Crystal structure of a symmetrical heterotrinuclear NiII-MnII-NiII complex: bis[(N,N'-dimethylformamide) (mu-acetato) [mu-N,N'-bis(salicylidene)-2-hydroxy-1,3-propanediamine]nickel(II)]manganese(II).

derivative3–6 (1) have been reported to have a greater tendency to yield polynuclear complexes. This communication presents the X-ray structure of the Ni–Mn–Ni complex (2) prepared using ligand 1 (Fig. 1). The title complex was prepared in two steps. Step 1: After the ligand (0.01 mol, 2.98 g) was dissolved in hot EtOH (50 mL), a solution of NiCl2·6H2O (0.01 mol, 2.37 g) in hot water (30 mL) and ammonia (10 mL) was then added. The resulting solution was thoroughly mixed and set aside for 2 h. The precipitated crystals were filtered and dried at 363 K. Step 2: Filtered crystals were dissolved in hot DMF and mixed with a hot MeOH (20 mL) solution of Mn(AcO)2·4H2O (0.0005 mol, 0.123 g). The resulting solution was set aside for 24 h. The precipitated crystals were filtered, dried in air and used for Xray data collection with graphite-monochromatized Mo Kα (λ = 0.71093 Å) radiation. The crystal and experimental data are presented in Table 1 and an ORTEP7 plot of the titled complex is shown in Fig. 2. Table 2 gives the final atomic coordinates, while the bond distances and angles are given in Table 3. Each Ni atom is coordinated by 4 oxygen and 2 nitrogen atoms. The Mn atom is located on a center of inversion, and is coordinated by 6 oxygen atoms. The distance Ni–Mn is 3.1299(6)Å and the Ni–Mn–Ni bond angle is 180 ̊. The methylene-bonded OH group was expected to form intermolecular interactions, but instead formed intramolecular H-bonding to the O(1) atom of the coordinated dimethylformamide group, such that the O6–H6···O1: O6–H6 distance is 1.11(4)Å; the H6···O1 distance is 1.87(4)Å and the O6–H6···O1 angle is 175(4) ̊. 493 ANALYTICAL SCIENCES APRIL 2002, VOL. 18 2002 © The Japan Society for Analytical Chemistry