SiHCl3
		Chlorine
	Nuclear Quadrupole Coupling Constants
		in Trichlorosilane
	Mitzlaff, et al. in 1967 [1], Takeo and Matsumura in 1977 [2], and Carpenter and Smith in 1987 [3] each determined the component of the nqcc tensor along the threefold symmetry axis.  Substitution molecular structures are reported in [1] and [2].  An ab initio equilibrium structure was derived by He et al. [4].
	Chlorine nqcc's in trichlorosilane were calculated here on the substitution structures of [1] and [2], and on the equilibrium structure [4].  The results are given in Table 1.  Structure parameters are given in Table 2, atomic coordinates in Table 3.
	Coordinate Systems
	Xuu is the component of the nqcc tensor along the threefold symmetry axis.  Corresponding to the atomic coordinates given below in Table 3, Xvv and Xww are the components along the v- and w- axes for the Cl atom in the uv-plane.
	Subscripts x,y,z refer to the principal axes of the nqcc tensor.  The nqcc y-axis is chosen coincident with the w-axis.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.
	Table 1.  35Cl nqcc's in SiHCl3 (MHz).  Calculation was made on the substitution structures of Mitzlaff, et al. [1] and Takeo and Matsumura [2], and on the equilibrium structure of He et al. [4].     Calc. [1] Calc. [2] Calc. [4] Expt. [3]   Xuu 15.13 13.83 14.25 13.66(15) Xvv - 34.51 - 33.57 - 34.36 Xww 19.38 19.74 20.11 Xuv 15.63 17.86 18.08   Xxx 19.64 19.80 20.24 Xyy 19.38 19.74 20.11 Xzz - 39.02 - 39.55 - 40.35 ETA - 0.007 - 0.002 - 0.003 Øz,u 73.90 71.50 71.68 Øu,SiCl 71.68 70.5 70.54 Øz,SiCl   2.22   1.0   1.13
	The pyramid formed by the z-principal axes of the three Cl nqcc tensors is somewhat 'flatter' than the molecular pyramid.  This is typical of the pyramidal trichlorides.
	Table 2.  Trichlorosilane.  Molecular structure parameters (Å and degrees).   rs [1] rs [2] re [4] SiCl 2.0118(9) 2.020 2.0306 SiH 1.4655(2) 1.464 1.4613 HSiCl 108.32(25) 109.5 109.4570
	Table 3.  Trichlorosilane.  Atomic coordinates,  rs [2].  u (Å)  v (Å)  w (Å) Cl - 0.1570 1.9041 0 Cl - 0.1570 - 0.9521 ± 1.6490 Si 0.5173 0 0 H 1.9813 0 0
	[1] M.Mitzlaff, R.Holm, and H.Hartmann, Z.Naturforsch. 22a,1415(1967).
	[2] H.Takeo and C.Matsumura, Bull. Chem. Soc. Japan, 50,1633(1977).
	[3] J.H.Carpenter and J.G.Smith, J.Mol. Spectrosc. 121,270(1987).
	[4] S.-G.He, H.Lin, H.Bürger, W.Thiel, Y.Ding, and Q.-S.Zhu, J.Chem.Phys. 116,105(2002).
	"An ab initio Study of the Molecular Electric-field Gradients of the Chlorosilanes" H.U.Suter, D.M.Maric, and P.F.Meier,Z.Naturforsch. 51a,41(1996).
	B.P.Prascher, R.M.Lucente-Schultz, and A.K.Wilson, Chem.Phys. 359,1(2009).  CCSD(T) optimization of the molecular structure.
	NCl3		SiH3Cl		SiH2Cl2		SiF3Cl
	PCl3		SPCl3		OPCl3		CH3CCl3
	AsCl3		CHCl3		CFCl3
	Table of Contents
	Molecules/Chlorine
						SiHCl3.html
						Last Modified 23 Jan 2008