Supramolecular assemblies of mononuclear and polymeric nickel(II) glutarato complexes via π-π stacking interactions and hydrogen bonds:: [Ni(H2O)3(phen) (C5H6O4) • H2O and [Ni(H2O)2(phen)(C5H6O4)]

Syntheses of the sky blue complex compounds [Ni(H2O)(3)(phen)(C5H6O4)].H2O (1) and [Ni(H2O)(2)(phen)-(C5H6O4)] (2) were carried out by the reactions of l,l0-phenanthroline monohydrate, glutaric acid, NiSO4. 6H(2)O and Na2CO3 in CH3OH/H2O at pH = 6.9 and 7.5, respectively. The crystal structure of 1 (P (1) over bar (no. 2), a = 14.289 Angstrom, b = 15.182 Angstrom. c =15.913 Angstrom. alpha = 67.108 degrees, beta = 87.27 degrees, gamma = 68.216 degrees, V = 2934.2 Angstrom (3), Z = 2) consists of hydrogen bonded [Ni(H2O)(3)- (phen)(C5H6O4)](2) dimers and H2O molecules. The Ni atoms are octahedrally coordinated by two N atoms of one phen ligand, three water O atoms and one carboxyl O atom from one monodentate glutarato ligand (d(Ni-N) = 2.086, 2.090 Angstrom; d(Ni-O)= 2.064-2.079 Angstrom). Through the pi-pi stacking interactions and intermolecular hydrogen bonds, the dimers are assembled to form 2D layers parallel to (0 (1) over bar1). The crystal structure of 2 (P2(l)/n (no.14), alpha = 7.574 Angstrom, b = 11.938 Angstrom, c = 18.817 Angstrom, beta = 98.48 degrees, V = 1682.8 Angstrom (3), Z = 4) contains (1)(infinity) [Ni(H2O)(2)(phen)(C5H6O4)(2/2)] supramolecular chains extending along [010]. The Ni atoms are octahedrally coordinated by two N atoms of one phen ligand, two water O atoms and two carboxyl O atoms from different bis-monodentate glutarato ligands with d(Ni-N)= 2.082, 2.105 Angstrom and d(Ni-O)= 2.059-2.087 Angstrom. The supramolecular chains are assembled into a 3D network by pi-pi stacking interactions and interchain hydrogen bonds. A TG/DTA of 2 shows two endothermic effects at 132 degreesC and 390 degreesC corresponding to the complete dehydration and the lost of phen.