BrNCO


 
 
 
 


Bromine and Nitrogen


Nuclear Quadrupole Coupling Constants

in Bromine Isocyanate

 







 
 
Calculation of the chlorine nqcc's in bromine isocyanate was made on the ro and rz structures of Hensel et al. [1].  These are compared with the experimental nqcc's [1,2] in Tables 1 - 5.  Structure parameters are given in Table 6.
 
In Tables 1 - 5, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  The nqcc y-axis is chosen coincident with the inertia c-axis, these are perpendicular to the molecular plane.  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.  RSD is the standard deviation of the residuals of the calibration of the models for calculation of the nqcc's, which may be taken as an estimate of the uncertainty in the calculated nqcc's.
 
 
 
   






Table 1.  79Br nqcc's in BrNCO (MHz).  Calculation was made on the molecular ro and rz structures.
   







Calc. / ro
Calc. / rz
Expt. [2]
   





Xaa 619.17 619.54 608.41(52)
Xbb - 170.26 - 172.03 - 164.16
Xcc - 448.91 - 447.51 - 444.25(26)
|Xab| 556.49 554.02 549.67(12)
 
RMS 7.63 (1.88 %) 8.09 (1.99 %)
RSD 1.58 (0.39 %) 1.58 (0.39 %)
 
Xxx - 457.81 - 457.12 - 449.70(36)
Xyy - 448.91 - 447.51 - 444.25(26)
Xzz 906.72 904.63 893.95(46)
ETA - 0.0098 - 0.0106
Øz,a 27.33 27.23 27.45(1)
Øa,BrN 28.76 28.72
Øz,BrN   1.43   1.49
 

 
 
   






Table 2.  81Br nqcc's in BrNCO (MHz).  Calculation was made on the molecular ro and rz structures.
   







Calc. / ro
Calc. / rz
Expt. [2]
   





Xaa 517.96 518.26 508.49(52)
Xbb - 142.92 - 144.38 - 132.98
Xcc - 375.05 - 373.88 - 375.51(31)
|Xab| 464.46 462.40 458.60(12)
 
RMS 7.93 (2.34 %) 8.72 (2.57 %)
RSD 1.38 (0.40 %) 1.38 (0.40 %)
 
 
 
   






Table 3.  Bromine nqcc's in BrNC18O (MHz).  Calculation was made on the molecular ro and rz structures.
   







Calc. / ro
Calc. / rz
Expt. [1]
   





Xaa (79Br) 609.22 609.66 598.3(14)
Xbb - 160.31 - 162.15 - 154.15
Xcc - 448.91 - 447.51 - 444.14(35)
|Xab| 563.42 560.95 556.06(25)
 
RMS 7.75 (1.94 %) 8.26 (2.07 %)
RSD 1.58 (0.39 %) 1.58 (0.39 %)
 
Xaa (81Br) 509.67 510.03 500.2(17)
Xbb - 134.62 - 136.15 - 128.96
Xcc - 375.05 - 373.88 - 371.24(43)
|Xab| 470.25 468.19 464.28(38)
 
RMS 6.74 (2.02 %) 7.19 (2.16 %)
RSD 1.38 (0.40 %) 1.38 (0.40 %)
 
 
 
   






Table 4.  14N nqcc's in 79BrNCO (MHz).  Calculation was made on the molecular ro and rz structures.
   







Calc. / ro
Calc. / rz
Expt. [2]
   





Xaa 3.706 3.755 5.09(78)
Xbb - 0.893 - 0.916 - 1.64
Xcc - 2.813 - 2.840 - 3.45
|Xab| 1.729 1.680
 
RMS 0.98 (29 %) 0.94 (28 %)
RSD 0.030 (1.3 %) 0.030 (1.3 %)
 
Xxx - 1.471 - 1.457
Xyy - 2.813 - 2.840
Xzz 4.284 4.297
ETA 0.313 0.322
Øz,a 18.47 17.87
Øa,BrN 28.76 28.72
Øz,BrN 10.28 10.85
 
 
 
   






Table 5.  14N nqcc's in 81BrNCO (MHz).  Calculation was made on the molecular ro and rz structures.
   







Calc. / ro
Calc. / rz
Expt. [2]
   





Xaa 3.709 3.758 4.75(51)
Xbb - 0.896 - 0.918 - 1.42
Xcc - 2.813 - 2.840 - 3.33
|Xab| 1.726 1.677
 
RMS 0.74 (23 %) 0.70 (22 %)
RSD 0.030 (1.3 %) 0.030 (1.3 %)
 
 
 
Table 6.  BrNCO.  Molecular structure parameters (Å and degrees).  
 
 ro [1]  rz [1]

 		 BrN 1.8617(23) 1.85565(73)
NC 1.2166(40) 1.2224(15)
CO 1.1692(13) 1.16496(53)
BrNC 117.38(42) 117.99(14)
NCO 172.33(44) 173.13(15)

 
 
ClNCO BrNO ClNO CH3CH2NCO
 
 

[1] K.D.Hensel, M.E.Lam, and M.C.L.Gerry, J.Mol.Spectrosc. 151,184(1992).
[2] H.M.Jemson, W.Lewis-Bevan, N.P.C.Westwood, and M.C.L.Gerry, J.Mol.Spectrosc. 118,481(1986).
 

 








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Molecules/Bromine



Molecules/Nitrogen
 

 













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Last Modified 2 Feb 2008