
%0 Journal Article
%A Field, LD 
%A Skelton, BW 
%A Sternhell, S 
%A White, AH 
%T Structual Studies of Some 2,6(2&#8242;,6&#8242;)-Halogen-Substituted Biphenyl Derivatives
%J Australian Journal of Chemistry
%D 1985/03/01
%V 38
%N 3
%P 391-399
%K 
%R https://doi.org/10.1071/CH9850391
%U https://www.publish.csiro.au/paper/CH9850391 
%X Single-crystal X-ray structure determinations have been carried out at 295 K on a number of biphenyl derivatives substituted with chlorine or bromine in the 2- and 6-positions in order to ascertain the effect of substitution on the torsion angle about the central bond. 2,2&#8242;,6,6&#8242;- Tetrachlorobiphenyl, (1), is orthorhombic, P nca, a 12.35(1), b 10.521(7), c 9.390(8)&#506;, Z 4; the structure was refined to a residual of R 0.040 for No 528 independent 'observed' reflections. The interplanar dihedral angle, &#952;, is 81.7&#176;. 4&#8242;-Bromo-2,4,6-trichlorobiphenyl, (2), is monoclinic, C2/c, a 19.27(1), b 7.940(2), c 33.315(8)&#506;, &#946; 90.93(6)&#176;, Z 16; R 0.036 for No 1795 with &#952; 84.3 and 80.6&#176; for the two independent molecules. 2,2&#8242;,4,4&#8242;,6,6&#8242;-Hexabromobiphenyl, (3), is orthorhombic, P nca, a 14.48(1), b 12.71(1), c 8.534(7)&#506;; R 0.044 for No 693 with &#952; 83.0&#176;. 2,4,4&#8242;,6-Tetrabromobiphenyl, (4), is triclinic, P&#299;, with a 8.14(1), b 10.74(2), c 35.42(4)&#506;, &#945; 87.87(10), &#946; 79.39(10), &#947; 63.55(10)&#176;, Z 8; R 0.049 for No 3962, with &#952; 89.8, 80.7 86.9, 83.6&#176;, for the four independent molecules. Steric interactions between the substituents ortho to the central inter-ring bond are not the sole determinant of the geometry of these compounds in the solid state. The pairs (1) and (3), and (2) and (4), are pseudo-isostructural in each case. 
