[6,13-Bis(2,4-dichlorobenzoyl)-5,7,12,14-tetramethyldibenzo[b,i][1,4,8,11]tetraazacyclotetradecinato- κ4 N]nickel(II) acetone monosolvate

In the title complex, [Ni(C36H26Cl4N4O2)]·C3H6O, two 2,4-dichlorobenzoyl groups are grafted onto the methine groups of the NiII complex Ni(tmtaa) (H2tmtaa = 5,7,12,14-tetramethyl-4,11-dihydrodibenzo[b,i][1,4,8,11]tetraazacyclotetradecine). The complex has the shape of a saddle. The Ni atom is tetracoordinated by the four N atoms of the macrocycle, forming a slightly tetrahedrally distorted square-planar geometry. The metal is displaced by 0.0101 (8) Å from the N4 mean plane. The aromatic rings of the 2,4-dichlorobenzoyl groups form dihedral angles of 87.1 (2) and 82.1 (2)° with the N4 mean plane


Experimental
Crystal data [Ni(C 36 H 26  H 2 tmtaa, a versatile ligand for transition and main group metals, is a macrocyclic compound with a 14-membered ring and has a structure and properties similar to porphyrin and phthalocyanine. The distinctive individual characteristics of this synthetic macrocycle make it interesting in a wide range of chemical areas (Cotton et al., 1990;Mountford, 1998).
The syntheses of modified free H 2 tmtaa or tmtaa complexes through substitution at the γ and γ′ positions have been extensively researched (Sakata et al., 1996;Eilmes et al., 2001;Shen et al., 2008). As a continuation of the investigation on the reactivity of γ and γ′ positions in Ni(tmtaa) (Jäger, 1969), we herein report the synthesis and crystal structure of the title compound.
The molecular structure of the title compound is illustrated in Fig. 1. The non-planar saddle-shaped conformation of the Nitmtaa is maintained with two 2,4-dichlorobenzoyl groups folding towards the central metal. The dihedral angle between the benzene rings of the tmtaa ligand is 62.4 (2)°. The Ni atom is coordinated to four N atoms of tmtaa in a sligthly tetrahedrally distorted coordination geometry and protrudes from the N 4 plane by only 0.0101 (8) Å. The dihedral angle between two aromatic rings in the grafted substituents is 15.98° and both of them are almost perpendicular to the N 4 plane forming dihedral angles of 87.1 (2) and 82.1 (2)°, respectively. The Ni-N bond distances range from 1.857 (4) to 1.862 (4) Å with a mean value of 1.860 (4) Å. In the crystal structure (Fig. 2), no hydrogen bonds or other weak intermolecular interactions are observed.

Experimental
After a solution of Ni(tmtaa) (0.602 g, 1.50 mmol) and triethylamine (2 ml) in dry toluene (50 ml) was stirred at room temperature under nitrogen atmosphere for 10 min, a solution of 2,4-dichlorobenzoyl chloride (0.670 g, 3.20 mmol) in dry toluene (50 ml) was slowly added dropwise and the reaction mixture was further stirred at 80°C for 12 h. After been cooled to room temperature, the reacted mixture was filtered to eliminate the triethylamine hydrochloride formed.
Evaporation of the filtrate resulted in a dark green powder. The powder was purified and separated on an alumina chromatographic column using petroleum ether and ethyl acetate (8:1 v/v) as the eluant. The product was recrystallized from acetone to give dark green crystals of the title compound in a yield of 0.652 g (54%).

Refinement
All H atoms were positioned geometrically and refined using a riding model with C-H = 0.93 and 0.96 Å for aryl and methyl H-atoms, respectively. The U iso (H) were allowed at 1.2U eq (C) or 1.5U eq (C) for methyl H atoms.

Figure 1
The molecular structure of the title compound, showing 30% probability displacement ellipsoids.
where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.002 Δρ max = 1.65 e Å −3 Δρ min = −2.37 e Å −3 Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.