HCCCH2SCN































 








Nitrogen

Nuclear Quadrupole Coupling Constants


in Propargylthiocyanate


 








 








 








Calculation of the nitrogen nqcc tensor in the antiperiplanar (ap) conformer of propargylthiocyanate was made here on a molecular structure given by MP2/6-311+G(3df,3pd) optimization with ~re C-C, CC triple, and CN triple bond lengths.  These calculated nqcc's are given in Table 1, structure parameters in Table 2, and  rotational constants in Table 3.

 








In Table 1, 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.  The nqcc y-axis is chosen coincident with the inertia c-axis, these are perpendicular to the Cs plane of the molecule.  Ø (degrees) is the angle between its subscripted parameters. ETA = (Xxx - Xyy)/Xzz.

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. Nitrogen nqcc's in ap Propargylthiocyanate (MHz).
   









Calc.
Expt.
   






14N Xaa - 2.643




Xbb
1.658




Xcc
0.985




|Xab|
2.845



 







RSD
0.030 (1.3 %)



 







Xxx
3.074




Xyy
0.985




Xzz - 4.058




ETA - 0.515




Øz,a
26.46




Øa,CN
26.13




Øz,CN
  0.33



 






   








 









 


Table 2.  ap Propargylthiocyanate and ap Propargylselenocyanate.  MP2 molecular structure parameters (Å and degrees).  
   





X = Se
 X = S





HC(5) 1.06221.0621

C(5)C(4) 1.20451.2039

C(4)C(1) 1.44941.4519

C(1)H(2,3) 1.08711.0880

C(1)X 1.97331.8322

XC(8) 1.83461.6851

C(8)N 1.16061.1607

C(1)C(4)C(5) 177.95178.48

C(1)XC(8)   94.82  97.36

XC(8)N 179.90179.19

HC(1)H 110.16109.67

H(2,3)C(1)C(4) 111.91111.39


 








 


Table 3.   ap Propargylthiocyanate.  Rotational Constants (MHz).






  Calc   Expt. [1]





A 14191.9 14134.0(39)

B   1390.4
   1382.5018(79)

C   1276.6
   1269.3008(79)


 








 








[1] H.Mollendal, A.Konovalov, and J.-C.Guillemin, J.Phys.Chem. A 114,2300(2010).

 








 








Table of Contents




Molecules/Nitrogen




 








 













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Last Modified 28 Nov 2013