Crystal structure of {6,6'-dibenzoyl-4,4'-di-tert-butyl-2,2'-[(ethane-1,2-di-yl)di-nitrilo-bis-(phenyl-methanylyl-idene)]diphenolato-κ(4) O (1),N,N',O (1')}nickel(II).

Abhishek K Gupta,Anjan Sil,Ray J Butcher

doi:10.1107/s2056989015021052

Abstract

The mononuclear title complex, [Ni(C50H46N2O4)], crystallizes in the triclinic space group P-1, with two mol-ecules in the asymmetric unit (Z' = 2). Each Ni(II) atom has a slightly distorted square-planar geometry [ω = 3.91 (5)° and 2.04 (7)°] defined by the two phenolate O and two imine N atoms of the tetra-dentate Schiff base ligand. The dihedral angles between the central phenolate ring and peripheral phenyl rings are 60.5 (2)/70.0 (2) and 86.4 (2)/56.1 (2)° in mol-ecule A, and 89.43 (19)/18.0 (2) and 63.87 (19)/68.2 (2)° in mol-ecule B. The two central phenolate rings are twisted by angles of 19.37 (19) and 19.36 (18)° in the two mol-ecules. The packing is stabilized through intra- and inter-molecular C-H⋯O and C-H⋯π inter-actions, forming chains parallel to the b axis. The tert-butyl groups in one of the two mol-ecules are positionally disordered with a refined occupancy ratio of 0.707 (13):0.293 (13).

Highlights

The mononuclear title complex, [Ni(C50H46N2O4)], crystallizes in the triclinic space group P1, with two molecules in the asymmetric unit (Z0 = 2)
The dihedral angles between the central phenolate ring and peripheral phenyl rings are 60.5 (2)/70.0 (2) and 86.4 (2)/
The packing is stabilized through intraand intermolecular C—H O and C—H interactions, forming chains parallel to the b axis

Summary

Chemical context

Transition metal Schiff base complexes with N2O2 donor sets have attracted much attention in material science (Sukwattanasinitt et al, 2003; Thurston et al, 2003), catalysis (Martın et al, 2015; Gupta & Sutar, 2008; Cozzi, 2004) and in drug design. (Sun et al, 2007). A NiII complex with a tetradentate Schiff base having an oxidized methylene arm has been described (Gupta et al, 2015). We report the synthesis and crystal structure of an NiII complex with a similar tetradentate Schiff base containing an unoxidized methylene arm. The molecular structure of one of the independent molecules (B) of the title compound, showing the atom labelling.

Structural commentary

Synthesis and crystallization

Refinement