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1995 (1)
1Author    GlennH. Penner3, Baiyi Zhaoa, KennethR. Jeffrey0Requires cookie*
 Abstract    The molecular dynamics of solid (CH3)3NBH3 is investigated by deuterium NMR spectroscopy. Variable temperature lineshape analyses yield activation energies of 27 + 3, 19 + 2, and 12.5 ± 2 kJ/mol for -CH3, -N(CH3)3 and -BH3 rotation, respectively. Analysis of the temperature depen­ dence of the spin-lattice relaxation times, Tt , gives activation energies of 33 + 3, 15 + 1.5, and 14 + 1.5 kJ/mol, respectively. Direct comparison of rotational exchange rates (from lineshape simu­ lations) an of rotational correlation times (from Tx analyses) for -N(CH3)3 and -BH3 rotation indicate that the two motions are correlated in solid (CH3)3NBH3 and together constitute a whole molecule reorientation about the N-B bond. This is supported by an internal rotational barrier of 18.0 kJ/mol for-BH3 rotation, obtained from ab initio molecular orbital calculations at the MP2/6-31G* level. 
  Reference    Z. Naturforsch. 50a, 81—89 (1995); received September 22 1994 
  Published    1995 
  Keywords    NMR spectroscopy, Molecular dynamics, NMR relaxation 
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 TEI-XML for    default:Reihe_A/50/ZNA-1995-50a-0081.pdf 
 Identifier    ZNA-1995-50a-0081 
 Volume    50