CH3CH2CH2CH2CH2I

















 





 








Iodine

Nuclear Quadrupole Coupling Constants


in 1-Iodopentane GAA


 








 








Calculation of the iodine nqcc tensor in the GAA conformer of 1-iodopentane was made on molecular structures obtained by MP2/6-311G(2d,2p) and MP2/6-311G(df,pd) optimization.  These calculated nqcc's are compared with the experimental values of Stephens et al. [1] in Table 1.  Structure parameters are given in Table 2, rotational constants in Table 3, quartic centrifugal distortion constants in Table 4.

 








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.  ETA = (Xxx - Xyy)/Xzz.  Ø (degrees) is the angle between its subscripted parameters.

RMS is the root mean square difference between calculated and experimental diagonal nqcc's (percent of the average of the magnitudes of the experimental nqcc's).  RSD is the residual standard deviation of calibration of the B1LYP/6-311G(df,p) model for calculation of the efg's/nqcc's.

 








 








   







Table 1.  127I nqcc's in 1-Iodopentane GAA (MHz).  Calculation was made on the following structures:  ropt (1) = MP2/6-311G(2d,2p) optimization, and ropt (2) = MP2/6-311G(df,pd) optimization.

 









Calc. (1)
Calc. (2)
   Expt [1]
   







Xaa
  - 96.3
  - 89.7
  - 99.028(13)

Xbb
- 686.3
- 692.1
- 689.73(10)

Xcc
  782.7
  781.8
  788.76(10)

|Xab|
1265.2 *
1263.9 *
1268.799(16) *

|Xac|
  309.3
  309.0
  310.843(41)

|Xbc|
  416.4
  418.0
  418.183(37)

 







RMS
  4.3 (0.82 %)
   6.8 (1.30 %)


RSD
15.2 (1.23 %) 15.2 (1.23 %)



 







Xxx
  878.1
  877.9
  883.02(8)

Xyy
  916.7
  917.0
  918.78(6)

Xzz -
 1794.8
 -
 1794.9
 -
 1801.80(6)

ETA
0.0215
0.0218
0.01985(5)

Øz,CI
0.73
0.76



 








 








* The product XabXacXbc is negative.

 








 

Table 2.  1-Iodopentane GAA.  ropt (1) = MP2/6-311G(2d,2p) optimization, and ropt (2) = MP2/6-311G(df,pd) structure parameters (Å and degrees). 
 

 

 I
 C,1,B1
 C,2,B2,1,A1
 C,3,B3,2,A2,1,D1,0
 C,4,B4,3,A3,2,D2,0
 C,5,B5,4,A4,3,D3,0
 H,2,B6,1,A5,3,D4,0
 H,2,B7,1,A6,3,D5,0
 H,3,B8,2,A7,1,D6,0
 H,3,B9,2,A8,1,D7,0
 H,4,B10,3,A9,2,D8,0
 H,4,B11,3,A10,2,D9,0
 H,5,B12,4,A11,3,D10,0
 H,5,B13,4,A12,3,D11,0
 H,6,B14,5,A13,4,D12,0
 H,6,B15,5,A14,4,D13,0
 H,6,B16,5,A15,4,D14,0




ropt (1) ropt (2)




 B1=2.14733563
 B2=1.51645302
 B3=1.52271416
 B4=1.52514572
 B5=1.52545648
 B6=1.0847406
 B7=1.08327808
 B8=1.08975218
 B9=1.09332745
 B10=1.09267084
 B11=1.09024083
 B12=1.09071179
 B13=1.09086673
 B14=1.08711528
 B15=1.08831407
 B16=1.08813519
 A1=113.14424199
 A2=114.27831769
 A3=112.65641349
 A4=112.30689646
 A5=105.47660665
 A6=104.89189726
 A7=109.74591573
 A8=106.950412
 A9=109.21497636
 A10=109.54675503
 A11=109.04425421
 A12=109.3674165
 A13=111.64636779
 A14=110.77089978
 A15=110.71336166
 D1=-66.10571591
 D2=-176.58963676
 D3=-179.60819334
 D4=-122.39101408
 D5=122.46857403
 D6=57.92831874
 D7=173.41508828
 D8=-54.82574181
 D9=61.52279525
 D10=-57.7716507
 D11=58.28685925
 D12=179.88572257
 D13=-59.82591973
 D14=59.57964874
  B1=2.14061169
 B2=1.518786
 B3=1.52174684
 B4=1.52389772
 B5=1.52352186
 B6=1.09037288
 B7=1.08900401
 B8=1.09439069
 B9=1.09772635
 B10=1.09694024
 B11=1.09434384
 B12=1.09513277
 B13=1.09527766
 B14=1.09138624
 B15=1.09237124
 B16=1.0922078
 A1=113.13278272
 A2=114.41918906
 A3=112.76027342
 A4=112.42877511
 A5=105.8665175
 A6=105.27888548
 A7=109.63875492
 A8=106.75132387
 A9=109.10010499
 A10=109.44582332
 A11=108.88930135
 A12=109.19802612
 A13=111.46615283
 A14=110.6384349
 A15=110.59558071
 D1=-65.87717596
 D2=-176.0860766
 D3=-179.26989123
 D4=-122.15968791
 D5=122.21706554
 D6=57.9877977
 D7=173.69922996
 D8=-54.42859192
 D9=62.12839867
 D10=-57.46413627
 D11=58.71071793
 D12=179.91294752
 D13=-59.84312387
 D14=59.63894389





 













Table 3.  1-Iodopentane GAA.  Rotational Constants (MHz).  ropt (1) = MP2/6-311G(2d,2p), and ropt (2) = MP2/6-311G(df,pd) optimization.
 





ropt(1) ropt(2)     Expt [1]
 




A 4941.
 4955.
   4898.1135(11)

B   623.
   624.
     618.94217(16)

C   573.
   573.
     568.66058(13)



 








 















Table 4.  1-Iodopentane GAA.  Quartic Centrifugal Distortion Constants (kHz).  Calc = B3LYP/6-311G(d,p).
 








 Calc
 Expt [1]
 






D_J
0.101
0.10234(77)

D_JK
 -
 2.60
 -
 2.517(11)

D_K
28.09
25.64(23)

d_1
 -
 0.0174
 -
 0.01810(58)

d_2
 -
 0.0005




 








 








[1] S.L.Stephens, J.A.Signore, D.A.Obenchain, R.K.Bohn, S.E.Novick, and S.A.Cooke, Abstract WJ06, 73rd International Symposium on Molecular Spectroscopy, Champaign-Urbana, Ill 2018.

 








J.A.Signore, S.L.Stephens, L.Cheng, W.C.Bailey, S.A.Cooke, and S.E.Novick, Abstract TJ04, 74th International Symposium on Molecular Spectroscopy, Champaign-Urbana, Ill 2019.

 








1-Iodopentane AAA
 1-Iodopentane GGA



CH3I CH3CH2I trans-1-Iodopropane
 gauche-1-Iodopropane

1-Iodobutane AA






 








 








Table of Contents




Molecules/Iodine




 








 













1_Iodopentane_GAA.html






Last Modified 28 June 2018