C3H5SiH2CN






 








 








Nitrogen


Nuclear Quadrupole Coupling Constants


in Cyclopropyl Cyanosilane



 


















Nitrogen nqcc's in the following cis and gauche conformers of cyclopropyl cyanosilane were determined by Seifert et al. [1]. 












cis (Cs)

gauche (C1)








































 








Calculation of the nitrogen nqcc tensors in each conformer was made here on molecular ropt structures given by B3P86/6-31G(3d,3p) and mPW1PW91/6-31G(3d,3p) optimization.  Calculated and experimental nqcc's are compared in Tables 1and 2.  Structure parameters are given in Z-matrix format in Table 3, rotational constants in Table 4.

 








In Tables 1 and 2, subscripts a,b,c refer to the principal axes of the inertia tensor, subscripts x,y,z to the principal axes of the nqcc tensor.   ETA = (Xxx - Xyy)/Xzz.  (degrees) is the angle between its subscripted parameters.  RMS is the root measn square difference between calculated and experimental diagonal nqcc's.  RSD is the residual standard deviation of calibration of the B3PW91/6-311+G(df,pd)  model for calculation of the efg's/nqcc's.

 








 








   








Table 1.  14N nqcc's in cis Cyclopropyl Cyanosilane (MHz).  Calculation was made on molecular structures given by (1) B3P86/6-31G(3d,3p) and (2) mPW1PW91/6-31G(3d,3p) optimization.
   










Calc (1)

Calc (2)

Expt. [1] *

 








Xaa
-
0.103
-
0.117
-
0.1177(59)


Xbb -
2.363
-
2.354
-
2.3345(53)


Xcc
2.466

2.471

2.4523(53)


Xab
3.677

3.690




 








RMS

0.020 (1.2 %)

0.016 (0.97 %)




RSD
0.030 (1.3 %)
0.030 (1.3 %)


 







Xxx
2.614

2.620




Xyy
2.466
2.471



Xzz -
5.080
-
5.091




ETA -
0.0291
-
0.0292




z,a
53.54

53.43




a,CN
53.88

53.78




z,CN
  0.34

  0.35














 








* Calculated here from 1.5(Xaa) = -0.1766(88) and 0.25(Xbb - Xcc) = -1.1967(22) MHz.

 









 









   








Table 2.  14N nqcc's in gauche Cyclopropyl Cyanosilane (MHz).  Calculation was made on molecular structures given by (1) B3P86/6-31G(3d,3p) and (2) mPW1PW91/6-31G(3d,3p) optimization.
   










Calc (1)

Calc (2)

Expt. [1] *

 








Xaa
-
2.778
-
2.788
-
2.701(9)


Xbb
0.271

0.275

0.211(11)


Xcc
2.507

2.513

2.490(11)


Xab
3.461
-
3.467




Xac
0.436

0.436




Xbc -
0.235

0.235




 








RMS

0.057 (3.2 %)

0.064 (3.5 %)




RSD
0.030 (1.3 %)
0.030 (1.3 %)


 







Xxx
2.575

2.581




Xyy
2.493

2.499




Xzz -
5.068
-
5.080




ETA
0.0162

0.0161




z,CN
0.12

0.11














 









* Calculated here from 1.5(Xaa) = -4.052(14) and 0.25(Xbb - Xcc) = -0.5698(49) MHz.

 









 









 




Table 3. Cyclopropyl Cyanosilane.  B3P86/6-31G(3d,3p) and mPW1PW91/6-31G(3d,3p) optimized structure parameters ( and degrees).
 





cis Cyclopropyl Cyanosilane









 C
 C,1,B1
 C,2,B2,1,A1
 H,1,B3,2,A2,3,D1,0
 H,2,B4,1,A3,3,D2,0
 H,2,B5,1,A4,3,D3,0
 H,3,B6,2,A5,1,D4,0
 H,3,B7,2,A6,1,D5,0
 Si,1,B8,2,A7,3,D6,0
 H,9,B9,1,A8,2,D7,0
 H,9,B10,1,A9,2,D8,0
 C,9,B11,1,A10,2,D9,0
 N,12,B12,9,A11,1,D10,0









