Diaquabis[mu-(R,R)-tartrato-kappa4O1,O2:O3,O4]dinickel(II) trihydrate

In the crystal structure of the title compound, [Ni(2)(C(4)H(4)O(6))(2)(H(2)O)(2)].3H(2)O, two nickel cations, two tartrate anions and two water molecules form the dimeric complex. Each nickel cation is in a distorted octahedral environment composed of four O atoms of two crystallographically independent tartrate anions, one water molecule and one O atom of a symmetry-equivalent tartrate anion. The asymmetric unit contains three additional water molecules which are connected via hydrogen bonding.