SiFBr3
		Bromine
	Nuclear Quadrupole Coupling Constants
		in Fluorotribromosilane
	The microwave spectrum of fluorotribromosilane was observed by Mitzlaff et al. [1], which authors derived an ro molecular structure.
	Calculation was made here of the bromine nqcc's on the this structure.  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 Br 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.  Bromine nqcc's in SiFBr3 (MHz).  Calculation was made on the ro structure [1].     Calc. Expt.   79Br Xuu - 134.35 Xvv 314.57 Xww - 180.22 Xuv - 138.72   Xxx - 173.76 Xyy - 180.22 Xzz 353.98 ETA 0.0182 Øz,u 105.9 Øu,SiBr 107.5 Øz,SiBr     1.6
	Table 2.  Fluorotribromosilane.  Molecular structure parameters [1] (Å and degrees).     ro SiF 1.5607 SiBr 2.1706   BrSiBr 111.36
	Table 3.  Fluorotribromosilane.  Heavy atom coordinates, ro  u (Å)  v (Å)  w (Å) Si 0.4404 0 0 F 2.0011 0 0 Br - 0.2126 2.0700 0 Br - 0.2126 - 1.0350 ± 1.7927
	[1] M.Mitzlaff, R.Holm, and H.Hartmann. Z.Naturforsch. 23a,1819(1968).
	SiHBr3		CH3SiBr3		CHBr3		CH3CBr3
	Table of Contents
	Molecules/Bromine
						SiFBr3.html
						Last Modified 25 Jan 2017