175
 B4=1.3606205
 B5=1.00466819
 B6=1.07561793
 B7=1.07587937
 B8=1.07581057
 B9=1.40980669
 B10=1.15467711
 A1=107.51195667
 A2=107.32682339
 A3=108.18668725
 A4=125.93394597
 A5=121.11588983
 A6=125.774495
 A7=127.52066436
 A8=130.56706001
 A9=150.86619732
 D1=0.
 D2=0.
 D3=180.
 D4=180.
 D5=180.
 D6=180.
 D7=180.
 D8=180.
  B1=1.37964472
 B2=1.40928491
 B3=1.3845855
 B4=1.35813566
 B5=1.00658589
 B6=1.07874658
 B7=1.07916386
 B8=1.07902831
 B9=1.40922916
 B10=1.16001267
 A1=107.48197674
 A2=107.21719094
 A3=108.19392459
 A4=125.9859573
 A5=120.92788952
 A6=125.71651382
 A7=127.73612063
 A8=130.64701698
 A9=150.74879061
 D1=0.
 D2=0.
 D3=180.
 D4=180.
 D5=180.
 D6=180.
 D7=180.
 D8=180.







 








 



Table 4. Ptrrole-2-carbonitrile (MHz).  B3LYP/cc-pVTZ and B3P86/6-31G(3d,3p) ropt Rotational Constants (MHz).







B3LYP
 B3P86
   Expt [1]






A
  9006
  9000
8946.6297(88)

B
  1998
  1998
 1988.5936(21)

C
  1635
  1635
 1626.5440(16)


 


















 




Table 5. Ptrrole-2-carbonitrile (MHz).  B3LYP/cc-pVTZ Quartic Centrifugal Distortion Constants (kHz) and Dipole Moments (D).









B3LYP
Expt [1]







Delta_J
0.0718
0.0690(26)

Delta_JK
2.62
2.812(11)

Delta_K
0.108
  ----

delta_J
0.0138
0.0169(26)

delta_K
1.48
1.26(10)







|µa|
4.19


|µb|
1.54























[1] R.W.Davis and M.C.L.Gerry, J.Phys.Chem. 84,1767(1980).

[2] T.Sakaizumi, M.Oka, S.Miyake, O.Ohashi, I.Yamaguchi, J.Mol.Spectrosc. 147,229(1991).

 








 








Pyrrole Pyrazole
 Imidazole



Benzonitrile





 








 








Table of Contents




Molecules/Nitrogen




 








 













2CNPyrrole.html






Last Modified 13 Feb 2014