CH2Cl2
		Chlorine and Deuterium
	Nuclear Quadrupole Coupling Constants
		in Dichloromethane
	35Cl nqcc's in dichloromethane (methylene chloride) were first measured by Myers and Gwinn [1], by Flygare and Gwinn [2], and recently revisited by Kisiel et al. [3]. Equilibrium structures were reported by Davis et al. [4], and Duncan [5].  The rmrho structure was derived by Berry and Harmony [6].
	Chlorine and deuterium nqcc's were calculated on each of the above structures.  These are compared with the experimental values [3] for chlorine in Tables 1 - 3.  Calculated deuterium nqcc's are given in Table 4.  The molecular structures are compared in Tables 5.
	In Tables 1 - 3, 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).  RSD is the calibration residual standard deviation for the B1LYP/TZV(3df,2p) model for calculation of the chlorine nqcc's.
	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 ClCCl plane.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.
	Table 1. Chlorine nqcc's in CH2Cl2 (MHz).  Calculation was made on the equilibrium structure of Davis et al. [4].     Calc. Expt. [3]     35Cl Xaa - 41.94 - 41.7418(11) Xbb   1.87   1.8004(12) Xcc 40.07 39.9414(12) Xab ± 51.38 ± 50.93(23)   RMS 0.14 (0.51 %) RSD 0.49 (1.1 %)
	Table 2. Chlorine nqcc's in CH2Cl2 (MHz).  Calculation was made on the equilibrium structure of Duncan et al. [5].     Calc. Expt. [3]     35Cl Xaa - 41.88 - 41.7418(11) Xbb   1.81   1.8004(12) Xcc 40.06 39.9414(12) Xab ± 51.35 ± 50.93(23)   RMS 0.10 (0.38 %) RSD 0.49 (1.1 %)   Xxx 35.77 35.41(21) Xyy 40.06 39.9414(12) Xzz - 75.84 - 75.35(21) ETA 0.057 0.060(3) Øz,a 33.48 33.43(5) Øa,CCl 34.02 34.11(2) Øz,CCl   0.54     37Cl Xaa - 33.00 Xbb   1.43 Xcc 31.58 Xab ± 40.47
	The angle between principal z-axes is 1.08o larger than the ClCCl angle.  This is typical of the XCl2 dichloride moiety.
	Table 3. Chlorine nqcc's in CH2Cl2 (MHz).  Calculation was made on the rmrho structure of Berry and Harmony [6].     Calc. Expt. [3]     35Cl Xaa - 42.24 - 41.7418(11) Xbb   2.19   1.8004(12) Xcc 40.04 39.9414(12) Xab ± 51.12 ± 50.93(23)   RMS 0.37 (1.3 %) RSD 0.49 (1.1 %)
	Table 4.  Deuterium nqcc's in CD2Cl2 (kHz).  Calculation was made on the molecular structures of Davis et al. [4],  Duncan [5], and Berry and Harmony [6].     Calc. [4] Calc. [5] Calc. [6]     Xaa - 85.6 - 89.8 - 86.9 Xbb   - 7.7   - 9.1   - 8.4 Xcc   93.3   98.9   95.3 Xbc ± 126.4 ± 131.7 ± 127.9   Xxx - 93.3 - 97.5 - 94.6 Xyy - 85.6 - 89.8 - 86.9 Xzz 178.9 187.2 181.4 ETA - 0.043 - 0.041 - 0.042 Øz,b 55.89 56.14 56.04 Øb,CD 55.80 56.05 55.95 Øz,CD  0.09   0.09   0.09
	Table 5. Molecular structure parameters (Å and degrees). re [4] re [5] rmrho [6] CCl 1.7648 1.766 1.7636 CH 1.0874 1.080 1.0851 ClCCl 112.03 111.96 112.25 HCH 111.51 112.10 111.90
	[1] R.J.Myers and W.D.Gwinn, J.Chem.Phys. 20,1420(1952).
	[2] W.H.Flygare and W.D.Gwinn, J.Chem.Phys. 36,787(1962).
	[3] Z.Kisiel, J.Kosarzewski, and L.Pszczólkowski, Acta Physica Polonica A, 92,507(1997).
	[4] A.W.Davis, A.G.Robiette, and M.C.L.Gerry, J.Mol.Spectrosc. 85,399(1981).
	[5] J.L.Duncan, J.Mol.Struct. 158,169(1987).
	[6] R.J.Berry and M.D.Harmony, Struct.Chem. 1,49(1989).
	"Theoretical Investigation of the Nuclear Quadrupole Interaction of CH3Cl, CH2Cl2 and CHCl3" G.Frantz, H.Dufner, and P.C.Schmidt, Z.Naturforsch. 49a,116(1993).
	CH3Cl		CHCl3		CF2Cl2		CF3Cl
	CD3F		CD2F2		CDF3		CD2Br2
	CD3CN		CD2(CN)2		CH3D		CD3Br
	Table of Contents
	Molecules/Chlorine
	Molecules/Deuterium
	Summary/Methyls  Deuterium nqcc's in the substituted methanes.
						CH2Cl2.html
						Last Modified 9 April 2004