Bis(2,2':6',2''-terpyridine)-ruthenium(II) bis-(perchlorate) hemihydrate.

The asymmetric unit of the title compound, [Ru(C(15)H(11)N(3))(2)](ClO(4))(2)·0.5H(2)O, contains one ruthenium-terpiridine complex cation, two perchlorate anions and one half-mol-ecule of water. Face-to-face and face-to-edge π-stacking inter-actions between terpyridine units [centroid-centroid distances = 3.793 (2) and 3.801 (2)  Å] stabilize the crystal lattice The partially occupied water mol-ecule inter-acts with two perchlorate ions via O-H⋯O hydrogen bonds. In the crystal lattice, the complex cations, perchlorate ion-water pairs and the second perchlorate anions are arranged into columns along b direction.