1-Iodohexane AAAA

CH₃CH₂CH₂CH₂CH₂CH₂I

Iodine

Nuclear Quadrupole Coupling Constants

in 1-Iodohexane AAAA

Calculation of the iodine nqcc tensor in the AAAA conformer of 1-iodohexane was made on molecular structures obtained by MP2/6-311G(2d,2p) and MP2/6-311G(df,pd) optimization. These calculated nqcc's are compared with the experimental values of Stephens et al. [1] in Table 1. Structure parameters are given in Table 2, rotational constants in Table 3, quartic centrifugal distortion constants in Table 4.

In Table 1, 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. ETA = (X_xx - X_yy)/X_zz. Ø (degrees) is the angle between its subscripted parameters.

RMS is the root mean square difference between calculated and experimental diagonal nqcc's (percent of the average of the magnitudes of the experimental nqcc's). RSD is the residual standard deviation of calibration of the B1LYP/6-311G(df,p) model for calculation of the efg's/nqcc's.


Table 1. ¹²⁷I nqcc's in 1-Iodohexane AAAA (MHz). Calculation was made on the followingstructures: r_opt (1) = MP2/6-311G(2d,2p) optimization, and r_opt (2) = MP2/6-311G(df,pd) optimization.

		Calc. (1)		Calc. (2)		Expt [1]

X_aa	-	1212.5	-	1206.2	-	1197.0(12)
X_bb		306.1		299.8		286.2(18)
X_cc		906.5		906.4		910.8(18)
\|X_ab\|		1115.2		1020.8		1135.40(12)

RMS		14.8 (1.85 %)		9.8 (1.23 %)
RSD		15.2 (1.23 %)		15.2 (1.23 %)

X_xx		896.0		897.1		900.7(14)
X_yy		906.4		906.3		910.8(18)
X_zz	-	1802.4	-	1803.4	-	1811.5(10)
ETA		0.0058		0.0051		0.0056(13)
Ø_z,a		27.88		28.05		28.42
Ø_a,CI		27.16		27.27
Ø_z,CI		0.72		0.78


Table 2. 1-Iodohexane AAAA: r_opt (1) = MP2/6-311G(2d,2p) optimization, and r_opt (2) = MP2/6-311G(df,pd) structure parameters (Å and degrees).


	I C,1,B1 C,2,B2,1,A1 C,3,B3,2,A2,1,D1,0 C,4,B4,3,A3,2,D2,0 C,5,B5,4,A4,3,D3,0 H,2,B6,1,A5,3,D4,0 H,2,B7,1,A6,3,D5,0 H,3,B8,2,A7,1,D6,0 H,3,B9,2,A8,1,D7,0 H,4,B10,3,A9,2,D8,0 H,4,B11,3,A10,2,D9,0 H,5,B12,4,A11,3,D10,0 H,5,B13,4,A12,3,D11,0 H,6,B14,5,A13,4,D12,0 H,6,B15,5,A14,4,D13,0 C,6,B16,5,A15,4,D14,0 H,17,B17,6,A16,5,D15,0 H,17,B18,6,A17,5,D16,0 H,17,B19,6,A18,5,D17,0

	r_opt (1)	r_opt (2)

	B1=2.14397817 B2=1.51453222 B3=1.52738257 B4=1.52567127 B5=1.52511575 B6=1.08433696 B7=1.08433696 B8=1.08958975 B9=1.08958975 B10=1.09203404 B11=1.09203404 B12=1.09210165 B13=1.09210165 B14=1.09075935 B15=1.09075935 B16=1.52564967 B17=1.08841937 B18=1.08725219 B19=1.08841937 A1=112.58863241 A2=111.17895301 A3=112.50942969 A4=113.08929103 A5=105.66160678 A6=105.66160678 A7=109.68977615 A8=109.68977615 A9=109.45200588 A10=109.45200588 A11=109.26197904 A12=109.26197904 A13=109.1157125 A14=109.1157125 A15=112.49526738 A16=110.76682078 A17=111.67459823 A18=110.76682078 D1=180. D2=180. D3=180. D4=-122.28989518 D5=122.28989518 D6=-58.46170943 D7=58.46170943 D8=-58.22905644 D9=58.22905644 D10=-58.0188006 D11=58.0188006 D12=-57.95448937 D13=57.95448937 D14=180. D15=59.71059877 D16=180. D17=-59.71059877	B1=2.13729047 B2=1.5173741 B3=1.52647091 B4=1.5244073 B5=1.52397672 B6=1.08986708 B7=1.08986708 B8=1.09409587 B9=1.09409587 B10=1.09633109 B11=1.09633109 B12=1.09640019 B13=1.09640019 B14=1.09519827 B15=1.09519827 B16=1.52375841 B17=1.09236001 B18=1.09141459 B19=1.09236001 A1=112.50219795 A2=111.2598415 A3=112.6410277 A4=113.17635363 A5=106.01511412 A6=106.01511412 A7=109.54734008 A8=109.54734008 A9=109.36431275 A10=109.36431275 A11=109.150713 A12=109.150713 A13=108.94654732 A14=108.94654732 A15=112.62369884 A16=110.63794731 A17=111.47935792 A18=110.63794731 D1=180. D2=180. D3=180. D4=-122.01691724 D5=122.01691724 D6=-58.59386362 D7=58.59386362 D8=-58.34394083 D9=58.34394083 D10=-58.11934341 D11=58.11934341 D12=-58.01200917 D13=58.01200917 D14=180. D15=59.757271 D16=180. D17=-59.757271


Table 3. 1-Iodohexane AAAA. Rotational Constants (MHz). r_opt (1) = MP2/6-311G(2d,2p), and r_opt (2) = MP2/6-311G(df,pd) optimization.

		r_opt(1)	r_opt(2)	Expt [1]

	A	10521.	10512.	10304.4(16)
	B	295.	296.	294.44727(41)
	C	290.	291.	289.40324(51)


Table 4. 1-Iodohexane AAAA. Quartic Centrifugal Distortion Constants (kHz). Calc = B3LYP/6-311G(d,p).

			Calc		Expt [1]

	D_J		0.00463		0.00475(97)
	D_JK	-	0.863	-	0.75(18)
	D_K		146.
	d_1	-	0.00024
	d_2	-	0.000001

[1] S.L.Stephens, J.A.Signore, D.A.Obenchain, R.K.Bohn, S.E.Novick, and S.A.Cooke, Abstract WJ06, 73rd International Symposium on Molecular Spectroscopy, Champaign-Urbana, Ill 2018.

1-Iodopentane AAA

1-Iodobutane AA

CH₃I

CH₃CH₂I

trans-1-Iodopropane

gauche-1-Iodopropane

Table of Contents

Molecules/Iodine

1_Iodohexane_AAA.html

Last Modified 30 June 2018