3,3'-DIMETHYL-4,4'-BIPYRIDINE AND 5,5'-DIMETHYL-4,4'-BIPYRIMIDINE

In both title compounds, the aromatic rings adopt a staggered conformation as a result of steric repulsions. In the bipyridine derivative, the closest contacts between methyl H atoms and pyridyl H atoms are H(31)...H(172) [IUPAC pyridine C5 H atom to C3' methyl group; 2.83 (6) angstrom] and H(71)...H(131) [2.84 (5) angstrom] leading to an angle between the pyridyl least-squares planes of 81.1-degrees. In the bipyrimidine compound, the contacts are between N(3) and methyl H(71) [2.84 (3) angstrom] and N(3) and methyl H(72) (2.77 (3) angstrom] with an angle between the pyrimidyl planes of 46.0-degrees.