Di-mu-chloro-bis([2-[N,N-bis(2-aminoethyl)amino-kappa3N]ethylaminium]-copper(II)) bis(naphthalene-1,5-disulfonate) pentahydrate.

The title compound, [Cu2(C6H19N4)2Cl2](C10H6O6S2)2*5H2O, is comprised of discrete [Cu2(tren)2Cl2]2+ dimers [tren is 2-[N,N-bis(2-aminoethyl)amino]ethylaminium] and naphthalene-1,5-disulfonate anions. Two Cl- anions bridge two Cu(II) ions, each of which is also coordinated by two of the primary and the tertiary amino N atoms of the tren ligand, giving each metal atom a distorted square-pyramidal coordination geometry. The cation lies about an inversion centre and the asymmetric unit also has two independent anions lying about inversion centres.