CH3CH2N=C=S































 









Nitrogen


Nuclear Quadrupole Coupling Constants


in Methylisothiocyanate


 








 









Calculation was made of the 14N nqcc tensor in ethylisothiocyanate on ropt structures given by B3LYP/6-311+G(3df,3pd) and MP2/6-311+G(3df,3pd) optimization. 












In Table 1, these calculated nqcc's are compared with the experimental values of Kasten et al. [1].  Subscripts a,b,c refer to the principal axes of the inertia tensor.  Subscripts x,y,z refer to the principal axes of the nqcc tensor.  (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.  RMS is the root mean square difference between calculated and experimental 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.  

Structure parameters are given in Z-matrix format in Table 2, rotational constants and dipole moments in Table 3.


 








 









   








Table 1.  14N nqcc's in CH3CH2N=C=S (MHz).  Calculation was made on ropt molecular structures given by B3LYP/6-311+G(3df,3pd) and MP2/6-311+G(3df,3pd) optimization.

   










Calc. B3LYP
Calc. MP2

Expt. [1]
   








Xaa
1.939
1.998
1.873(18)


Xbb - 1.178 - 1.241 -
1.264(26)


Xcc - 0.761 - 0.757 -
0.609(26)


|Xab|
0.126
0.150



 








RMS

0.108 (8.6 %)

0.113 (9.0 %)




RSD
0.030 (1.3 %)
0.030 (1.3 %)



 







Xxx - 1.183 - 1.248




Xyy - 0.761 - 0.757



Xzz
1.944
2.005



ETA -
0.217 -
0.245



z,a
  2.31

  2.66




a,N=C
21.38

22.94




z,N=C
19.07

20.28




 








 

















 

 






Table 2.  CH3CH2N=C=S.  B3LYP/6-311+G(3df,3pd) and MP2/6-311+G(3df,3pd) optimized structure parameters ( and degrees).

 









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













   B3LYP
   MP2


 B1=1.52628014
 B2=1.43060538
 B3=1.18335138
 B4=1.58475565
 B5=1.09015337
 B6=1.08908937
 B7=1.08908937
 B8=1.09151973
 B9=1.09151973
 A1=112.79925174
 A2=152.52348924
 A3=176.32150916
 A4=109.55985779
 A5=110.85456412
 A6=110.85456412
 A7=110.57390671
 A8=110.57390671
 D1=0.
 D2=180.
 D3=180.
 D4=-60.29943195
 D5=60.29943195
 D6=120.98677108
 D7=-120.98677108
 B1=1.52014181
 B2=1.43178128
 B3=1.19865319
 B4=1.57870605
 B5=1.08866676
 B6=1.08766744
 B7=1.08766744
 B8=1.08955467
 B9=1.08955467
 A1=111.3582747
 A2=148.18174951
 A3=175.48503895
 A4=109.84903716
 A5=110.38084301
 A6=110.38084301
 A7=110.98952562
 A8=110.98952562
 D1=0.
 D2=180.
 D3=180.
 D4=-60.04508911
 D5=60.04508911
 D6=120.28421843
 D7=-120.28421843




 








 













Table 3.  CH3CH2N=C=S.  Rotational Constants (MHz) and Dipole Moments (D).







B3LYP
 MP2
Expt [1,2]






A
 15181.
14347.
14188.5(54)  [1]

B
   1711.
  1773.
  1779.274(6)

C
   1567.
  1609.
  1612.130(6)






|a|
  3.82
  3.54
3.33(3)  [2]

|b|   0.006
  0.15
0.07(2)

|c|   0 (symm)
  0 (symm)




 









 









[1] W.Kasten, H.Dreizler, and R.Schwarz, Z.Naturforsch. 38a,585(1983).


[2] T.Sakaizumi, O.Ohashi, I.Yamaguchi, Bull.Chem.Soc.Jpn. 49(4).948(1976).






















HNCS

CH3NCS
(CH3)3CNCS
Phenyl-NCS


 


















Table of Contents




Molecules/Nitrogen




 








 













CH3CH2NCS.html






Last Modified 9 Jan 2016