Abstract

(-Benzene-1,2,4,5-tetra-carboxyl-ato- 2 O 1:O 4)bis-[aqua-bis(2,2-methyl-propane-1,3-diamine- 2 N,N')nickel(II)] methanol disolvate tetra-hydrate, [Ni2(C10H2O8)(C5H14N2)4(H2O) 2]·2CH4O·4H2O, (I), is dinuclear, with ele-mental units built up around an inversion centre halving the benzene-1,2,4,5-tetra-carboxyl-ate (btc) anion, which bridges two symmetry-related Ni II cations. The octa-hedral Ni polyhedron is completed by two chelating 2,2-methyl-propane-1,3- diamine (dmpda) groups and a terminal aqua ligand. Two methanol and four water solvent mol-ecules are involved in a number of N - H?O and O - H?O hydrogen bonds which define a strongly bound two-dimensional supra-molecular structure. The structure of catena-poly[[[bis-(2,2-methyl-propane-1,3-diam-ine- 2 N,N')nickel(II)] - pyridine-2,5-dicarboxyl-ato- 3 O 5:N,O 2-[(2,2-methyl-propane-1,3-diamine- 2 N,N')nickel(II)] - pyridine-2,5-dicarboxyl-ato- 3 N,O 2:O 5] octa-hydrate], {[Ni2(C7H3NO4)2(C5H14N2)3]·8H2O} n , (II), is polymeric, forming twisted chains around three independent Ni centres, two of which lie on inversion centres and the third in a general position. There are three chelating dmpda ligands (one disordered over two equally populated positions), which are each attached to a different cation, and two pyridine-2,5-dicarboxyl-ate (pdc) anions, both chelating the Ni centre in general positions through an -O - C - C - N- loop, while acting as bridges to the remaining two centrosymmetric Ni atoms. There are, in addition, eight noncoordinated water mol-ecules in the structure, some of which are disordered. © 2009 International Union of Crystallography.