BrCH2CH2CH2CH3
































 









Bromine


Nuclear Quadrupole Coupling Constants

in 1-Bromobutane, GA

 








 








Calculation of the bromine nqcc tensors in 1-bromobutane, GA 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 GG 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, 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
  86.47
  87.68
  87.17(10)

Xbb
167.75
166.92
166.53(6) *

Xcc -
 254.22
 -
 254.60
 -
 253.70(6) *

|Xab| **
396.63
397.26
394.70(44)

|Xac|
  72.31
  72.25
  72.26(236)

|Xbc|
  87.68
  87.38
  87.38(18)

 







RMS
0.86 (0.62 %)
0.70 (0.42 %)



RSD
1.58 (0.39 %)
1.58 (0.39 %)



 







Xxx -
 265.94
 -
 266.25
 -
 264.89(197)

Xyy -
 276.07 -
 276.37 -
 274.83(154)

Xzz
542.01
542.62
539.71(63)

ETA
0.0187
0.0187



Øz,CBr
0.68
  0.69



 
 






 








* Calculated here from experimental Xaa and Xbb - Xcc = 420.24(6) 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
  73.29
  74.30
  73.83(93)

Xbb
139.17
138.48
138.18(47) *

Xcc -
 212.46
 -
 212.78
 -
 212.01(47) *

|Xab| **
331.51
332.02
329.92(43)

|Xac|
  60.37
  60.32
  59.81(271)

|Xbc|
  72.99
  72.74
  74.04(149)

 







RMS
0.70 (0.49 %)
0.55 (0.39 %)



RSD
1.38 (0.40 %)
1.38 (0.40 %)



 
 






 








* Calculated here from experimental Xaa and Xbb - Xcc = 350.20(6) MHz.

** The product XabXacXbc is positive.

 












Table 3.  1-Bromobutane, GA.  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=1.52289887      (1.5207)
 B2=1.52149911      (1.5194)
 B3=1.51457813      (1.5128)
 B4=1.94513103      (1.9487)
 B5=1.08862938
 B6=1.08988951
 B7=1.09009735
 B8=1.09030692
 B9=1.09278722
 B10=1.09492297
 B11=1.0919521
 B12=1.08740424
 B13=1.08591195
 A1=111.82020701
 A2=113.9918636
 A3=111.99537622
 A4=111.37672582
 A5=110.70551647
 A6=111.0296175
 A7=109.8849177
 A8=109.90443297
 A9=109.15765211
 A10=110.03728222
 A11=111.75077351
 A12=111.99086611
 D1=-178.26098457
 D2=-66.16588599
 D3=179.89413087
 D4=-60.10095159
 D5=59.60411974
 D6=121.53564413
 D7=-121.20162849
 D8=-58.68645136
 D9=58.45854835
 D10=52.47569997
 D11=175.58933436
 



 








 













Table 4.  1-Bromobutane, GA.  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  8258.
  8254.
 8196.3730(66)

B  1223.
  1223.
 1207.2681(105)

C  1122.
  1122.
 1107.67707(78)
   
  



 








 








[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, GG



 








 








Table of Contents




Molecules/Bromine




 








 













1BrButane_GA.html






Last Modified 26 Sept 2016