1,1,1-Chloro-2,2,2-fluoroethane

CF₃CCl₃

Chlorine

Nuclear Quadrupole Coupling Constants

in 1,1,1-Trichloro-2,2,2-trifluoroethane

Chlorine nqcc's in all four possible chlorine isotopic species of 1,1,1-trichloro-2,2,2-trifluoroethane were determined by Kisiel et al. [1].

Calculation of the chlorine nqcc's was made on an approximate equilibrium molecular structure (~r_e) derived ab initio (see below), and on an r_e^SE structure derived in Ref. [1]. These are compared with the experimental nqcc's in Tables 1,3 - 7. Structure parameters are given in Table 2.

In Tables 1,3 - 7, suscripts a,b,c refer to principal inertial axes, x,y,z to principal axes of the nqcc tensor. Ø (degrees) is the angle between its subscripted parameters. ETA = (X_xx - X_yy)/X_zz.

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 B1LYP/TZV(3df,2p) computional model for calculation of the nqcc's.


Table 1. ³⁵Cl(1) nqcc's in CF₃C³⁵Cl₃ (MHz). Calculation was made on ~r_e and r_e^SE structures.

		Calc / ~r_e		Calc / r_e^SE		Expt. [1]

X_aa		27.52		27.44		27.55110(58)
X_bb	-	69.54	-	69.52	-	69.44020(91)
X_cc		42.02		42.09		41.88910(91)
X_ab		37.94		38.16	-	37.760(12) *

RSM		0.10 (0.21 %)		0.14 (0.30 %)
RSD		0.49 (1.1 %)		0.49 (1.1 %)

X_xx		40.59		40.65		40.5177(74)
X_yy		42.02		42.09		41.88910(91)
X_zz	-	82.61	-	82.74	-	82.4069(74)
ETA		0.017		0.017		0.01664(9)
Ø_z,a		70.99		70.90		71.0475(44)
Ø_a,CCl		71.40		71.32
Ø_z,CCl		0.41		0.42

* Here, and in Tables that follow, differences in algebraic signs of the off-diagonal components are due only to differences in orientation of the moleule with respect to positive/negative sense of the inertial axes. Only magnitudes of these components are to be compared.

Derivation of Approximate Equilibrium Molecular Structure: The molecular structure was optimized at the MP2/6-311+G(d,p) level of theory, the optimized CC single bond length then corrected using the equation obtained from linear regression analysis of the data given in Table IX of Ref. [2]. Likewise, the optimized CF bond lengths were corrected by regression analysis of the data given in Table VI of Ref. [3]. For the CCl bonds, the structure was optimized at the MP2/6-311+G(2d,p) level and corrected by linear regression analysis of the data given in Table 4 of Ref. [4]. Interatomic angles used in the calculation are those given by B3P86/6-311+G(3d,3p) partial optimization (with corrected bond lengths held fixed).


Table 2. Molecular structure parameters (Å and degrees), ~r_e and r_e^SE [1],

		~r_e	r_e^SE
	CCl	1.7546	1.7586(20)
	CC	1.5408	1.5493(12)
	CF	1.3254	1.3251(21)
	CCF	110.42	110.19(31)
	CCCl	108.60	108.68(21)


Table 3. ³⁷Cl(1) nqcc's in CF₃C³⁷Cl³⁵Cl₂ (MHz). Calculation was made on ~r_e and r_e^SE structures.

		Calc / ~r_e		Calc / r_e^SE		Expt. [1]

X_aa		18.77		18.72		18.8698(16)
X_bb	-	51.88	-	51.89	-	51.8846(17)
X_cc		33.12		33.17		33.0148(17)
X_ab		33.30		33.44	-	33.180(44)

RSM		0.08 (0.24 %)		0.13 (0.36 %)
RSD		0.49 (1.1 %)		0.49 (1.1 %)

X_xx		31.99		32.04		31.995(30)
X_yy		33.12		33.17		33.0148(17)
X_zz	-	65.11	-	65.21	-	65.010(30)
ETA		0.017		0.017		0.0157(5)
Ø_z,a		68.34		68.28		68.418(19)
Ø_a,CCl		68.75		68.70
Ø_z,CCl		0.41		0.42


Table 4. ³⁵Cl(2,3) nqcc's in CF₃C³⁷Cl³⁵Cl₂ (MHz). Calculation was made on ~r_e and r_e^SE structures.

