CH3SCN




 









Nitrogen and Sulfur


Nuclear Quadrupole Coupling Constants


in Methyl Thiocyanate


 








 








 








   









Table 1. Nitrogen nqcc's in CH332SCN (MHz).  Calculation was made on the substitution structure given below.

   












Calc.
Expt. [1]
Expt. [3]
   









14N Xaa - 3.062 - 3.20(9) -
3.13(5)



Xbb
2.124
2.02(9)
2.19(5)



Xcc
0.938
1.18(9)
0.94(5)



|Xab|
2.266





 









RMS


0.17 (8.0 %)
0.055 (2.6 %)


RSD
0.030 (1.3 %)





 









 









 









   







Table 2. Nitrogen nqcc's in CH333SCN (MHz).  Calculation was made on the substitution structure given below.

   










Calc.
Expt. [2]
   







14N Xaa - 3.080 - 3.227(4)


Xbb
2.142
2.067(6)


Xcc
0.938
1.160(7)


|Xab|
2.245



 







RMS
0.160 (7.4 %)




RSD
0.030 (1.3 %)



 







 








 







 
   








Table 3.  33S nqcc's in CH333SCN (MHz).  Calculation was made on the substitution structure given below.

 







  Calc [a] B3LYP/6-311G(3df,3p)

  Calc [b] B3LYP/TZV+(3df,3p)

 









Calc. [a]

Calc. [b]
Expt. [2]
   








Xaa - 39.81 - 40.06 - 40.513(4)

Xbb
- 7.03
- 6.82
- 7.166(6)

Xcc
46.84
46.88
47.679(7)

|Xab|
  4.96
  4.75



 







RMS
0.64 (2.0 %)
0.57 (1.8 %)



RSD
0.39 (1.7 %)
0.35 (1.5 %)



 








 








 











Table 4.  Molecular structure parameters rs [4] ( and degrees minutes).



H* lies in CSCN plane. SC* 1.6842(30)
C* is cyano carbon. C*N 1.1697(20)

CS 1.8237(21)

CH* 1.0725(15)

CH 1.0855(43)

CSC* 99 2'(5')

H*CH 110 15'(14')

HCH 111 17'(7')

H*CS 105 25'(15')

HCS 109 44'(8')


 
















Substitution Coordinates











  a ()
  b ()
  c ()









S - 0.5777(24) - 0.6289(20)
0.0

C*
0.9974(3) - 0.0326(170)
0.0

N
2.0922(1)
0.3791(5)
0.0

C - 1.4832(1)
0.9541(2)
0.0

H* - 2.5222(12)
0.6881(40)
0.0

H - 1.2393(25)
1.5160(18) 0.8961(38)


 








The sensitivity of the calculated nqcc's to the large uncertainty in the b-coordinate of the cyano carbon is seen in the following Tables.  Calculation was made on the structure obtained with b(C*) = - 0.0326 + 0.0170 = - 0.0156 , in which case SC* = 1.6903  and C*N = 1.1638 .

 








 








   









Table 5. Nitrogen nqcc's in CH332SCN (MHz).  Calculation was made on a structure given by the substitution coordinates above but with b(C*) = - 0.0156 .
   












Calc.
Expt. [1]
Expt. [3]

   









14N Xaa - 3.142 - 3.20(9) -
3.13(5)



Xbb
2.130
2.02(9)
2.19(5)



Xcc
1.012

1.18(9)
0.94(5)



|Xab|
2.258





 









RMS


0.12 (5.7 %)
0.055 (2.6 %)


RSD
0.030 (1.3 %)





 









 









 









   







Table 6. Nitrogen nqcc's in CH333SCN (MHz).  Calculation was made on a structure given by the substitution coordinates above but with b(C*) = - 0.0156 .
   










Calc.
Expt. [2]
   







14N Xaa - 3.160 - 3.227(4)


Xbb
2.148
2.067(6)


Xcc
1.012
1.160(7)


|Xab|
2.237



 







RMS
0.105 (4.9 %)




RSD
0.030 (1.3 %)



 







 








 








   








Table 7.  33S nqcc's in CH333SCN (MHz).  Calculation was made on a structure given by the substitution coordinates above but with b(C*) = - 0.0156 .

 







  Calc [a] B3LYP/6-311G(3df,3p)

  Calc [b] B3LYP/TZV+(3df,3p)

 









Calc. [a]

Calc. [b]
Expt. [2]
   








Xaa - 40.18 - 40.42 - 40.513(4)

Xbb
- 7.18
- 6.98
- 7.166(6)

Xcc
47.36
47.40
47.679(7)

|Xab|
  4.40
  4.18



 







RMS
0.26 (0.83 %) 0.20 (0.62 %)


RSD
0.39 (1.7 %) 0.35 (1.5 %)


 








 







   








[1] H.Dreizler, Z.Naturforsch. 21a,2101-L(1966).

[2] N.Hansen, H.Hartwig, U.Kretschmer, and H.Mder, Ber.Bunsenges. Phys.Chem. 100,1182 (1996).

[3] R.G.Lett and W.H.Flygare, J.Chem.Phys. 47,4730(1967).


[4] H.Dreizler, H.D.Rudolph, and H.Schleser, Z.Naturforsch. 25a,1643(1970).

 









 








S(CN)2







 








 








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Molecules/Nitrogen




Molecules/Sulfur

 








 













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Last Modified 27 Sept 2005