Synthesis and crystal structure of bis-[ trans -di-aqua-(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ 4 N 1 , N 4 , N 8 , N 11 )nickel(II)] trans -(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ 4 N 1 , N 4 , N 8 , N 11 )bis-[4,4',4''-(1,3,5-tri-methyl-benzene-2,4,6-tri-yl)tris-(hydrogen phenyl-phospho-nato-κ O )]nickel(II) deca-hydrate.

The components of the title compound, [Ni(C 10 H 24 N 4 )(H 2 O) 2 ] 2 [Ni(C 10 H 24 N 4 )(C 27 H 24 O 9 P 3 ) 2 ]·10H 2 O are two centrosymmetric [Ni(C 10 H 24 N 4 )(H 2 O) 2 ] 2+ dications, a centrosymmetric [Ni(C 10 H 24 N 4 )(C 27 H 24 O 9 P 3 ) 2 ] 4- tetra-anion and five crystallographically unique water mol-ecules of crystallization. All of the nickel ions are coordinated by the four secondary N atoms of the macrocyclic cyclam ligands, which adopt the most energetically stable trans -III conformation, and the mutually trans O atoms of either water mol-ecules in the cations or the phospho-nate groups in the anion in a tetra-gonally distorted NiN 4 O 2 octa-hedral coordination geometry. Strong O-H⋯O hydrogen bonds between the protonated and the non-protonated phospho-nate O atoms of neighboring anions result in the formation of layers oriented parallel to the bc plane, which are linked into a three-dimensional network by virtue of numerous N-H⋯O and O-H⋯O hydrogen bonds arising from the sec -NH groups of the macrocycles, phospho-nate O atoms and coordinated and non-coordinated water mol-ecules.