CHCl2-CH2Cl
		Chlorine
	Nuclear Quadrupole Coupling Constants
	in 1,1,2-Trichloroethane
	Calculation of the 35Cl nuclear quadrupole coupling constants in CHCl2CH2Cl was made here on ropt   molecular structures given by MP2/6-311+G(3df,3pd) and MP2/aug-cc-pVTZ optimization, each with approximate equilibrium bond lengths.  These nqcc's are given in Tables 1 and 2.  Structure parameters are given in Table 3, equilibrium rotational constants and dipole moments in Table 4, quartic centrifugal distortion constants in Table 5.
	A PE scan at MP2/6-311+G(d,p) level of theory has identified two stable conformers as shown below:
	gauche, C1					trans, Cs
	At MP2/aug-cc-pVTZ opt level of theory, Egauche < Etrans by 5.7 kJ/mol.  Results of calculations made on the trans conformer are given below - for the gauche conformer, click here.
	In Tables 1 and 2, subscripts a,b,c refer to the principal axes of the inertia tensor; subscripts x,y,z to the principal axes of the nqcc tensor.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.
	RSD is the calibration residual standard deviation of the B1LYP/TZV(3df,2p) model for calculation of the efg's/nqcc's.
	Table 1.  Cl(3,4) nqcc's in t-CH35Cl2-CH235Cl (MHz).  Calculation was made on the (1) MP2/6-311+G(3df,3pd) and (2) MP2/aug-cc-pVTZ ropt structures, each with approximate equilibrium bond lengths.  Atomic numbering is shown above.     Calc. (1) Calc. (2) Expt.     Xaa 32.37 32.46 Xbb - 42.38 - 42.01 Xcc 10.01   9.55 Xab ± 23.35 ± 23.14 Xac - 15.09 - 15.11 Xbc ± 46.25 ± 46.53   RSD 0.49 (1.1 %) 0.49 (1.1 %)   Xxx 36.46 36.46 Xyy 39.97 39.96 Xzz - 76.43 - 76.42 ETA 0.0460 0.0458 Øz,CCl 1.09 1.01
	Table 2.  Cl(8) nqcc's in t-CH35Cl2-CH235Cl (MHz).  Calculation was made on the (1) MP2/6-311+G(3df,3pd) and (2) MP2/aug-cc-pVTZ ropt structures, each with approximate equilibrium bond lengths.  Atomic numbering is shown above.     Calc. (1) Calc. (2) Expt.     Xaa - 6.29 - 5.80 Xbb 39.57 39.57 Xcc - 33.28 - 33.77 Xac 55.06 54.96   RSD 0.49 (1.1 %) 0.49 (1.1 %)   Xxx 36.91 36.93 Xyy 39.57 39.57 Xzz - 76.48 - 76.50 ETA 0.0348 0.0346 Øz,a 128.11 127.86 Øa,CCl 127.62 127.37 Øz,CCl     0.49     0.49
	Table 3.  t-CH35Cl2-CH235Cl.  Optimized structure parameters (Å and degrees).  Approximate re bond lengths are shown in parentheses.  Atomic numbering is shown above.    C  C,1,B1  Cl,1,B2,2,A1  Cl,1,B3,2,A2,3,D1,0  H,1,B4,2,A3,3,D2,0  H,2,B5,1,A4,5,D3,0  H,2,B6,1,A5,5,D4,0  Cl,2,B7,1,A6,5,D5,0   MP2/6-311+G(3df,3pd)    MP2/aug-cc-pVTZ  B1=1.51463961      (1.5128)  B2=1.76392865      (1.7683)  B3=1.76392865      (1.7683)  B4=1.0863115  B5=1.08700971  B6=1.08700971  B7=1.76157334      (1.7659)  A1=111.50650969  A2=111.50650969  A3=108.65087072  A4=108.67060341  A5=108.67060341  A6=113.27671857  D1=125.08561396  D2=-117.45719302  D3=-59.87022498  D4=59.87022498  D5=180.  B1=1.51368202      (1.5120)  B2=1.77129534      (1.7680)  B3=1.77129534      (1.7680)  B4=1.08690885  B5=1.08775763  B6=1.08775763  B7=1.76982853      (1.7666)  A1=111.43329973  A2=111.43329973  A3=109.10847954  A4=108.92612532  A5=108.92612532  A6=113.02603149  D1=124.65753115  D2=-117.67123442  D3=-60.12418154  D4=60.12418154  D5=180.
	Table 4.  t-CH35Cl2-CH235Cl.  Rotational Constants (MHz) and Dipole Moments (D).   r (1) = MP2/6-311+G(3df,3pd) ropt with approximate re bond lengths. r (2) = MP2/aug-cc-pVTZ ropt with approximate re bond lengths.     Calc. r (1) Calc. r (2)    Expt. A 2733.2 2736.8 B 1950.6 1959.3 C 1346.0 1352.6   |µa| * 0.096 0.096 |µb| * 0 (symmetry) 0 (symmetry) |µc| * 2.57 2.57 *  B1LYP/TZV(3df,2p) on r(1) and r(2) structures.
	Table 5.  t-CH35Cl2-CH235Cl.  B3LYP/cc-pVTZ Quartic Centrifugal Distortion Constants (kHz).   Delta_J 0.467 D_J 0.283 Delta_JK 2.06 D_JK 3.16 Delta_K - 1.82 D_K - 2.74 delta_J 0.127 d_1 - 0.127 delta_K 1.39 d_2 - 0.0916
	1,1,2-Trichlorotrifluoroethane			Chlorofluoroethanes		g-1,1,2-Trichloroethane
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						Last Modified 11 Nov 2013