
%0 Journal Article
%A Phillip, IG 
%A Steel, PJ 
%T X-Ray Crystal Structures of 2,2'-Bis(pyrazol-1-yl)-4,4'-bipyridine and a Tetramethyl Derivative; New Bis-bidentate Binucleating Ligands
%J Australian Journal of Chemistry
%D 1995/09/01
%V 48
%N 9
%P 1617-1624
%K 
%R https://doi.org/10.1071/CH9951617
%U https://www.publish.csiro.au/paper/CH9951617 
%X X-Ray crystal structures of 2,2&#176;-bis(pyrazol-1-yl)-4,4&#176;-bipyridine (3) and 2,2&#176;-bis(3,5-dimethyl-pyrazol-1-yl)-4,4&#176;-bipyridine (4) have been determined at 130 K. Crystals of (3) are triclinic, P&#299; , a 8.061(1), b 9.024(1), c 10.680(1)&#506;, &#945; 102.032(8), &#946; 107.931(6), &#947; 107.355(7)&#176;, Z = 2; the structure was refined to a conventional R(I > 2&#963;(I)) = 0.0273. Crystals of (4) are orthorhombic, P 212121, a 7.077(2), b 13.906(4), c 16.697(5) &#506;, Z = 4; the structure was refined to a conventional R(I > 2&#963;(I)) = 0.0386. In both molecules there is significant (33±1&#176;) twisting about the central pyridine-pyridine bond. The pyrazole rings of (3) are approximately coplanar (6±2&#176;) with their attached pyridine rings, while in (4) the methyl groups induce slightly greater deviations from coplanarity (15±3&#176;). Factors which influence the solid-state conformations and molecular packing of these molecules are discussed. 
