STRUCTURE OF 1',1'''-DIMETHYL-1,1''-TETRAMETHYLENEDI(4,4'-BIPYRIDINIUM) TETRAPERCHLORATE

C26H30N4(4)+.4ClO4-, M(r) = 796.36, orthorhombic, Pbca, a = 9.791 (2), b = 15.908 (4), c = 21.288 (5) angstrom, V = 3315.7 angstrom 3, Z = 4, D(x) = 1.595 g cm-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 4.399 cm-1, F(000) = 1640, T = 295 (1) K, R = 0.052 for 2072 unique observed reflections with I > 3.0-sigma(I) and 226 parameters. 1',1'''-Dimethyl-1,1''-tetramethylenedi(4,4'-bipyridinium) belongs to the viologen compounds, which undergo reversible one-electron reduction to colored radical cations. This property is utilized in the mediation of electron-transfer processes. The structure determination was undertaken to establish the stereochemistry of the compound. The dihedral angle between the least-squares planes of the two pyridine rings is 3.3-degrees, indicating that the two rings are essentially coplanar. One half of the molecule is related to the other half by a crystallographic inversion center at the middle of the butanediyl group in the unit cell. The anions display an approximate tetrahedral geometry.