Syntheses, Crystal Structures, and Thermal Behavior of Co(phen)(HL) 2 and [Co 2 (phen) 2 (H 2 O) 4 L 2 ]·H 2 O with H 2 L = Pimelic Acid

Two Co II complexes, Co(phen)(HL) 2 ( 1 ) and [Co 2 (phen) 2 (H 2 O) 4 L 2 ]·H 2 O ( 2 ) (H 2 L = HOOC‐(CH 2 ) 5 ‐COOH), were synthesized and structurally characterized on the basis of single crystal X‐ray diffraction data. In complex 1 the Co atoms are tetrahedrally coordinated by two N atoms of one phen ligand and two O atoms of different hydrogenpimelato ligands. Through π—π stacking interactions between carboxyl group and phen ligand, the complex molecules are assembled into 1D columnar chains, which are connected by intermolecular hydrogen bonds. Complex 2 consists of the centrosymmetric dinuclear [Co 2 (phen) 2 (H 2 O) 4 L 2 ] molecules and hydrogen bonded H 2 O molecules. The Co atoms are each octahedrally surrounded by two N atoms of one phen ligand and four O atoms from two bis‐monodentate pimelato ligands and two H 2 O molecules at the trans positions. The results about thermal analyses, which were performed in flowing N 2 atmosphere, on both complexes were discussed. Crystal data: ( 1 ) C 2/ c (no. 15), a = 13.491(1)Å, b = 9.828(1)Å, c = 19.392(2)Å, β = 100.648(1)°, U = 2526.9(4)Å 3 , Z = 4; ( 2 ) P 1 (no. 2), a = 11.558(1)Å, b = 11.947(3)Å, c = 15.211(1)Å, α = 86.17(1)°, β = 75.55(1)°, γ = 69.95(1)°, U = 1910.3(3)Å 3 , Z = 2.