C(H)Cl=C(H)CCH




























 







Chlorine


Nuclear Quadrupole Coupling Constants


in cis-1-Chlorobuten-3-yne


 








 








 








Calculation of the chlorine nqcc's in c-1-chlorobuten-3-yne was made on an approximate equilibrium structure derived here by MP2/aug-cc-pVTZ optimization with empirically corrected bond lengths.  These nqcc's are compared with the experimental values [1] in Table 1.  Structure parameters in Z-matrix format 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.  The nqcc y-axis is chosen coincident with the inertia c-axis, these are perpendicular to the molecular symmetry plane.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

RMS is root mean square difference between calculated and experimental nqcc's.  RSD is the calibration residual standard deviation for the B1LYP/TZV(3df,2p) model for calculation of the chlorine efg's/nqcc's.

 








 








   






Table 1. Chlorine nqcc's in t-1-Chlorobuten-3-yne (MHz).
   









Calc.
Expt. [1]
   






35Cl Xaa
18.40
16.3(4)


Xbb -
 47.26
 -
 46.8(2)


Xcc
28.86
30.5 *


|Xab|
45.78











  RMS
1.56 (5.0 %)




RSD
0.49 (1.1 %)



 







Xxx
41.90




Xyy
28.86




Xzz - 70.76




ETA - 0.184




Øz,a
62.82




Øa,CCl
63.09




Øz,CCl
  0.27



   





37Cl Xaa
13.73
11.8(8)


Xbb -
 36.47
 -
 36.2(4)


Xcc
22.74
24.4 *


|Xab|
36.62











  RMS
1.48 (6.1 %)




RSD
0.44 (1.1 %)



 







 








* Calculated here from zero trace condition.

 

Table 2.  c-1-Chlorobuten-3-yne   MP2/aug-cc-pVTZ Structure parameters (Å and degrees).   Approximate equilibrium bond lengths are given in parentheses.
 


 C
 C,1,B1
 Cl,1,B2,2,A1
 H,1,B3,2,A2,3,D1,0
 H,2,B4,1,A3,4,D2,0
 C,2,B5,1,A4,4,D3,0
 C,6,B6,1,A5,2,D4,0
 H,7,B7,1,A6,2,D5,0


 B1=1.34210866    (1.3382)
 B2=1.71559225    (1.7124)
 B3=1.07923551
 B4=1.08302349
 B5=1.41599489    (1.4190)
 B6=1.2185639      (1.2078)
 B7=1.06222861
 A1=123.23882961
 A2=122.2191859
 A3=117.07036246
 A4=124.44665883
 A5=154.0279506
 A6=162.05739626
 D1=180.
 D2=0.
 D3=180.
 D4=180.
 D5=180.




 








 













Table 3.  c-1-Chlorobuten-3-yne, 35Cl species.  Rotational Constants (MHz).   Calc is on the approximate re molecular structure.
 






Calc.
  Expt. [1]







A
 8926
 8942.40(1)


B
 2592
 2572.271(4)


C
 2009
 1994.994(3)



 







 







[1] F.Karlsson, M.Granberg, and R.Vestin, Acta Chem. Scand. A 29,855(1975).

 








 








CH2=C=C=CHCl
 2-Chlorobuten-3-yne 4-Chlorobuten-3-yne t-1-Chlorobuten-3-yne

 








 








Table of Contents




Molecules/Chlorine




 








 













c1Clbuten3yne.html






Last Modified 27 April 2014