
%0 Journal Article
%A Fuller, DJ 
%A Kepert, DL 
%A Skelton, BW 
%A White, AH 
%T Structure, Stereochemistry and Novel 'Hydrogen Bonding' in Two Bipyridinium Salts of the B<sub>10</sub>H<sub>10</sub><sup>2-</sup> Anion
%J Australian Journal of Chemistry
%D 1987/12/01
%V 40
%N 12
%P 2097-2105
%K 
%R https://doi.org/10.1071/CH9872097
%U https://www.publish.csiro.au/paper/CH9872097 
%X Crystal structure determinations of (LH)2(B10H10), (1), and (LH2)(B10H10), (2), L = 2,2'- bipyridine , have been carried out by single-crystal X-ray diffraction methods at 295 K, being refined by full-matrix least squares to residuals of 0.041, 0.047 for 1758, 1771 'observed' independent reflections respectively. Crystals of (1) are monoclinic, P21/n, a 12.040(7), b 17.71(1), c 11.142(4) Å, &#946; 101.78(4)º, Z 4. Crystals of (2) are monoclinic, P21/c, a 9.937(4), b 10.837(3), c 14.856(5) Å, &#946; 109 2l(3)º, Z 4. The colour of the compounds is accounted for by charge-transfer interactions of a novel type, namely between the positively charged cationic acid hydrogen atoms and the negatively charged non-apical hydrogen atoms of the anion. In yellow (1), these distances are 2.26(5) Å, while in red (2), they are much shorter, being 1.89(4), 1.97(3) Å. 
