Bathocuproine is an organic compound with the formula (C6H5)2(CH3)2C12H4N2. It is related to 1,10-phenanthroline by the placement of two methyl groups and two phenyl groups in the 2,9 and 4,7 positions, respectively. Like 1,10-phenanthroline, bathocuproine is a bidentate chelating ligand. The two methyl groups flank the nitrogen centers, such that bathocuproine is a bulky ligand. It forms a monomeric 1:1 complex with nickel(II) chloride, whereas the less bulky parent phenanthroline forms a 2:1 complex.