      B3P86   mPW1PW91










 B1=1.51434544
 B2=1.49039794
 B3=1.08773916
 B4=1.0835398
 B5=1.08472477
 B6=1.08472477
 B7=1.0835398
 B8=1.84229726
 B9=1.47816639
 B10=1.47816639
 B11=1.85166783
 B12=1.15863092
 A1=60.52175075
 A2=114.91007488
 A3=117.06383777
 A4=118.32616304
 A5=117.71852488
 A6=118.50968256
 A7=121.39922998
 A8=113.36320678
 A9=113.36320678
 A10=107.10486114
 A11=177.4074877
 D1=105.21912214
 D2=-109.08028992
 D3=107.59431447
 D4=108.5843395
 D5=-106.72181861
 D6=-110.18380538
 D7=-81.91725313
 D8=152.32954589
 D9=35.20614638
 D10=0.
 B1=1.51357344
 B2=1.48974208
 B3=1.08705639
 B4=1.0829037
 B5=1.08402418
 B6=1.08402418
 B7=1.0829037
 B8=1.84355909
 B9=1.47913251
 B10=1.47913251
 B11=1.85368019
 B12=1.15696855
 A1=60.51949114
 A2=114.92923994
 A3=117.02116153
 A4=118.34669295
 A5=117.74285526
 A6=118.47763125
 A7=121.4305515
 A8=113.34336879
 A9=113.34336879
 A10=107.20887021
 A11=177.42628096
 D1=105.23420962
 D2=-109.05906622
 D3=107.61426609
 D4=108.59804886
 D5=-106.68274794
 D6=-110.21164949
 D7=-81.91453071
 D8=152.35946954
 D9=35.22246941
 D10=0.


 





 





gauche Cyclopropyl Cyanosilane








 C
 C,1,B1
 C,2,B2,1,A1
 H,1,B3,2,A2,3,D1,0
 H,2,B4,1,A3,3,D2,0
 H,2,B5,1,A4,3,D3,0
 H,3,B6,2,A5,1,D4,0
 H,3,B7,2,A6,1,D5,0
 Si,1,B8,2,A7,3,D6,0
 H,9,B9,1,A8,2,D7,0
 H,9,B10,1,A9,2,D8,0
 C,9,B11,1,A10,2,D9,0
 N,12,B12,1,A11,9,D10,0









      B3P86   mPW1PW91








 B1=1.51338575
 B2=1.48993982
 B3=1.08657386
 B4=1.08341275
 B5=1.08472588
 B6=1.08498375
 B7=1.08343902
 B8=1.83931679
 B9=1.477847
 B10=1.47938242
 B11=1.85113806
 B12=1.15847136
 A1=60.67019268
 A2=115.16291264
 A3=116.98178696
 A4=118.42355626
 A5=118.12862134
 A6=118.52059465
 A7=120.37025103
 A8=113.4310095
 A9=110.17629106
 A10=110.27751387
 A11=144.34788552
 D1=105.25087772
 D2=-109.05863285
 D3=108.21014283
 D4=108.57495764
 D5=-106.64598969
 D6=-108.05454463
 D7=158.50281202
 D8=34.19464919
 D9=-83.0734243
 D10=179.52741074
 B1=1.51277557
 B2=1.48927353
 B3=1.08587952
 B4=1.08273138
 B5=1.08402543
 B6=1.08427856
 B7=1.08276785
 B8=1.84057018
 B9=1.47864022
 B10=1.4801979
 B11=1.85279531
 B12=1.15682708
 A1=60.664694
 A2=115.16704634
 A3=116.96539204
 A4=118.41443378
 A5=118.12242264
 A6=118.49611676
 A7=120.35134591
 A8=113.40098323
 A9=110.24473908
 A10=110.28767458
 A11=144.39698396
 D1=105.28299302
 D2=-109.03255348
 D3=108.201219
 D4=108.57846189
 D5=-106.62393831
 D6=-108.06910021
 D7=158.48475601
 D8=34.18938953
 D9=-83.11769605
 D10=179.53508545


 






 









 




Table 4.  Cyclopropyl Cyanosilane Rotational Constants (MHz).  Calc = (1) B3P86/6-31G(3d,3p) and (2) mPW1PW91/6-31G(3d,3p) optimized molecular structures.







Calc (1)
Calc (2)
    Expt. [1]





   cis A
  4433.
  4439.
4387.40278(84)

B
  2161.
  2156.
2196.50693(68)

C
  1670.
  1667.
1684.73866(60)





   gauche A
  7150.
  7161.
7029.7244(45)

B
  1545.
  1543.
1567.1001(48)

C
  1365.
  1364.
1377.7489(45)



  








[1] N.A.Seifert, S.Lobsiger, B.H.Pate, G.A.Guirgis, J.S.Overby, J.R.Durig, and P.Groner, 69th International Symposium on Molecular Spectroscopy, Champaign-Urbana, Ill. 2014.


 









J.R.Durig, G.A.Guirgis, D.K.Sawant, N.A.Seifert, B.S.Deodhar, B.H.Pate, S.S.Panikar, P.Groner, J.S.Overby, S.M.Askarian, Chem.Phys. 445,68(2014).

 









 









SiH3CN
SiF3CN












 








Table of Contents




Molecules/Nitrogen




 








 













cyclopropyl_SiH2CN.html






Last Modified 4 Feb 2016