CH2Br2
		Bromine and Deuterium
	Nuclear Quadrupole Coupling Constants
		in Dibromomethane
	Bromine nqcc's in dibromomethane (methylene bromide) have been measured by Niide et al. [1].  An equilibrium structure was determined by Davis and Gerry [2].  An earlier determination of the nqcc's and structure (ro/rs) was made by Chadwick and Millen [3].
	Calculation of the bromine - and deuterium - nqcc's was made here on the equilibrium structure.  Calculated bromine nqcc's are compared with the experimental values in Tables 1 and 2.  Calculated deuterium nqcc's are given in Table 3.  Equilibrium structure parameters are given in Table 4.
	In Tables 1 - 3, the subscripts a,b,c refer to the principal axes of the inertia tensor.   Subscripts x,y,z refer to the principal axes of the nqcc tensor.  The nqcc y-axis is chosen coincident with the c-axis.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.
	RMS is the root measn square difference between calculated and experimental diagonal nqcc.  RSD is the residual standard deviation of the calibration of the computional model for calculation of the nqcc's.
	Table 1.  79Br nqcc's in CH279Br81Br (MHz).     Calc. Expt. [1]     79Br Xaa 335.90 335.21(42) Xbb - 26.40 - 24.93(24) Xcc - 309.50 - 310.28(48) |Xab| 401.16 402.12(79)   RMS 1.04 (0.46 %) RSD 1.58 (0.39 %)   Xxx - 285.42 - 285.46 Xyy - 309.50 - 310.28 Xzz 594.92 595.74 ETA 0.0405 0.04166 Øz,b 57.15 57.07 Øb,CBr 56.28 Øz,CBr   0.87
	Table 2.  81Br nqcc's in CH279Br81Br (MHz).     Calc. Expt. [1]     81Br Xaa 281.65 281.90(43) Xbb - 23.07 - 22.32(24) Xcc - 258.58 - 259.58(49) |Xab| 334.70 333.65(95)   RMS 0.74 (0.39 %) RSD 1.38 (0.40 %)   Xxx - 238.46 - 236.90 Xyy - 258.58 - 259.58 Xzz 497.04 496.48 ETA 0.0405 0.04568 Øz,b 57.24 57.25 Øb,CBr 56.36 Øz,CBr   0.88
	Table 3.  Deuterium nqcc's in CD2Br2 (kHz).     Calc. Expt.     2H Xaa - 88.0 Xbb   - 9.9 Xcc   97.9 Xbc ± 127.3   RSD 1.1 (0.86 %)   Xxx - 94.2 Xyy - 88.0 Xzz 182.2 ETA - 0.034 Øz,b 56.47 Øb,CD 56.22 Øz,CD   0.25
	Table 4.  Molecular structure parameters, re [2] (Å and degrees).
				CBr		1.9235
				CH		1.0845
				HCH		112.43
				BrCBr		112.64
	[1] Y.Niide, H.Tanaka, and I.Ohkoshi, J.Mol.Spectrosc. 139,11(1990).
	[2] R.W.Davis and M.C.L.Gerry, J.Mol.Spectrosc. 109,269(1985).
	[3] D.Chadwick and D.J.Millen, Chem.Phys.Lett. 5,407(1970); Trans. Faraday Soc. 67,139(1971); 67,1551(1971); J.Mol.Struct. 25,216(1975).
	CH3Br		CF3Br		CD2Cl2		CD2F2
	CH3CH2Br
	Table of Contents
	Molecules/Bromine
	Molecules/Deuterium
	Summary/Methyls  Deuterium nqcc's in the substituted methanes.
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						Last Modified 2 June 2003