CH3CH2CH2CH2CH2I

















 





 








Iodine

Nuclear Quadrupole Coupling Constants


in 1-Iodopentane GGA


 








 








Calculation of the iodine nqcc tensor in the GGA 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 Signore 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 GGA (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
- 141.5
- 144.1
- 189.12(24)

Xbb
- 435.9
- 425.6
- 397.78(42)

Xcc
  577.4
  569.8
  586.90(42)

|Xab|
1184.5 *
1180.5 *
 -
 1194.329(19) *

|Xac|
  564.5
  572.2
- 572.626(30)

|Xbc|
  628.2
  633.6
- 617.745(30)

 







RMS
35.7 (9.12 %)
 32.1 (8.20 %)


RSD
15.2 (1.23 %) 15.2 (1.23 %)



 







Xxx
  877.7
  877.7
  884.81674(91)

Xyy
  906.6
  905.7
  906.15506(54)

Xzz -
 1784.3
 -
 1783.4
 -
 1790..97181(74)

ETA
0.0162
0.0157
0.01191

Øz,CI
0.58
0.56



 








 








* The product XabXacXbc is negative.

 








 

Table 2.  1-Iodopentane GGA.  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=2.14732315
 B2=1.51745623
 B3=1.52639295
 B4=1.52509415
 B5=1.52560493
 B6=1.08318197
 B7=1.08325654
 B8=1.08887397
 B9=1.0934512
 B10=1.0903365
 B11=1.09092
 B12=1.09183757
 B13=1.08996435
 B14=1.08708783
 B15=1.08824343
 B16=1.08830961
 A1=113.24878944
 A2=115.03745564
 A3=113.87544689
 A4=111.96225615
 A5=105.34759856
 A6=104.97319726
 A7=109.31071246
 A8=106.49158305
 A9=109.48313868
 A10=108.42559302
 A11=109.44013134
 A12=109.58561503
 A13=111.66318725
 A14=110.55560286
 A15=110.81640491
 D1=-59.59896145
 D2=-54.19114331
 D3=-175.05602881
 D4=-123.2260287
 D5=121.98054156
 D6=64.50580324
 D7=179.67449104
 D8=68.28470529
 D9=-175.85385737
 D10=-53.03369261
 D11=63.76765388
 D12=-179.22894462
 D13=-59.05655561
 D14=60.35837247
  B1=2.14018
 B2=1.51953964
 B3=1.52503709
 B4=1.52383774
 B5=1.52377941
 B6=1.08890248
 B7=1.0890708
 B8=1.09380292
 B9=1.09812205
 B10=1.09468866
 B11=1.09546314
 B12=1.0962988
 B13=1.09429504
 B14=1.09134373
 B15=1.09228886
 B16=1.09236777
 A1=113.10414432
 A2=115.17226166
 A3=113.93610253
 A4=112.09214377
 A5=105.75642008
 A6=105.39419136
 A7=109.23665596
 A8=106.33147444
 A9=109.54497456
 A10=108.2544156
 A11=109.23056375
 A12=109.55987151
 A13=111.47720533
 A14=110.42500325
 A15=110.71644006
 D1=-59.95991599
 D2=-53.93483709
 D3=-173.07643111
 D4=-123.03185578
 D5=121.68525705
 D6=64.04690965
 D7=179.35529444
 D8=68.66350362
 D9=-175.36185543
 D10=-51.18601013
 D11=65.74131912
 D12=-178.60266069
 D13=-58.46461629
 D14=61.01752278





 













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 3706.
 3758.
   3796.2217(20)

B   805.
   799.
     772.08599(29)

C   714.
   711.
     690.40061(21)



 








 















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








 Calc
 Expt [1]
 






D_J
0.371
0.5031(20)

D_JK
 -
 5.89
 -
 6.398(24)

D_K
31.5
28.29(43)

d_1
 -
 0.0739



d_2
 -
 0.00219




 








 








[1]  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 GAA 1-Iodobutane AA

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

 








 








Table of Contents




Molecules/Iodine




 








 













1_Iodopentane_GGA.html






Last Modified 31 Aug 2019