CH3CH2-CCCN



 


























 








 









Nitrogen


Nuclear Quadrupole Coupling Constants

in Ethylcyanoacetylene

 








 








 








Calculation was made here of the N nqcc tensor in CH3CH2-CCCN on approximate equilibrium molecular structures given by (1) MP2/aug-cc-pVTZ optimization with empirically corrected bond lengths, and (2) MP2/6-311+G(3df,3pd) optimization with empirically corrected bond lengths.   Calculated nqcc tensors are given in Table 1.  Structure parameters are given in Table 2, rotational constants in Table 3.

 








In Table 1, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

RSD is the calibration residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of the efg's/nqcc's.

 








 







 
   







Table 1.  14N nqcc's in CH3CH2-CCCN (MHz).  Calculation was made on (1) MP2/aug-cc-pVTZ and (2) MP2/6-311+G(3df,3pd) approximate equilibrium molecular structures.
   









Calc (1)
Calc (2)
Expt
   







Xaa -
 4.024
 -
 4.025



Xbb
1.938
1.938



Xcc
2.086
2.087



|Xab|
1.044
1.044



 







RSD
0.030 (1.3 %)
0.030 (1.3 %)



 







Xxx
2.114
2.115



Xyy
2.087
2.087



Xzz -
 4.201
 -
 4.202



ETA -
 0.0068
 -
 0.0066



Øz,a
9.65
9.65



Øa,CN
9.66
9.67



Øz,CN
0.01
0.02



 








 








 








 

Table 2.  Ethylcyanoacetylene.  Optimized and approximate equilibrium structure parameters (Å and degrees).   (1) MP2/aug-cc-pVTZ and (2) MP2/6-311+G(3df,3pd).  Empirically corrected reapprox bond lengths are given in parentheses.
 



 C
 C,1,B1
 H,1,B2,2,A1
 H,1,B3,2,A2,3,D1,0
 H,1,B4,2,A3,4,D2,0
 H,2,B5,1,A4,5,D3,0
 H,2,B6,1,A5,5,D4,0
 C,2,B7,1,A6,5,D5,0
 C,8,B8,2,A7,1,D6,0
 C,9,B9,8,A8,2,D7,0
 N,10,B10,9,A9,8,D8,0
 
MP2/aug-cc-pVTZ
 MP2/6-311+G(3df,3pd)
 
 B1=1.5313494        (1.5288)
 B2=1.0880976
 B3=1.08850224
 B4=1.0880976
 B5=1.09147865
 B6=1.09147865
 B7=1.45491128       (1.4558)
 B8=1.22194591       (1.2097)
 B9=1.36923005       (1.3739)
 B10=1.1783106       (1.1613)
 A1=110.58253682
 A2=110.00255232
 A3=110.58253682
 A4=110.30121416
 A5=110.30121416
 A6=111.77619622
 A7=178.02129387
 A8=179.514381
 A9=179.93765051
 D1=119.99015645
 D2=119.99015645
 D3=61.04631563
 D4=178.93399728
 D5=-60.00984355
 D6=0.
 D7=180.
 D8=180.
  B1=1.53104543        (1.5285)
 B2=1.0875278
 B3=1.0879558
 B4=1.0875278
 B5=1.09100947
 B6=1.09100947
 B7=1.45480322        (1.4559)
 B8=1.22075779        (1.2095)
 B9=1.36833372        (1.3736)
 B10=1.1770092        (1.1613)
 A1=110.58772775
 A2=109.99881764
 A3=110.58772775
 A4=110.25250429
 A5=110.25250429
 A6=111.77295098
 A7=178.00893753
 A8=179.49989718
 A9=179.92346463
 D1=119.97853447
 D2=119.97853447
 D3=61.05535503
 D4=178.9017139
 D5=-60.02146553
 D6=0.
 D7=180.
 D8=180.



 













Table 3.  Ethylcyanoacetylene.  Rotational constants (MHz).  Approximate equilibrium (1) MP2/aug-cc-pVTZ and (2) MP2/6-311+G(3df,3pd) structures.
 





reapprox(1) reapprox(2)    Expt [1]






A 21525.6
 21536.0
 21750(21)

B   1352.2
   1352.5
   1344.8187(30)

C   1292.6
   1292.9
   1285.4798(29)


 








 








[1] S.Carles, H.Møllendal, and J.-C.Guillemin, A&A 558,A6(2013).

 








 








Calculation of Nuclear Quadrupole Coupling Constants on Approximate Equilibrium Structures: Acetylenes

 








 








Table of Contents




Molecules/Nitrogen




 








 













CH3CH2CCCN.html






Last Modified 13 Oct 2013