C12H9N




 





 






























Nitrogen


Nuclear Quadrupole Coupling Constants


in Carbazole


 








 








 








The microwave spectrum of carbazole, including determination of 14N diagonal quadrupole coupling constants, was investigated by Suenram et al. [1].

 








Calculation of the 14N nqcc tensor was made here on ropt molecular structures given by  B3LYP/cc-pVTZ and B3P86/6-31G(3d,3p) optimization (assuming C2V symmetry).  Calculated and experimental nqcc's are compared in Table 1.  Structure parameters are given in Table 2, rotational constants and electric dipole moments in Table 3.

 








In Table 1, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to principal axes of the nqcc tensor.

RMS is the root mean square difference between calculated and experimental diagonal nqcc's.  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 nqcc's in Carbazole (MHz).  Calculation was made on molecular structures given by (1) B3LYP/cc-pVTZ and (2) B3P86/6-31G(3d,3p) optimization.
   









Calc. (1)
Calc. (2)
Expt. [1]
   







Xaa(xx)
2.012
1.981
2.0697(40)

Xbb(yy)
1.981
1.989
1.8719(35)

Xcc(zz) -
 3.993
 -
 3.970
 -
 3.9416(35)










RMS
0.077 (2.9 %)
0.087 (3.3 %)



RSD
0.030 (1.3 %)
0.030 (1.3 %)



 








 








 







 
 

Table 2.  Carbazole.  Optimized molecular structure parameters, ropt (Å and degrees).
 

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




 C
 C,1,B1
 C,2,B2,1,A1
 C,3,B3,2,A2,1,D1,0
 C,4,B4,3,A3,2,D2,0
 C,5,B5,4,A4,3,D3,0
 H,1,B6,2,A5,3,D4,0
 H,2,B7,1,A6,6,D5,0
 H,3,B8,2,A7,1,D6,0
 H,6,B9,5,A8,4,D7,0
 N,4,B10,3,A9,2,D8,0
 H,11,B11,4,A10,3,D9,0
 C,11,B12,4,A11,3,D10,0
 C,13,B13,11,A12,4,D11,0
 C,14,B14,13,A13,11,D12,0
 C,15,B15,14,A14,13,D13,0
 C,16,B16,15,A15,14,D14,0
 C,17,B17,16,A16,15,D15,0
 H,14,B18,13,A17,11,D16,0
 H,15,B19,14,A18,13,D17,0
 H,16,B20,15,A19,14,D18,0
 H,17,B21,16,A20,15,D19,0


      B3LYP
         B3P86


 B1=1.40056184
 B2=1.38722327
 B3=1.3914958
 B4=1.41579887
 B5=1.39488282
 B6=1.08137644
 B7=1.08183435
 B8=1.08216123
 B9=1.08219966
 B10=1.38239082
 B11=1.00323812
 B12=1.38239082
 B13=1.3914958
 B14=1.38722327
 B15=1.40056184
 B16=1.38649498
 B17=1.39488282
 B18=1.08216123
 B19=1.08183435
 B20=1.08137644
 B21=1.08219966
 A1=121.31962938
 A2=117.71733663
 A3=121.80873844
 A4=119.20769358
 A5=119.44789312
 A6=119.42117302
 A7=120.92297317
 A8=120.49104268
 A9=129.68314954
 A10=125.19417358
 A11=109.61165283
 A12=129.68314954
 A13=117.71733663
 A14=121.31962938
 A15=120.7285098
 A16=119.21809218
 A17=121.3596902
 A18=119.25919759
 A19=119.44789312
 A20=120.29086514
 D1=0.
 D2=0.
 D3=0.
 D4=180.
 D5=180.
 D6=180.
 D7=180.
 D8=180.
 D9=0.
 D10=180.
 D11=180.
 D12=180.
 D13=0.
 D14=0.
 D15=0.
 D16=0.
 D17=180.
 D18=180.
 D19=180.
  B1=1.40052118
 B2=1.38720314
 B3=1.39146332
 B4=1.41528709
 B5=1.39510743
 B6=1.08444611
 B7=1.08492691
 B8=1.0850156
 B9=1.08516304
 B10=1.37978007
 B11=1.00492795
 B12=1.37978007
 B13=1.39146332
 B14=1.38720314
 B15=1.40052118
 B16=1.38646476
 B17=1.39510743
 B18=1.0850156
 B19=1.08492691
 B20=1.08444611
 B21=1.08516304
 A1=121.40198595
 A2=117.57240279
 A3=121.90668103
 A4=119.23786993
 A5=119.43103726
 A6=119.39431766
 A7=121.00399532
 A8=120.48039073
 A9=129.56198681
 A10=125.18578851
 A11=109.62842297
 A12=129.56198681
 A13=117.57240279
 A14=121.40198595
 A15=120.75824526
 A16=119.12281503
 A17=121.42360189
 A18=119.20369639
 A19=119.43103726
 A20=120.39679424
 D1=0.
 D2=0.
 D3=0.
 D4=180.
 D5=180.
 D6=180.
 D7=180.
 D8=180.
 D9=0.
 D10=180.
 D11=180.
 D12=180.
 D13=0.
 D14=0.
 D15=0.
 D16=0.
 D17=180.
 D18=180.
 D19=180.





 














Table 3.  Carbazole.  Rotational Constants (MHz) and Dipole Moments * (D).







ropt(1) = B3LYP/cc-pVTZ optimization.

ropt(2) = B3P86/6-31G(3d,3p) optimization.








ropt(1) ropt(2) Expt [1]







A
 2273.0
 2272.4
 2253.1985(2)

B
   595.5
   596.5
   594.1861(2)

C
   471.9
   472.4
   470.3503(1)







|µb|   1.66
   1.68


 




* B3PW91/6-311+G(df,pd) dipole moment calculation on ropt structures.













 








[1] R.D.Suenram, F.J.Lovas, G.T.Fraser, and P.S.Marfey, J.Mol.Struct. 190,135(1988).

 








 








Pyrrole
Pyrazole
 Imidazole
 Indole

 








 








Table of Contents




Molecules/Nitrogen




 








 













carbazole.html






Last Modified 12 Dec 2013