Br(CH3)CN2


















 





 





Bromine and Nitrogen


Nuclear Quadrupole Coupling Constants


in Bromomethyldiazirine



 








 








The rotational spectra of Br(CH3)NH2 was assigned by Wollrab [1].  Bromine nuclear quadrupole coiupling constants were measured.


 









Calculation of Br and 14N nqcc's was made here on molecular structures given by MP2/6-311+G(3df,3pd) and MP2/aug-cc-pVTZ optimization.  These are compared with the experimental values in Tables 1 and 2.  Structure parameters are given in Table 3, rotational constants in Table 4.












In Tables 1 and 2, 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).  In Table 1, RSD is the calibration residual standard deviation of the B1LYP/TZV(3df,4p) model for calculation of bromine efg's/nqcc's; and in Table 2, of the B3PW91/6-311+G(df,pd) model for nitrogen.






















   









Table 1.  Bromine nqcc's in Br(CH3)CN2 (MHz).  Calculation was made on (1) MP2/6-311+G(3df,3pd) and (2) MP2/aug-cc-pVTZ optimized molecular structures.

   












Calc (1)

Calc (2)
Expt [1]
   









79Br Xaa
537.77

534.58

539.8(80)



Xbb -
280.43
-
279.15
-
279.4(60)



Xcc -
257.34
-
255.44
-
260.4(80)



Xab
110.99

113.26















RMS
2.20 (0.61 %)

4.16 (1.16 %)





RSD
1.58 (0.39 %)

1.58 (0.39 %)



 








81Br Xaa
449.41

446.75

451.1(80)



Xbb -
234.41
-
233.34
-
232.3(60)



Xcc -
214.00
-
213.41
-
218.8(80)



Xab
  92.30

  94.18















RMS

2.70 (0.90 %)

4.04 (1.34 %)





RSD

1.38 (0.40 %)
1.38 (0.40 %)














 








 









   









Table 2.  Nitrogen nqcc's in 79Br (CH3)CN2 (MHz).  Calculation was made on (1) MP2/6-311+G(3df,3pd) and (2) MP2/aug-cc-pVTZ optimized molecular structures.

   












Calc (1)

Calc (2)
Expt.

   









14N Xaa
2.156

2.151





Xbb
0.119

0.108





Xcc -
2.275
-
2.259





Xab
2.354

2.340





Xac -/+
0.400
-/+
0.392





Xbc +/-
0.514
+/-
0.514















RSD
0.030 (1.3 %)
0.030 (1.3 %)



 









 









 


Table 3.  Br(CH3)CN2:  ropt(1) = MP2/6-311+G(3df,3pd) and ropt(2) = MP2/aug-cc-pVTZ optimized molecular structure parameters ( and degrees).
 



 C
 N,1,B1
 N,2,B2,1,A1
 C,1,B3,2,A2,3,D1,0
 H,4,B4,1,A3,2,D2,0
 H,4,B5,1,A4,2,D3,0
 H,4,B6,1,A5,2,D4,0
  Br,1,B7,2,A6,3,D5,0






     ropt(1)      ropt(2)
 




 B1=1.45570806
 B2=1.26029741
 B3=1.49295003
 B4=1.08819458
 B5=1.08819458
 B6=1.0888385
 B7=1.90434329
 A1=64.34944999
 A2=120.79114032
 A3=110.34297889
 A4=110.34297889
 A5=109.31072
 A6=116.32276468
 D1=-106.62813908
 D2=150.22284213
 D3=-89.70435554
 D4=30.25924329
 D5=103.74313606
 B1=1.45838893
 B2=1.26268865
 B3=1.491804
 B4=1.08906743
 B5=1.08906743
 B6=1.08929089
 B7=1.89720481
 A1=64.34791936
 A2=121.09319774
 A3=110.20939764
 A4=110.20939764
 A5=109.44530188
 A6=116.08544534
 D1=-106.83522141
 D2=150.43334848
 D3=-89.69939438
 D4=30.36697705
 D5=103.59839241



 








 








 



Table 4.  79Br(CH3)CN2:  ropt(1) = MP2/6-311+G(3df,3pd) and ropt(2) = MP2/aug-cc-pVTZ  rotational constants (MHz).
 





 ropt(1) ropt(2) Expt [1]






A
 6584.
 6560.


B
 2405.
 2423.


C
 1933.
 1943.



 








 








[1]  J.E.Wollrab, J.Chem.Phys. 53(4),1543(1970).


 








 








Diazirine
Methyldiazirine
Dimethyldiazirine


Chloromethyldiazirine

















 









Table of Contents




Molecules/Nitrogen




 








 













BrCH3CN2.html






Last Modified 10 Jan 2017