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.  Ø (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



Øz,a
  2.31

  2.66




Øa,N=C
21.38

22.94




Øz,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 (Å 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