g-CH2OH-CH2CN




 





 





 





 





 









Nitrogen


Nuclear Quadrupole Coupling Constants

in gauche 3-Hydroxypropanenitrile


 








 








 








The microwave spectra of CH2OH-CH2CN and CH2OD-CH2CN have been investigated by Marstokk and Møllendal [1].  Three conformations were assigned, the most stable being the gauche conformation shown above.  Calculation was made here of approximate equilibrium structures of this conformer (see below).  And on these structures, calculation was made of the nitrogen nqcc's.

 








The calculated nqcc's are given in Tables 1 and 2 for CH2OH-CH2CN and CH2OD-CH2CN respectively.  Structure parameters are given in Table 3, rotational constants in Table 4.

 








In Tables 1 and 2, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  Øz,CN (degrees) is the angle between the z-principal axis and the CN bond direction.  ETA = (Xxx - Xyy)/Xzz.

RSD is the calibration residual standard deviation for the B3PW91/6-311+G(df.pd) model for calculation of the nitrogen nqcc's, which may be taken as an estimate of the uncertainty in the calculated nqcc's.

 








  








   








Table 1.  Nitrogen nqcc's in g-CH2OH-CH2CN (MHz).  Calculation was made on approximate equilibrium structures ~re(1) and ~re(2).

 









Calc ~re(1)
Calc ~re(2)
Expt.
   








Xaa - 1.542 - 1.517



Xbb - 0.341 - 0.370



Xcc
1.884
1.887



|Xab|
3.128 *
3.126 *



|Xac|
0.763
0.759



|Xbc|
0.539
0.550



 







RSD
0.030 (1.3 %)
0.030 (1.3 %)



 







Xxx
2.005
2.012



Xyy
2.263
2.253



Xzz - 4.268 - 4.265



ETA
0.060
0.056



Øz,CN
0.87
0.90



 







   








* The product XabXacXbc is negative.

 








 








   








Table 2.  Nitrogen nqcc's in g-CH2OD-CH2CN (MHz).  Calculation was made on approximate equilibrium structures ~re(1) and ~re(2).

 









Calc ~re(1)
Calc ~re(2)
Expt.
   








Xaa - 1.463 - 1.436



Xbb - 0.421 - 0.452



Xcc
1.884
1.888



|Xab|
3.142 *
3.141 *



|Xac|
0.755
0.751



|Xbc|
0.548
0.559



 







RSD
0.030 (1.3 %)
0.030 (1.3 %)



 








 








* The product XabXacXbc is negative.

 








 








Molecular Structure
















~re(1):  After optimization at the MP2/6-311+G(d,p) and MP2/6-31G(d,p) levels of theory; C-C, CN, and CH bond lengths were corrected as described here.  Interatomic angles and C-O-H geometry parameters are those given by MP2/6-311+G(d,p) optimization. 

~re(2):  After optimization at the MP2/6-311+G(3df,3pd) level of theory; C-C and CN bond lengths were corrected as described here.  C-H bond lengths, interatomic angles, and C-O-H geometry parameters are those given by optimization.

 








 


Table 3.  g-CH2OH-CH2CN.  Selected structure parameters.  Complete structures are given here in Z-matrix (G03 input) format.
 


Point Group C1
~ re(1) ~ re(2)





C(1)C(2) 1.5275 1.5286
C(2)O(7) 1.4140 1.4093
O(7)H(8) 0.9630 0.9618
C(1)C(2)O(7) 112.01 111.98
C(2)O(7)H(8) 107.73 108.43
C(1)C(9) 1.4609 1.4599
C(9)N(10) 1.1563 1.1562
C(2)C(1)C(9) 110.28 109.86
Click on image to enlarge.
C(1)C(9)N(10) 176.11 175.93


 








 













Table 3.  Rotational constants (MHz).
 





g-CH2OH-CH2CN
 



 
~ re(1) ~ re(2)    Expt. [1]
 




A 10 706.8 10 689.7 10 726.4535(36)

B   3 477.8   3 497.4   3 432.3084(11)

C   2 845.0   2 858.0   2 815.6078(15)
   




g-CH2OD-CH2CN
 




A 10 243.5 10 221.6 10 237.154(18)

B   3 460.9   3 480.0   3 419.491(14)

C   2 800.2   2 812.1   2 771.972(14)


 








 








[1] K.-M.Marstokk and H.Møllendal, Acta Chemica Scand. A 39,15(1985).

 








R.Braakman and G.A.Blake, J.Mol.Spectrosc. 262,100(2010)  mm-wave












 








g-CH2SH-CH2CN gauche-1-Cyanopropane CH3CH2CN


 








 








Table of Contents




Molecules/Nitrogen




 








 













HOCH2CH2CN.html






Last Modified 4 Dec 2008