m-Cl-C6H4-C(=O)H















 








 









Chlorine


Nuclear Quadrupole Coupling Constants

in meta-Chlorobenzaldehyde

 








 








 

 





Calculation of chlorine nuclear quadrupole coupling constant tensors in meta-chlorobenzaldehyde was made here on ropt molecular structures given by B3P86/6-31G(3d,3p) optimization (assuming Cs symmetry) of each of the two  conformers shown below:

 








cis

trans


At the


B1LYP/TZV(3df,2p)

level of theory

Etrans < Ecis

by 0.075 kJ/mol





 








 








Calculated and experimental [1] nqcc's are compared in Tables 1 and 2, rotational constants and electric dipole moments are given in Table 3.  Structure parameters are given here in Z-matrix format.

 








In Tables 1 and 2, 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.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

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

 








 








   






Table 1.  Chlorine nqcc's in cis meta-Chlorobenzaldehyde (MHz).  Calculation was made on B3P86/6-31G(3d,3p) ropt structure.
   









Calc
Expt [1]
   






35Cl Xaa -
 37.79
 -
 37.38(5)


Xbb
  4.85
  4.2(1)


Xcc
32.94
33.18 *


|Xab|
52.04



 







RMS
0.47 (1.9 %)




RSD
 0.49 (1.1 %)


 







Xxx
39.77




Xyy
32.94




Xzz -
 72.71




ETA
 -
 0.0939




Øz,a
33.86




Øa,CCl
33.92




Øz,CCl
  0.06



 






37Cl Xaa -
 30.96
 -
 30.58(5)


Xaa
  5.00
  4.45(9)


Xaa
25.96
26.13 *


|Xab|
40.51



 







RMS
0.40 (2.0 %)




RSD
0.44 (1.1 %)



 







 








* Calculated from zero-trace condition.

 








 








   






Table 2.  Chlorine nqcc's in trans meta-Chlorobenzaldehyde (MHz).  Calculation was made on B3P86/6-31G(3d,3p) ropt structure.
   









Calc
Expt [1]
   






35Cl Xaa -
 53.03
 -
 52.1(5)


Xbb
19.80
18.5(5)


Xcc
33.23
33.6 *


|Xab|
42.61



 







RMS
0.95 (2.7 %)




RSD
 0.49 (1.1 %)


 







Xxx
39.44




Xyy
33.23




Xzz -
 72.67




ETA
 -
 0.0854




Øz,a
24.74




Øa,CCl
24.73




Øz,CCl
  0.01



 






37Cl Xaa -
 42.32
 -
 42.(1)


Xaa
16.13
14.9(8)


Xaa
26.19
27.2 *


|Xab|
33.13



 







RMS
0.90 (3.2 %)




RSD
0.44 (1.1 %)



 







 








* Calculated from zero-trace condition.

 








 







 




Table 3.  meta-Chlorobenzaldehyde, 35Cl species.  Rotational Constants (MHz) and Electric Dipole Moments * (D).

 


cis
   ropt   Expt. [1]





A
 2356.4
 2345.808(2)

B
   962.8
   959.439(1)

C
   683.5
   680.9698(8)

|µa|
   0.51

|µb|   3.66

 


trans






A
 3194.0
 3172.65(9)

B
   815.4
   813.009(1)

C
   649.6
   647.232(1)

|µa|   1.91

|µb|   0.86





* B1LYP/TZV(3df,2p) calculation on B3P86/6-31G(3d,3p) structures.



 








 








[1] S.Arnold, J.Garrett, and G.Brown, Abstract RK15, 68th International Symposium on Molecular Spectroscopy, June 17-21, 2013.

 








 








Chlorobenzene
 o-Chlorobenzaldehyde
 m-Chlorobenzonitrile

1,3-Dichlorobenzene
 1,3-Chlorofluorobenzene m-Chlorophenol

 








 








Table of Contents




Molecules/Chlorine




 








 













3Chlorobenzaldehyde.html






Last Modified 8 Aug 2013