The Use of Liquid–Liquid Interface (Biphasic) for the Preparation of Benzenetricarboxylate Complexes of Cobalt and Nickel

New metal–organic frameworks (MOFs) [Ni(C 12 N 2 H 10 )(H 2 O)][C 6 H 3 (COO) 2 (COOH)] ( I ), [Co 2 (H 2 O) 6 ][C 6 H 3 (COO) 3 ] 2 · (C 4 N 2 H 12 )(H 2 O) 2 ( II ), [Ni 2 (H 2 O) 6 ][C 6 H 3 (COO) 3 ] 2 · (C 4 N 2 H 12 )(H 2 O) 2 ( III ), [Ni(C 13 N 2 H 14 )(H 2 O)][C 6 H 3 (COO) 2 (COOH)] ( IV ), [Ni 3 (H 2 O) 8 ][C 6 H 3 (COO) 3 ] ( V ) and [Co(C 4 N 2 H 4 )(H 2 O)][C 6 H 3 (COO) 3 ] ( VI ) {C 6 H 3 (COOH) 3 = trimesic acid, C 12 N 2 H 10 = 1,10‐phenanthroline, C 4 N 2 H 12 = piperazine dication, C 13 N 2 H 14 = 1,3‐bis(4‐pyridyl)propane and C 4 N 2 H 4 = pyrazine} have been synthesized by using an interface between two immiscible solvents, water and cyclohexanol. The compounds are constructed from the connectivity between the octahedral M 2+ (M = Ni, Co) ions coordinated by oxygen atoms of carboxylate groups and water molecules and/or by nitrogen atoms of the ligand amines and the carboxylate units to form a variety of structures of different dimensionality. Strong hydrogen bonds of the type O–H ··· O are present in all the compounds, which give rise to supramolecularly organized higher‐dimensional structures. In some cases π ··· π interactions are also observed. Magnetic studies indicate weak ferromagnetic interactions in I , IV and V and weak antiferromagnetic interactions in the other compounds ( II , III and VI ). All the compounds have been characterized by a variety of techniques.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)