BrCH2CH2CH2CH3
































 









Bromine


Nuclear Quadrupole Coupling Constants

in 1-Bromobutane, GG

 








 








Calculation of the bromine nqcc tensors in 1-bromobutane, GG was made here on a molecular structure given by MP/6-311+G(3df,3pd) optimization, and on this same structure but with empirically corrected approximate equilibrium C-C and CBr bond lengths.  These calculated nqcc's are compared with the experimental values of Kim et al. [1] in Tables 1 and 2.  Structure parameters are given in Table 3, rotational constants in Table 4.  (Links to AA and GA conformers are given below.)

 








In Tables 1 and 2, subscripts a,b,c refer to the principal axes of the inertia tensor; 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 (percentage of the average of the magnitudes of the experimental nqcc's).  RSD is the calibration residual standard deviation of the B1LYP/TZV(3df,3p) model for calculation of the efg's/nqcc's.  

 








 








   







Table 1.  79Br nqcc's in 1-Bromobutane, GG (MHz).  

 







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

Calc (2) was made on this same structure but with empirically corrected C-C and CBr bond lengths.

 









Calc (1)
Calc (2)
Expt. [1]
   







Xaa
153.23
154.85
157.83(11)

Xbb
  - 4.21
  - 4.79
  - 7.93(28) *

Xcc -
 149.02
 -
 150.06
 -
 149.90(28) *

|Xab| **
337.41
337.97
336.11(28)

|Xac|
223.91
223.75
221.62(31)

|Xbc|
176.49
175.83
172.68(76)

 







RMS
3.45 (3.28 %)
2.50 (2.37 %)



RSD
1.58 (0.39 %)
1.58 (0.39 %)



 







Xxx -
 266.99
 -
 267.30
 -
 264.88(54)

Xyy -
 272.11 -
 272.39 -
 271.29(39)

Xzz
538.10
539.70
536.17(46)

ETA
0.00949
0.00943



Øz,CBr
0.59
0.59



 
 






 








* Calculated here from experimental Xaa and Xbb - Xcc = 141.98(55) MHz.

** The product XabXacXbc is positive.

 








 








   







Table 2.  81Br nqcc's in 1-Bromobutane, GA (MHz).  

 







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

Calc (2) was made on this same structure but with empirically corrected C-C and CBr bond lengths.

 









Calc (1)
Calc (2)
Expt. [1]
   







Xaa
129.08
130.43
132.69(22)

Xbb
  - 4.26
  - 4.74
  - 7.37(39) *

Xcc -
 124.82
 -
 125.68
 -
 125.32(39) *

|Xab| **
281.85
282.31
280.1(36)

|Xac|
187.06
186.91
186.5(64)

|Xbc|
146.97
146.42
144.24(68)

 







RMS
2.77 (3.13 %)
2.01 (2.28 %)



RSD
1.38 (0.40 %)
1.38 (0.40 %)



 
 






 








* Calculated here from experimental Xaa and Xbb - Xcc = 117.95(74) MHz.

** The product XabXacXbc is positive.

 












Table 3.  1-Bromobutane, GG.  MP2/6-311+G(3df,3pd) structure parameters (Å and degrees).  Approximate equilibrium bond lengths for C-C and CBr are given in parentheses.
 







 C
 C,1,B1
 C,2,B2,1,A1
 C,3,B3,2,A2,1,D1,0
 Br,4,B4,3,A3,2,D2,0
 H,1,B5,2,A4,3,D3,0
 H,1,B6,2,A5,3,D4,0
 H,1,B7,2,A6,3,D5,0
 H,2,B8,1,A7,3,D6,0
 H,2,B9,1,A8,3,D7,0
 H,3,B10,2,A9,1,D8,0
 H,3,B11,2,A10,1,D9,0
 H,4,B12,3,A11,2,D10,0
 H,4,B13,3,A12,2,D11,0



 B1=1.52335561        (1.5211)
 B2=1.52489962        (1.5226)
 B3=1.51547692        (1.5136)
 B4=1.94490772        (1.9484)
 B5=1.08863794
 B6=1.09098994
 B7=1.08935805
 B8=1.09103878
 B9=1.09041039
 B10=1.09512965
 B11=1.09096375
 B12=1.08596276
 B13=1.08588055
 A1=113.21274924
 A2=114.73157469
 A3=112.07896313
 A4=110.90307539
 A5=111.08637332
 A6=111.38150932
 A7=109.6325222
 A8=109.6610781
 A9=109.19768178
 A10=109.92566148
 A11=112.32398739
 A12=111.5152903
 D1=-55.70938368
 D2=-60.08084371
 D3=-173.75474666
 D4=-53.8212267
 D5=66.79453638
 D6=120.85742939
 D7=-122.24773962
 D8=63.69793816
 D9=-179.04277265
 D10=58.92002465
 D11=-178.25977716
 



 








 













Table 4.  1-Bromobutane, GG.  Rotational constants (MHz), 79Br species.
 




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

r (2) = r (1) but with corrected C-C and CBr bond length.







 r (1)  r (2)   Expt. [1]






A  6133.
  6139.
 6240.618(278)

B  1525.
  1526.
 1463.8266(41)

C  1400.
  1400.
 1352.8742(36)
   
  



 








 








[1] J.Kim, H.Jang, S.Ka, D.A.Obenchain, R.A.Peebles, S.A.Peebles, and J.J.Oh, J.Mol.Spectrosc. 328,50(2016).











S.Ka, J.Kim, H.Jang, and J.J.Oh, Abstract MG03, 70th International Symposium on Molecular Spectroscopy, Champaign-Urbana, 2015.

 








 








2-Bromobutane 2-Bromopropane
 g-1-Bromopropane
 Ethyl Bromide

1-Bromobutane, AA
 1-Bromobutane, GA



 








 








Table of Contents




Molecules/Bromine




 








 













1BrButane_GG.html






Last Modified 26 Sept 2016