(CH3)3CBr
		Bromine
	Nuclear Quadrupole Coupling Constants
		in t-Butyl Bromide
	Calculation of the Br nqcc's in t-butyl bromide was made on the experimental rs/ro structure [2,4], on an ropt structure given by PBE1PBE/6-31G(3d,3p) optimization, and on an ~re structure given by MP2/aug-cc-pVTZ optimization with empirically corrected C-C and CBr bond lengths..  These are compared with the experimental nqcc's [1-3] in Table 1.  Structure parameters are given in Table 2.
	Table 1. Bromine nqcc's in (CH3)3CBr (MHz).  Calculations were made on the rs/ro,  ropt, and ~re structures.     Calc. Expt.     79Br Xzz 521.94   rs/ro 511.9797(19) [1] 517.96   ropt 511.89 [2] 517.16   ~re  511.987(4) [3]   81Br Xzz 436.06   rs/ro 427.7087(17) [1] 432.74    ropt 427.71 [2] 432.07    ~re  427.708(3) [3]
	The difference between calculated (rs/ro) and experimental [1] 79Br nqcc's is 9.96 MHz (1.9 %).  For 81Br, the difference is 8.35 MHz (2.0 %).
	The difference between calculated (ropt) and experimental [1] 79Br nqcc's is 5.98 MHz (1.2 %).  For 81Br, the difference is 5.03 MHz (1.2 %).
	The difference between calculated (~re) and experimental [1] 79Br nqcc's is 5.18 MHz (1.0 %).  For 81Br, the difference is 4.36 MHz (1.0 %).
	Table 2.  t-Butyl Bromide.  Heavy atom structure parameters, ro [2] / rs [4] (CH = 11.097 Å and CCH = 109.46 Å assumed), ropt, and ~re (Å and degrees).  Complete ropt and ~re structures are given here in Z-matrix format.       rs/ro   ropt   ~re    CBr 1.975(2) 1.9727 1.9700 CC 1.533(2) 1.5185 1.5156 BrCC 107.7(5) 107.09 107.40
	[1] Z.Kisiel, E.Białkowska-Jaworska, O.Desyatnyk, B.A.Pietrewicz, and L.Pszcółkowski, J.Mol.Spectrosc. 208,113(2001).
	[2] J.H.Carpenter, C.D.Gowland, D.C.Read, and J.G.Smith, J.Mol. Spectrosc. 159,192(1993).
	[3] H.Harder, W.Stahl, and H.Dreizler, Z.Naturforsch. 45a,807(1990).
	[4] A.C.Legon, D.J.Millen, and A.Samsam-Baktiari, J.Mol.Struct. 52,71(1979).
	S.Kassi, D.Petitprez, and G.Wlodarczak, J.Mol.Struct. 517-518,375(2000).  79Br and 81Br nqcc's in 13C species, namely 512.0653(19) and 427.7772(18) MHz respectively; and rs(CBr) = 1.97394(6) Å.
	CH3Br		SiF3Br		GeH3Br		SiH3Br
	(CH3)3CCl		CH3Cl		CF3Cl		(CH3)3CI
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	Molecules/Bromine
						CH33CBr.html
						Last Modified 18 Aug 2009