CH3CH2CH2NC























 





 








Nitrogen

Nuclear Quadrupole Coupling Constants


in trans-Propyl Isocyanide


 








 








 








Calculation of the nitrogen nqcc's in trans-propyl isocyanide was made on molecular structures obtained by B3P86/6-31G(3d,3p) and mPW1PW91/6-31G(3d,3p) optimization.  These are compared in Table 1 with the experimental nqcc's of Krüger and Dreizler [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.  The nqcc y-axis is chosen coincident with the inertia c-axis, these are perpendicular to the molecular plane.  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 B3PW91/6-311+G(df,pd) model for calculation of the nitrogen efg's/nqcc's.

 








 








   







Table 1.  14N nqcc's in trans-CH3CH2CH2NC (MHz).  Calculation was made on (1) B3P86/6-31G(3d,3p) and (2) mPW1PW91/6-31G(3d,3p) optimized structures.
   









Calc (1)
Calc (2)
Expt. [1]
   







Xaa
0.311
0.305
0.2681(71)

Xbb - 0.135 - 0.132 - 0.1080(23)

Xcc -
 0.176 -
 0.173 - 0.1600(23)

|Xab|
0.185
0.182



 







RMS
0.031 (17 %)
0.027 (15 %)



RSD
0.030 (1.3 %)
0.030 (1.3 %)



 







Xxx -
 0.201 -
 0.198



Xyy -
 0.176 -
 0.173



Xzz
0.378
0.371



ETA - 0.0667 - 0.0666



Øz,a
19.80
19.88



Øa,NC
21.87
21.91



Øz,NC
  2.07
  2.03



 








 








 

Table 2.  Molecular structure parameters: B3P86/6-31G(3d,3p) and mPW1PW91/6-31G(3d,3p) opt structures (Å and degrees).
 


 C
 C,1,B1
 C,2,B2,1,A1
 H,1,B3,2,A2,3,D1,0
 H,1,B4,2,A3,3,D2,0
 H,2,B5,1,A4,3,D3,0
 H,2,B6,1,A5,3,D4,0
 H,3,B7,2,A6,1,D5,0
 H,3,B8,2,A7,1,D6,0
 H,3,B9,2,A8,1,D7,0
 N,1,B10,2,A9,3,D8,0
 C,11,B11,1,A10,2,D9,0




       B3P86
   mPW1PW91




 B1=1.52583987
 B2=1.52160464
 B3=1.09505949
 B4=1.09505949
 B5=1.09407782
 B6=1.09407782
 B7=1.09186873
 B8=1.09410273
 B9=1.09410273
 B10=1.41924139
 B11=1.17094366
 A1=111.44706368
 A2=110.51054188
 A3=110.51054188
 A4=108.7534553
 A5=108.7534553
 A6=110.9126031
 A7=111.44226211
 A8=111.44226211
 A9=112.05362125
 A10=178.19636302
 D1=-59.26786262
 D2=59.26786262
 D3=122.10805679
 D4=-122.10805679
 D5=180.
 D6=-60.15959385
 D7=60.15959385
 D8=180.
 D9=0.
  B1=1.52580432
 B2=1.52153395
 B3=1.0941235
 B4=1.0941235
 B5=1.09334493
 B6=1.09334493
 B7=1.09117651
 B8=1.09334516
 B9=1.09334516
 B10=1.41882012
 B11=1.16940857
 A1=111.51616687
 A2=110.53308632
 A3=110.53308632
 A4=108.74226572
 A5=108.74226572
 A6=110.87387568
 A7=111.45631272
 A8=111.45631272
 A9=112.006657
 A10=178.2126864
 D1=-59.30084843
 D2=59.30084843
 D3=122.11614645
 D4=-122.11614645
 D5=180.
 D6=-60.18012561
 D7=60.18012561
 D8=180.
 D9=0.





 













Table 3.  Rotational Constants; B3P86/6-31G(3d,3p), mPW1PW91/6-31G(3d,3p), and experimental (MHz).







B3P86
 mPW1PW91      Expt [1]






A
 23987.
     24000.
 23693.7163(26)

B
   2410.
       2412.
   2407.65324(28)

C
   2283.
       2284.
   2278.84572(27)



 








 








[1] M.Krüger and H.Dreizler, Z.Naturforsch. 47a,1067(1992).

 








 








CH3CH2NC CH3NC CF3NC HCCNC

(CH3)3CNC C6H5NC CNCN HNC

CH2=CHNC gauche CH3CH2CH2NC Isopropyl-NC

 








 








Table of Contents




Molecules/Nitrogen




 








 













tCH3CH2CH2NC.html






Last Modified 13 Feb 2016