BrClCF2						PDF
		Chlorine and Bromine
	Nuclear Quadrupole Coupling Constants
		in Bromochlorodifluoromethane
	Chlorine and bromine nqcc's in bromochlorodifluoromethane were determined by Kisiel et al. [1].  An effective ro molecular structure was derived by Bettens and Brown [2].  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 models for calculation of the nqcc's, which may be taken as estimates of the uncertainty in the calculated nqcc's.
	Table 1.  35Cl nqcc's in 79Br35ClCF2 (MHz).  Calculation was made on ro and ~re structures.     Calc / ro Calc / ~re Expt. [1]     Xaa - 11.38 - 11.76 - 11.2741(53) Xbb - 27.55 - 27.26 - 27.5950(39) Xcc 38.94 39.02 38.8691(39) |Xab| 58.72 58.72 58.370(91)   RMS 0.08 (0.30 %) 0.35 (1.3 %) RSD 0.49 (1.1 %) 0.49 (1.1 %)   Xxx 39.80 39.72 39.503(90) Xyy 38.94 39.02 38.8691(39) Xzz - 78.74 - 78.74 - 78.372(90) ETA - 0.011 - 0.009 - 0.0081(12) Øz,a 48.92 48.76 48.979(6) Øa,CCl 50.39 50.43 Øz,CCl   1.47   1.67
	Table 2.  79Br nqcc's in 79Br35ClCF2 (MHz).  Calculation was made on ro and ~re structures.     Calc / ro Calc / ~re Expt. [1]     Xaa 556.57 548.51 547.0316(34) Xbb - 247.17 - 239.63 - 238.4658(23) Xcc - 309.40 - 308.88 - 308.5658(23) |Xab| 249.88 257.82 258.583(44)   RMS 7.47 (2.0 %) 1.10 (0.30 %) RSD 1.58 (0.39 %) 1.58 (0.39 %)   Xxx - 318.52 - 316.48 - 315.948(24) Xyy - 309.40 - 308.88 - 308.5658(23) Xzz 627.92 625.36 624.513(24) ETA - 0.0145 - 0.0122 - 0.01182(4) Øz,a 15.94 16.60 16.680(2) Øa,CBr 17.30 17.80 Øz,CBr   1.36   1.20
	Table 3.  35Cl nqcc's in 81Br35ClCF2 (MHz).  Calculation was made on ro and ~re structures.     Calc / ro Calc / ~re Expt. [1]     Xaa - 11.06 - 11.43 - 10.9499(39) Xbb - 27.88 - 27.59 - 27.9149(35) Xcc 38.94 39.02 38.8649(35) |Xab| 58.67 58.68 58.319(99)   RMS 0.08 (0.30 %) 0.35 (1.3 %) RSD 0.49 (1.1 %) 0.49 (1.1 %)   Xxx 39.80 39.72 39.500(98) Xyy 38.94 39.02 38.8649(35) Xzz - 78.74 - 78.74 - 78.365(98) ETA - 0.011 - 0.009 - 0.0081(13) Øz,a 49.08 48.92 48.138(7) Øa,CCl 50.55 50.59 Øz,CCl   1.47   1.67
	Table 4.  81Br nqcc's in 81Br35ClCF2 (MHz).  Calculation was made on ro and ~re structures.     Calc / ro Calc / ~re Expt. [1]     Xaa 466.15 459.45 458.1861(23) Xbb - 207.66 - 201.39 - 200.4058(19) Xcc - 258.49 - 258.06 - 257.7776(19) |Xab| 206.90 213.57 214.168(48)   RMS 6.23 (2.0 %) 0.94 (0.31 %) RSD 1.58 (0.39 %) 1.58 (0.39 %)   Xxx - 266.12 - 264.41 - 263.927(26) Xyy - 258.49 - 258.06 - 257.7776(19) Xzz 524.61 522.47 521.705(26) ETA - 0.0145 - 0.0122 - 0.01179(4) Øz,a 15.78 16.44 16.520(2) Øa,CBr 17.14 17.64 Øz,CBr   1.36   1.20
	Table 5.  BrClCF2 Structure parameters, ro [2] (Å and degrees).       ro   ~re CBr 1.9320(44) 1.9253 CCl 1.7358(20) 1.7523 CF 1.3398(20) 1.3288 BrCCl 112.31 111.77 BrCF 108.58 109.26 FCF 106.8 107.76 Z-Matrix Cl C 1 R2 Br 2 R3 1 A3 F 2 R4 3 A4 1   D F 2 R4 3 A4 1 - D                ro    ~re R2 = 1.7358 1.7523 R3 = 1.9320 1.9253 R4 = 1.3398 1.3288 A3 = 112.31 111.774 A4 = 108.58 109.256 D = 122.117 121.166
	[1] Z.Kisiel, E.Białkowska-Jaworska, and L.Pszczółkowski, J.Mol.Spectrosc. 185,71(1997).
	[2] R.P.A.Bettens and R.D.Brown, J.Mol.Spectrosc. 155,55(1992).
	BrClCH2		CH3Cl		CH3Br		CF2Cl2
	CHF2Cl		CF3Cl		CF3Br		CH2Cl2
	CH2FCl		CH2Br2
	Table of Contents
	Molecules/Chlorine
	Molecules/Bromine
						CBrClF2.html
						Last Modified 20 July 2009