IHC=C=CH2
































 






Iodine


Nuclear Quadrupole Coupling Constants

in Iodoallene

 








 








Calculation of the 127I nqcc tensor in iodoallene was made here on molecular structures given by MP2/6-311+G(d,p), MP2/6-311+G(2d,p), and MP2/6-311G(3df,3pd) optimizations; and on these same structures but with empirically corrected C=C and CH bond lengths.  These nqcc's are compared with the experimental values [1] in Tables 1 - 3.  Structure parameters are given in Table 4, rotational constants in Table 5.

 








In Tables 1 - 3, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  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 (percent of the average of the magnitudes of the experimental nqcc's).  RSD is the calibration residual standard deviation of the B1LYP/6-311G(df,p) model for calculation of the nqcc's, which may be taken as an estimate of the uncertainties in the calculated nqcc's (uncertainties in the optimized molecular structures notwithstanding).

 








 








   







Table 1. 127I nqcc's in Iodoallene (MHz).  

 







Calc (1) was made on the MP2/6-311+G(d,p) optimized molecular structure.

Calc (2) was made on this same structure but with empirically corrected C=C, and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt. [1]
   







Xaa - 1429.7 - 1431.1 - 1399.25(83)

Xbb
  470.8
  472.4
  428.34

Xcc
  958.9
  958.7
  970.91(64)

|Xab|
1200.4
1196.7
1220.52(27)

 







RMS
31.0 (3.32 %)
32.2 (3.45 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
1051.5
1049.7
1039.24(57)

Xyy
  958.9
  958.7
  970.91(64)

Xzz - 2010.4 - 2008.4 -
 2010.15(64)

ETA - 0.0460 - 0.0453 -
 0.03399(44)

Øz,a
25.82
25.75
26.97

Øa,CI
26.39





Øz,CI
  0.58





 
 






 








 








   







Table 2. 127I nqcc's in Iodoallene (MHz).  

 







Calc (1) was made on the MP2/6-311+G(2d,p) optimized molecular structure.

Calc (2) was made on this same structure but with empirically corrected C=C, and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt. [1]
   







Xaa - 1422.2 - 1422.7 - 1399.25(83)

Xbb
  472.5
  473.0
  428.34

Xcc
  949.7
  949.7
  970.91(64)

|Xab|
1192.0
1190.7
1220.52(27)

 







RMS
31.2 (3.35 %)
31.6 (3.39 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
1047.8
1047.1
1039.24(57)

Xyy
  949.7
  949.7
  970.91(64)

Xzz - 1997.5 - 1996.8 -
 2010.15(64)

ETA - 0.0491 - 0.0488 -
 0.03399(44)

Øz,a
25.76
25.74
26.97

Øa,CI
26.31





Øz,CI
  0.55





 
 





   








 








   







Table 3. 127I nqcc's in Iodoallene (MHz).  

 







Calc (1) was made on the MP2/6-311G(3df,3pd) optimized molecular structure.

Calc (2) was made on this same structure but with empirically corrected C=C, and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt. [1]
   







Xaa - 1397.9 - 1398.0 - 1399.25(83)

Xbb
  454.1
  454.1
  428.34

Xcc
  943.8
  943.9
  970.91(64)

|Xab|
1198.5
1198.5
1220.52(27)

 







RMS
21.6 (2.32 %)
21.6 (2.31 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
1042.6
1042.6
1039.24(57)

Xyy
  943.8
  943.9
  970.91(64)

Xzz - 1986.4 - 1986.5 -
 2010.15(64)

ETA - 0.0450 - 0.0497 -
 0.03399(44)

Øz,a
26.15
26.15
26.97

Øa,CI
26.66





Øz,CI
  0.51





 
 






 








 












Table 4.  Iodoallene.  Heavy atom structure parameters (Å and degrees).  
 



r (1) = MP2/6-311+G(d,p) opt

r (2) = r (1) with corrected C=C, and CH bond lengths.
 


Point Group CS
  r (1)   r (2)





IC(2) 2.1102 2.1102
C(2)-C(4) 1.3078 1.3009
C(4)=C(5) 1.3154 1.3079
IC(2)-C(4) 122.16 122.16
C(2)=C(4)=C(5) 179.20 179.20
 

r (1) = MP2/6-311+G(2d,p) opt
r (2) = r (1) with corrected C=C, and CH bond lengths.




  r (1)   r (2)



IC(2) 2.0916 2.0916
C(2)-C(4) 1.3032 1.3009
C(4)=C(5) 1.3108 1.3079
IC(2)-C(4) 122.81 122.81
C(2)=C(4)=C(5) 179.86 179.86
 


r (1) = MP2/6-311G(3df,3pd) opt

r (2) = r (1) with corrected C=C, and CH bond lengths.






  r (1)   r (2)





IC(2) 2.0862 2.0862

C(2)-C(4) 1.3022 1.3009

C(4)=C(5) 1.3078 1.3079

IC(2)-C(4) 122.26 122.26

C(2)=C(4)=C(5) 179.71 179.71


 








 













Table 5.  Iodoallene.  Rotational constants (MHz).  
 




r (1) = MP2/6-311+G(d,p) opt

r (2) = r (1) with corrected C=C, and CH bond lengths.







  r (1)   r (2)    Expt. [1]






A 25702.5 25848.4 25079.235(34)

B   1585.6
   1593.3
   1620.5203(20)

C   1509.1
   1516.5
   1537.0119(16)
 
 


r (1) = MP2/6-311+G(2d,p) opt

r (2) = r (1) with corrected C=C, and CH bond lengths.






A 26118.0 26166.4 25079.235(34)

B   1599.9
   1602.8
   1620.5203(20)

C   1523.5   1526.2
   1537.0119(16)
 
 


r (1) = MP2/6-311G(3df,3pd) opt

r (2) = r (1) with corrected C=C, and CH bond lengths.






A 25704.2 25695.5 25079.235(34)

B   1617.4
   1618.2
   1620.5203(20)

C   1537.8
   1538.5
   1537.0119(16)


 








 








[1[ T.Ogata and Y.Niide, J.Chem.Soc. Faraday Trans. 92,4889(1996).

 








 








Chloroallene
 Bromoallene
 Cyanoallene

t-Iodopropane
 2-Iodopropene



 








 








Table of Contents




Molecules/Iodine




 








 













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Last Modified 17 April 2013