Supramolecular Assemblies of Mononuclear and Polymeric Nickel(II) Glutarato Complexes via π‐π Stacking Interactions and Hydrogen Bonds: [Ni(H 2 O) 3 (phen)(C 5 H 6 O 4 )] · H 2 O and [Ni(H 2 O) 2 (phen)(C 5 H 6 O 4 )]

Syntheses of the sky blue complex compounds [Ni(H 2 O) 3 (phen)(C 5 H 6 O 4 )] · H 2 O ( 1 ) and [Ni(H 2 O) 2 (phen)(C 5 H 6 O 4 )] ( 2 ) were carried out by the reactions of 1,10‐phenanthroline monohydrate, glutaric acid, NiSO 4  · 6 H 2 O and Na 2 CO 3 in CH 3 OH/H 2 O at pH = 6.9 and 7.5, respectively. The crystal structure of 1 ( P  1 (no. 2), a  = 14.289 Å, b  = 15.182 Å, c  = 15.913 Å, α = 67.108°, β = 87.27°, γ = 68.216°, V  = 2934.2 Å 3 , Z  = 2) consists of hydrogen bonded [Ni(H 2 O) 3 ‐ (phen)(C 5 H 6 O 4 )] 2 dimers and H 2 O 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 Å; d(Ni–O) = 2.064–2.079 Å). Through the π‐π stacking interactions and intermolecular hydrogen bonds, the dimers are assembled to form 2 D layers parallel to (0 1 1). The crystal structure of 2 ( P 2 1 / n (no. 14), a  = 7.574 Å, b  = 11.938 Å, c  = 18.817 Å, β = 98.48°, V  = 1682.8 Å 3 , Z  = 4) contains $^1_\infty$ [Ni(H 2 O) 2 (phen)(C 5 H 6 O 4 ) 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 Å and d(Ni–O) = 2.059–2.087 Å. The supramolecular chains are assembled into a 3 D network by π‐π stacking interactions and interchain hydrogen bonds. A TG/DTA of 2 shows two endothermic effects at 132 °C and 390 °C corresponding to the complete dehydration and the lost of phen.