Nuclear Quadrupole Coupling Constants

in 1-Bromoadamantane




Bromine nqcc's in 1-bromoadamantane have been determined by Legon et al. [1].


Calculation of the nqcc's was made here on a structure given by MP2/6-311+G(d,p) optimization with approximate equilibrium CBr (= 1.9642 ) and CH bond lengths (~ re).  Calculated and experimental nqcc's are compared in Table 1.  Structure parameters are shown in Table 2.




Table 1.  Bromine nqcc's in 1-Bromoadamantane (MHz).



Expt. [1]


79Br eQq


81Br eQq




Table 2.  MP2/6-311+G(d,p) C-C bond lengths and CCC angles (bridgehead) in 1-X-adamantane, where X = CN, Cl, Br, and I ( and degrees).  For comparison, in adamantane optimized at the same level of theory, all C-C = 1.5366 and CCC = 109.36o.  The complete structure of 1-bromoadamantane is given here in Z-matrix format.

X = CN   Cl   Br   I

CC (bridgehead) 1.5447 1.5283 1.5293 1.5309
CCC (bridgehead) 109.27 110.07 110.15 110.17
CC (column) 1.5355 1.5383 1.5397 1.5411
CC (base) 1.5360 1.5362 1.5356 1.5353


The rotational constant for the 79Br species calculated on the MP2/6-311+G(d,p) structure is B = 559.80 MHz, the experimental rotational constant is 557.7828(1) MHz [1].



[1] A.C.Legon, D.J.Millen, A.J.Steel, and A.L.Wallwork, J.Mol.Struct. 245,97(1991).


D.Chadwick, A.C.Legon, and D.J.Millen, J.Chem.Soc. A 1116(1968).

1-Fluoroadamantane:  A.C.Legon, J.Tizard, and Z.Kisiel, J.Mol.Struct. 612,83(2002).



1-Chloroadamantane 1-Iodoadamantane 1-Cyanoadamantane

t-Butyl Chloride t-Butyl Bromide t-Butyl Iododine

t-Butyl Cyanide



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Last Modified 19 May 2015