Tetraallyl (2,2 '-bipyridyl)-rac-3,3,7,7-tetramethyl-trans-5-palladatricyclo-[4.1.0.0(2,4)]heptane-1,2,4,6-tetracarboxylate above and below the phase-transition temperature of 194 K

The crystal structure of the title compound, (2,2'-bipyridyl- kappa(2)N,N') (tetraallyl 3,3,3',3'-tetramethyl-1,1'-bicyclopropane-1,1',2,2' -tetracarbo xylato-kappa(2) C-2,C-2')palladium(II), [Pd(C26H32O8)(C10H8N2)], is disorde red above 194 K. A doubling of the unit cell is observed on cooling. The st ructure at 143 K contains two ordered molecules related by a pseudo-transla tion vector of approximately (0.44,0.00,0.50) or a pseudoinversion center a t approximately (0.22,0.00,0.25). Weak intermolecular C-H ... O interaction s are enhanced in the low-temperature structure.