Bis(5,5,7,12,12,14-hexa-methyl-1,4,8,11-tetra-azacyclo-tetra-decane-κN)(μ-l-mal-ato-κO,O:O,O)dinickel(II) bis(perchlorate) monohydrate.

In the crystal structure of the title dinuclear compound, Ni(2)(C(4)H(4)O(5))(C(16)H(36)N(4))(2)(2)·H(2)O, the bridg-ing di-car-box-yl-ate dianion O,O'-chelates to two Ni atoms, both of which are also chelated by the N-macrocylic ligand. The Ni atoms exhibit a distorted octa-hedral coordination. N-H⋯O and O-H⋯O hydrogen bonds link the cations and the uncoordinated water mol-ecules into a layer structure; the perchlorate anions occupy the space between adjacent layers, and are only weakly linked to the layers. One of the perchlorate anions is disordered over two sets of sites in a 3:2 ratio.