		Calc / ~r_e		Calc / r_e^SE		Expt. [1]

X_aa		29.24		29.15		29.2276(9)
X_bb		12.41		12.47		12.3792(15)
X_cc	-	41.65	-	41.62	-	41.6068(15)
X_ab	-	18.27	-	18.39		18.130(35)
X_ac	-/+	30.59	-/+	30.80	-/+	30.459(24)
X_bc	-/+	49.77	-/+	49.79	+/-	49.6361(24)

RSM		0.03 (0.11 %)		0.07 (0.24 %)
RSD		0.49 (1.1 %)		0.49 (1.1 %)

X_xx		40.59		40.65		40.486(16)
X_yy		42.02		42.09		41.8875(25)
X_zz	-	82.61	-	82.74	-	82.373(16)
ETA		0.017		0.017		0.0170(10)
Ø_z,CCl		0.41		0.42


Table 5. ³⁵Cl(1) nqcc's in CF₃C³⁵Cl³⁷Cl₂ (MHz). Calculation was made on ~r_e and r_e^SE structures.

		Calc / ~r_e		Calc / r_e^SE		Expt. [1]

X_aa		30.58		30.50		30.5494(41)
X_bb		42.02		42.09		41.8697(85)
X_cc	-	72.60	-	72.59	-	72.4191(85)
X_ac		33.65		33.91	-	33.72(19)

RSM		0.14 (0.29 %)		0.16 (0.33 %)
RSD		0.49 (1.1 %)		0.49 (1.1 %)

X_xx		40.59		40.65		40.61(10)
X_yy		42.02		42.09		41.8697(85)
X_zz	-	82.61	-	82.74	-	82.48(10)
ETA		0.017		0.017		0.0153(13)
Ø_z,a		73.44		73.33		73.389(75)
Ø_a,CCl		73.85		73.75
Ø_z,CCl		0.41		0.42


Table 6. ³⁷Cl(2,3) nqcc's in CF₃C³⁵Cl³⁷Cl₂ (MHz). Calculation was made on ~r_e and r_e^SE structures.

		Calc / ~r_e		Calc / r_e^SE		Expt. [1]

X_aa		20.39		20.33		20.4401(27)
X_bb	-	32.82	-	32.80	-	32.7801(48)
X_cc		12.43		12.47		12.3399(48)
X_ab	-/+	27.50	-/+	27.64	-/+	27.06(17)
X_ac	-	15.35	-	15.43		15.33(20)
X_bc	-/+	36.93	-/+	36.95	+/-	36.860(17)

RSM		0.07 (0.31 %)		0.10 (0.46 %)
RSD		0.49 (1.1 %)		0.49 (1.1 %)

X_xx		31.99		32.04		31.77(11)
X_yy		33.12		33.17		33.011(43)
X_zz	-	65.11	-	65.21	-	64.79(11)
ETA		0.017		0.017		0.0191(19)
Ø_z,CCl		0.41		0.42


Table 7. ³⁷Cl(1) nqcc's in CF₃C³⁷Cl₃ (MHz). Calculation was made on ~r_e and r_e^SE structures.

		Calc / ~r_e		Calc / r_e^SE		Expt. [1]

X_aa		21.68		21.62		21.7161(30)
X_bb	-	54.80	-	54.79	-	54.7179(13)
X_cc		33.12		33.17		33.0035(13)
X_ab		29.90		30.07	-	29.60(13)

RSM		0.08 (0.23 %)		0.12 (0.32 %)
RSD		0.49 (1.1 %)		0.49 (1.1 %)

X_xx		31.99		32.04		31.838(74)
X_yy		33.12		33.17		33.0035(13)
X_zz	-	65.11	-	65.21	-	64.839(74)
ETA		0.017		0.017		0.0180(12)
Ø_z,a		70.99		70.90		71.123(61)
Ø_a,CCl		71.40		71.32
Ø_z,CCl		0.41		0.42

[1] Z.Kisiel, L.Pszczółkowski, E.Białkowska-Jaworska, M.Jaworski, I.Uriarte, F.J.Basterretxea, and E.J.Cocinero, J.Mol.Spectrosc. 352,1(2018).

[2] J.Demaison, J.Cosléou, R.Bocquet, and A.G.Lesarri, J.Mol. Spectrosc. 167,400(1994).

[3] R.M.Villamañan, W.D.Chen, G.Wlodarczak, J.Demaison, A.G.Lesarri, J.C.López, and J.L.Alonso, J.Mol.Spectrosc. 171,223(1995).

[4] I.Merke, L.Poteau, G.Wlodarczak, A.Bouddou, and J.Demaison, J.Mol.Spectrosc. 177,232(1996).

CFCl₃

SiHCl₃

CH₃CCl₃

OPCl₃

NCl₃

PCl₃

AsCl₃

SPCl₃

CH₃Cl

CH₂Cl₂

CHCl₃

Table of Contents

Molecules/Chlorine

CF3CCl3.html

Last Modified 21 July 2018