(CH3)3CO-N=O





















 








Nitrogen

Nuclear Quadrupole Coupling Constants


in tert-Butyl Nitrite


 








 








 








14N nqcc's in, and a heavy atom substitution structure of tert-butyl nitrite were determined by Heineking et al. [1].

 








Calculation of the nqcc's was made here on the substitution structure. These are compared with the experimental nqcc's in Table 1.  Structure parameters are given in Table 2.

 








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.

RMS is the root mean square difference between calculated and experimental nqcc's (percentage of average experimental nqcc).  RSD is the residual standard deviation of calibration of the B3PW91/6-311+G(df,pd) model for calculation of the nqcc's.

 








 








   






Table 1. Nitrogen nqcc's in tert-Butyl Nitrite (MHz).
   









Calc.
Expt. [1]
   






14N Xaa
0.779
0.8536(10)


Xbb - 4.380 - 4.2307


Xcc
3.601
3.3771(11)


|Xab|
3.149



 







RMS
0.161 (5.7 %)




RSD
0.030 (1.3 %)



 







Xxx
2.270
2.15(17)


Xyy
3.601
3.377(1)


Xzz - 5.871 - 5.53(17)


ETA
0.227




Øx,a
25.34
24.3(13)


Øz,bi *
17.60 
16.5(13)

 






   








* Angle between the bisector ('bi') of the ONO angle and the z-principal axis of the nqcc tensor.

 








 








Calculation of the nqcc tensor was made on the heavy atom substitution structure, with the hydrogens located by partial optimization (fixed heavy atom structure) at the MP2/6-31G(d,p) level of theory.  The CH bond lengths were corrected using r = 1.001 ropt, where ropt are the MP2/6-31G(d,p) bond lengths [3].

 









 

Table 2.  tert-Butyl Nitrite.  Heavy atom molecular structure parameters (Å and degrees).  Complete structure is given here in Z-matrix format.
   



O(1)=N 1.18183(79)

N-O(3) 1.41751(78)

O(3)C(4) 1.43752(62)

C(4)C(5) 1.52341(28)

C(4)C(6,7) 1.52902(44)

ONO 111.59(20)

NOC 111.76


OCC(5) 103.03(10)


OCC((6,7) 110.09(8)


NOCC(6,7)   61.55(10)


 








 

[1] N.Heineking, W.Jäger, and M.C.L.Gerry, J.Mol.Spectrosc. 155,403(1992).

[2] J.Demaison and G.Wlodarczak, Structural Chem. 5,57(1994).

 








 








Table of Contents




Molecules/Nitrogen




 








 













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Last Modified 13 April 2008