ClCH2CH2PH2
		Chlorine
	Nuclear Quadrupole Coupling Constants
	in (2-Chloroethyl)phosphine
	(2-Chloroethyl)phosphine has been investigated by microwave spectroscopy by Møllendal et al. [1].  The spectra of two rotameric forms, denoted I and II in the following figure, have been observed.  Hyperfine structure due to nuclear quadrupole coupling, however, was not resolved.
		Rotamer I    Cs				Rotamer II    C1
	Calculation of the chlorine nqcc tensors was made here on a molecular structure given by MP2/aug-cc-pVTZ(G03) optimization, and on this same structure but with approximate equilibrium C-C and CCl bond lengths.  The former is herein referred to as ropt, the latter as ~re.
	These calculated nqcc tensors are given in Tables 1 and 2 for rotamer I, and in Tables 3 and 4 for rotamer II.  Structure parameters are given in Table 5, rotational constants in Table 6.
	In Tables 1 - 4, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  Ø (degrees) is the angle between its subscriped axes.  ETA = (Xxx - Xyy)/Xzz.
	RSD is the calibration residual standard deviation of the B1LYP/TZV(3df,2p) model for calculation of the chlorine nqcc's, which may be taken as estimate of the uncertainty inherent in the model for calculation of the nqcc's.
	Table 1.  35Cl nqcc's in ClCH2CH2PH2 Rotamer I (MHz).  Calculation was made on the ropt and ~re structures.     35Cl Calc/ ropt Calc/ ~re Expt.     Xaa - 57.20 - 57.11 Xbb 21.27 21.24 Xcc 35.92 35.87 |Xab| 35.22 35.18   RSD 0.49 (1.1 %) 0.49 (1.1 %)   Xxx 34.76 34.71 Xyy 35.92 35.87 Xzz - 70.69 - 70.59 ETA 0.016 0.016 Øz,a 20.96 20.96 Øa,CCl 20.31 20.31 Øz,CCl   0.65   0.65
	Table 2.  37Cl nqcc's in ClCH2CH2PH2 Rotamer I (MHz).  Calculation was made on the ropt and ~re structures.     Calc/ ropt Calc/ ~re Expt.     Xaa - 45.12 - 45.05 Xbb 16.80 16.78 Xcc 28.31 28.27 |Xab| 27.72 27.68   RSD 0.49 (1.1 %) 0.49 (1.1 %)   Xxx 27.40 27.36 Xyy 28.31 28.27 Xzz - 55.71 - 55.63 ETA 0.016 0.016 Øz,a 20.92 20.92 Øa,CCl 20.27 20.27 Øz,CCl   0.65   0.65
	Table 3.  35Cl nqcc's in ClCH2CH2PH2 Rotamer II (MHz).  Calculation was made on the ropt and ~re structures.     Calc/ ropt Calc/ ~re Expt.     Xaa - 58.41 - 58.31 Xbb 22.06 22.02 Xcc 36.35 36.29 Xab 35.37 35.32 Xac   0.39   0.39 Xbc - 0.18 - 0.18   RSD 0.49 (1.1 %) 0.49 (1.1 %)   Xxx 35.40 35.34 Xyy 36.35 36.29 Xzz - 71.75 - 71.64 ETA 0.013 0.013 Øz,CCl   0.75   0.76
	Table 4.  37Cl nqcc's in ClCH2CH2PH2 Rotamer II (MHz).  Calculation was made on the ropt and ~re structures.     Calc/ ropt Calc/ ~re Expt.     Xaa - 46.07 - 46.00 Xbb 17.42 17.39 Xcc 28.65 28.60 Xab 27.83 27.80 Xac   0.30   0.30 Xbc - 0.14 - 0.14   RSD 0.49 (1.1 %) 0.49 (1.1 %)   Xxx 27.90 27.85 Xyy 28.65 28.60 Xzz - 56.55 - 56.46 ETA 0.013 0.013 Øz,CCl   0.75   0.76
	Table 5. (2-Chloroethyl)phosphine.  Heavy atom structure parameters, ropt and ~ re (Å and degrees).   Complete structures are given here in Z-matrix format.   Rotamer I Rotamer II   ropt   ~ re   ropt   ~ re ClC 1.7966 1.7933 1.7907 1.7875 CC 1.5098 1.5082 1.5132 1.5115 CP 1.8620 1.8694 ClCC 111.13 110.95 CCP 113.74 111.71 ClCCP 180. 177.75
	Table 6.  35ClCH2CH2PH2  Rotational Constants (MHz), ropt and ~ re.    Rotamer I   ropt   ~ re Expt [1] A 24440.22 24465.65 24287(16) B   1451.93   1454.59 1445.8842(23) C   1410.88   1413.48 1404.8867(25)   Rotamer II   ropt   ~ re Expt [1] A 24648.62 24675.71 24547(17) B   1461.71   1464.44 1456.0328(43) C   1418.43   1421.08 1412.9167(54)
	[1] H.Møllendal, A.Konovalov, and J.-C.Guillemin, J.Phys.Chem. A, 113, 12904(2009).
	Calculation of Cl and N Nuclear Quadrupole Coupling Constants on Approximate Equilibrium Molecular Structures:  F, Cl, CN - Ethanes.
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	Molecules/Chlorine
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						Last Modified 16 Nov 2009