(Salicylato)[tris(1-methyl-1H-benzimidazol-2-ylmethyl)amine]copper(II) perchlorate dimethylformamide disolvate

In the title complex, [Cu(C7H5O3)(C27H27N7)]ClO4·2C3H7NO, the CuII ion is five-coordinated by four N atoms from the tris(1-methyl-1H-benzimidazol-2-ylmethyl)amine ligand and an O atom of the monodentate salicylate ligand. The N4O donor set defines a coordination geometry intermediate between square-pyramidal and trigonal–bipyramidal. The crystal structure is stabilized by O—H⋯O interactions. The atoms of the aromatic ring of the salicylate ligand are disordered over two sites of equal occupancy. In addition, one of the dimethylformamide solvent molecules is partially disordered over two positions, of approximately equal occupancy.

In the title complex, [Cu(C 7 H 5 O 3 )(C 27 H 27 N 7 )]ClO 4 Á2C 3 H 7 NO, the Cu II ion is five-coordinated by four N atoms from the tris(1-methyl-1H-benzimidazol-2-ylmethyl)amine ligand and an O atom of the monodentate salicylate ligand. The N 4 O donor set defines a coordination geometry intermediate between square-pyramidal and trigonal-bipyramidal. The crystal structure is stabilized by O-HÁ Á ÁO interactions. The atoms of the aromatic ring of the salicylate ligand are disordered over two sites of equal occupancy. In addition, one of the dimethylformamide solvent molecules is partially disordered over two positions, of approximately equal occupancy.
The Cu atom is five-coordinate within a N 4 O ligand set. The Mentb ligand functions as a tetradentate N-donor, and an O atom of a monodentate salicylate anion completes the coordination environment. The coordination environment of the Cu II centre has an intermediate coordination geometry as seen in the value of τ = 0.45, cf. τ = 0 for an ideal square pyramid and τ = 1 for an ideal trigonal bipyramid (Addison et al., 1984). The Cu···O2 distance of 2.960 (2) Å indicates that the O2 atom is non-coordinating. The distances and angles in Mentb and salicylate are as expected (Allen et al., 1987). O-H···O Hydrogen-bonding interactions play an important role in the crystal packing (Table 1). The atoms of the aromatic ring of the salicylate ligand are disordered over two sites with equal occupancy and one of the lattice DMF molecules is partially disordered over two positions, of approximately equal occupancy.
A blue-green crystalline product formed rapidly. The precipitate was filtered off, washed with MeOH and absolute Et 2 O, and dried in vacuo. The dried precipitate was dissolved in DMF to yield a blue-green solution that was allowed to evaporate at room temperature. Blue-green crystals suitable for X-ray diffraction studies were obtained after two weeks. Yield, 0.12 g (67%). Analysis found: C 53.63, H 5.18, N 14.07, Cu 7.09%. C 40 H 46 ClCuN 9 O 9 requires: C 53. 45,H 5.15,N 13.95,Cu 7.41%.

Refinement
The aromatic ring of the salicylate ligand was disordered over two sites and from refinement, these were determined to be of equal occupancy. One of the lattice dimethylformamide molecules is partially disordered over two positions and from refinement, the major component was found to have an occupancy factor = 0.552 (15). All H atoms were geometrically positioned and refined using a riding-model approximation with C-H distances ranging from 0.95 to 0.99 Å and O-H = 0.83 (1) Å, and with U iso (H) = 1.2U eq (C) or U iso (H) = 0.52U eq (O).
supplementary materials sup-2 Figures Fig. 1. Molecular structure and atom numbering for the components of (I). Hydrogen atoms have been omitted for clarity and the displacement ellipsoids are shown at the 30% probability level. The salicylate anion is disordered over two positions of equal occupancy and one of the lattice dimethylformamide molecules is partially disordered over two positions, only one orientation of each is shown for reasons of clarity.