C3H4N2O2



















 




 








Nitrogen

Nuclear Quadrupole Coupling Constants

in Imidazolidine-2,4-dione (Hydantoin)

 







 








 








Nitrogen nqcc's in hydantoin were determined by Alonso, et al. [1].

 








Calculation of the nitrogen nqcc tensors in hydantoin was made here on an ropt structure given by B3LYP/cc-pVTZ optimization.  These calculated nqcc's are compared with the experimental values in Tables 1 and 2.  Structure parameters are given in Z-matrix format in Table 3, rotational constants in Table 4.

 








Calculation of the efg's/nqcc's was made with both B3PW91/6-311+G(df,pd) and B3PW91/6-311+G(d,p) models, the latter shown to perform better than the former for modeling conjugated pi-electron systems [2].

 








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.  ETA = (Xxx - Xyy)/Xzz.  RMS is the root mean square difference between calculated and experimental diagonal nqcc's (percentage of the average of the magnitudes of the experimental nqcc's).  RSD is the calibration residual standard deviation of the model for calculation of nitrogen efg's/nqcc's.



 








 








   







Table 1.  14N(1) nqcc's in Hydantoin (MHz).  Calculation was made on the ropt molecular structure with (1) B3PW91/6-311+G(df,pd) and (2) B3PW91/6-311+G(d,p) models.
   









Calc (1)
Calc (2)
Expt [1]
   







Xaa
2.655
2.722
2.5900(41)

Xbb
2.225
2.322
2.1438(70)

Xcc -
 4.880
 -
 5.044
 -
 4.7338(70)

|Xab|
0.207
0.204



 







RMS
0.104 (3.3 %)
0.220 (7.0%)



RSD
0.030 (1.3 %)
0.086 (3.8 %)


 







Xxx
2.738
2.808



Xyy
2.142
2.236



Xzz -
 4.880 -
 5.044



ETA -
 0.122
 -
 0.113



 








 








 







   







Table 2.  14N(3) nqcc's in Hydantoin (MHz).  Calculation was made on the ropt molecular structure with (1) B3PW91/6-311+G(df,pd) and (2) B3PW91/6-311+G(d,p) models.
   









Calc (1)
Calc (2)
Expt [1]
   







Xaa
1.607
1.679
1.6315(51)

Xbb
1.779
1.858
1.8321(75)

Xcc -
 3.386
 -
 3.536
 -
 3.4635(75)

|Xab|
0.076
0.073



 







RMS
0.056 (2.4 %)
0.052 (2.3 %)



RSD
0.030 (1.3 %)
0.086 (3.8 %)


 







Xxx
1.578
1.653



Xyy
1.808
1.883



Xzz -
 3.386
 -
 3.536



ETA
0.0679
0.0653



 








 








 














Table 3.  Hydantoin.  Structure parameters, ropt = B3LYP/cc-pVTZ (Å and degrees).
 








 N
 C,1,B1
 N,2,B2,1,A1
 C,3,B3,2,A2,1,D1,0
 H,1,B4,2,A3,3,D2,0
 O,2,B5,1,A4,4,D3,0
 H,3,B6,2,A5,1,D4,0
 O,4,B7,3,A6,2,D5,0
 C,1,B8,2,A7,6,D6,0
 H,9,B9,1,A8,2,D7,0
 H,9,B10,1,A9,2,D8,0









 B1=1.3665913
 B2=1.4094302
 B3=1.3750941
 B4=1.00330429
 B5=1.20586036
 B6=1.00648988
 B7=1.20427321
 B8=1.44738042
 B9=1.09197362
 B10=1.09197362
 A1=105.28084324
 A2=113.68550985
 A3=120.80025879
 A4=128.71325661
 A5=122.0769678
 A6=127.54919904
 A7=113.35514827
 A8=113.36904371
 A9=113.36904371
 D1=0.
 D2=180.
 D3=180.
 D4=180.
 D5=180.
 D6=180.
 D7=117.89506202
 D8=-117.89506202








 








 












Table 4.  Hydantoin.  Rotational Constants (MHz).






ropt     Expt [1]





A
 6568.
 6537.73799(86)

B
 2287.
 2291.37278(16)

C
 1715.
 1716.47204(22)



 








 








[1] E.R.Alonso, L.Kolesniková, and J.L.Alonso, J.Chem.Phys. 147,124312(2017).

[2] R.Kannengießer, W.Stahl, H.V.L.Nguyen, and W.C.Bailey, J.Mol.Spectrosc. 317,50(2015).

 








H.Ozeki, R.Miyahara, H.Ihara, S.Todaka, K.Kobayashi, and M.Ohishi, Abstract TH10, 71st International Symposium on Molecular Spectroscopy, Champaign-Urbana, Ill 2016.

Ibid, A&A 600,A44(2017).

 








 








Imidazole
 Uracil
 Thymine 2-Pyridone

N-Vinylformamide
 N-Methyldiacetamide
Maleimide

 








 








Table of Contents




Molecules/Nitrogen




 








 













Hydantoin.html






Last Modified 29 Sept 2017