BrClCH2						PDF
		Chlorine and Bromine
	Nuclear Quadrupole Coupling Constants
		in Bromochloromethane
	Chlorine and bromine nqcc's in bromochloromethane were measured by Niide and Ohkoshi [1], who also derived  an effective ro molecular structure. Calculation of the nqcc's was made here on this structure, and on an ~re structure given by MP2/aug-cc-pVTZ optimization with empirically corrected CBr, CCl, and CF bond lengths.  Calculated and experimental nqcc's are compared in Tables 1-4.  Structure parameters are given in Table 5.
	In Tables 1 - 4, 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 mean square difference between calculated and experimental diagonal nqcc (percentage of average of absolute experimental nqcc's).  RSD is the residual standard deviation of the calibration of the computional model for calculation of the nqcc's.
	Table 1.  35Cl nqcc's in 79Br35ClCH2 (MHz).  Calculation was made on ro and ~re structures.     Calc / ro Calc / ~re Expt. [1]     Xaa - 35.69 - 36.06 - 33.64(70) Xbb - 4.89 - 4.42 - 5.79(41) Xcc 40.58 40.48 39.43(81) |Xab| 54.25 53.84 53.7(52)   RMS 1.45 (5.5 %) 1.72 (6.5 %) RSD 0.49 (1.1 %) 0.49 (1.1 %)   Xxx 36.10 35.87 35.76 Xyy 40.58 40.48 39.43 Xzz - 76.68 - 76.35 - 75.19 ETA 0.058 0.060 0.04880 Øz,a 37.08 36.81 37.72 Øa,CCl 38.05 37.89 Øz,CCl   0.97   1.08
	Table 2.  79Br nqcc's in 79Br35ClCH2 (MHz).  Calculation was made on ro and ~re structures.     Calc / ro Calc / ~re Expt. [1]     Xaa 383.01 385.58 383.33(59) Xbb - 75.15 - 79.02 - 75.80(37) Xcc - 307.86 - 306.56 - 307.53(69) |Xab| 373.28 368.74 372.4(13)   RMS 0.46 (0.18 %) 2.43 (0.91 %) RSD 1.58 (0.39 %) 1.58 (0.39 %)   Xxx - 284.03 - 282.54 - 283.70 Xyy - 307.86 - 306.56 - 307.53 Xzz 591.90 589.09 591.23 ETA 0.0403 0.0401 0.04030 Øz,a 29.23 28.90 29.17 Øa,CBr 29.64 29.45 Øz,CBr   0.41   0.55
	Table 3.  35Cl nqcc's in 81Br35ClCH2 (MHz).  Calculation was made on ro and ~re structures.     Calc / ro Calc / ~re Expt. [1]     Xaa - 35.62 - 35.99 - 34.82(48) Xbb - 4.79 - 4.49 - 5.39(28) Xcc 40.58 40.48 40.21(55) |Xab| 54.27 53.86 57.4(17)   RMS 0.56 (2.1 %) 0.86 (3.2 %) RSD 0.49 (1.1 %) 0.49 (1.1 %)   Xxx 36.10 35.87 39.15 Xyy 40.58 40.48 40.21 Xzz - 76.68 - 76.35 - 79.36 ETA 0.058 0.060 0.01335 Øz,a 37.11 36.85 37.80 Øa,CCl 38.08 37.93 Øz,CCl   0.97   1.08
	Table 4.  81Br nqcc's in 81Br35ClCH2 (MHz).  Calculation was made on ro and ~re structures.     Calc / ro Calc / ~re Expt. [1]     Xaa 320.43 322.57 317.73(69) Xbb - 63.22 - 66.45 - 62.13(39) Xcc - 257.21 - 256.12 - 255.60(79) |Xab| 311.59 307.80 311.6(8)   RMS 1.92 (0.91 %) 3.76 (1.77 %) RSD 1.58 (0.39 %) 1.58 (0.39 %)   Xxx - 237.30 - 236.05 - 237.12 Xyy - 257.21 - 256.12 - 255.60 Xzz 494.51 492.17 492.72 ETA 0.0403 0.0408 0.03750 Øz,a 29.19 28.86 29.32 Øa,CBr 29.60 29.41 Øz,CBr   0.41   0.55
	Table 5.  BrClCH2 Structure parameters, ro [1] and ~re (Å and degrees/minutes).      ro   ~re CBr 1.930 1.9274 CCl 1.768 1.7615 CH 1.074 1.0824 BrCCl 112o19' 112.66 ClCH 108o40' 108.55 HCH 110o56' 112.00 Z-Matrix Br C 1 R2 Cl 2 R3 1 A3 H 2 R4 3 A4 1   D H 2 R4 3 A4 1 - D                ro    ~re R2 = 1.930 1.9274 R3 = 1.768 1.7615 R4 = 1.074 1.0824 A3 = 112.3167 112.66 A4 = 108.6667 108.55 D = 119.5952 119.0196
	[1] Y.Niide and I.Ohkoshi, J.Mol.Spectrosc. 136,17(1989).
	BrClCF2		CH3Cl		CH3Br		CF2Cl2
	CHF2Cl		CF3Cl		CF3Br		CH2Cl2
	CH2FCl		CH2Br2
	Table of Contents
	Molecules/Chlorine
	Molecules/Bromine
						CBrClH2.html
						Last Modified 21 July 2009