Bis[2-(benzyliminomethyl)-4-chlorophenolato-κ2 N,O]nickel(II)

In the mononuclear centrosymmetric title compound, [Ni(C14H11ClNO)2], the NiII atom, lying on a center of symmetry, is four-coordinated by two O atoms and two N atoms from two Schiff base ligands, forming a slightly distorted square-planar environment. The dihedral angle between the two aromatic rings of the ligand is 72.0 (2)°. No significant hydrogen bonding or π–π stacking interactions are observed.

In the mononuclear centrosymmetric title compound, [Ni(C 14 H 11 ClNO) 2 ], the Ni II atom, lying on a center of symmetry, is four-coordinated by two O atoms and two N atoms from two Schiff base ligands, forming a slightly distorted square-planar environment. The dihedral angle between the two aromatic rings of the ligand is 72.0 (2) . No significant hydrogen bonding orstacking interactions are observed.
Financial support by the Phytochemistry Key Laboratory of Shaanxi province (grant No. 02js40) is gratefully acknowledged.

S1. Comment
Recently, we have reported a Schiff base nickel(II) complex (Hu et al., 2005). Owing to the nickel complexes derived from Schiff base ligands possess interesting structures and wide applications (Costes et al., 2005;Wallis & Cummings, 1974;Christensen et al., 1997;Liu et al., 2006); Yu, 2006), we report here the crystal structure of a new Schiff base nickel(II) complex, title compound, (I), Compound (I) is a mononuclear centrosymmetric Ni II complex ( Fig. 1) The Ni atom, lying on the center of symmetry, is four-coordainated by two O atoms and two N atoms from two Schiff base ligands, forming a slightly distorted squareplanar environment ( Table 1). The bond lengths and angles of the ligands show normal values (Allen et al., 1987). The dihedral angle between the two aromatic rings of the ligand is 72.0 (2)°. No significant hydrogen bonding or π-π stacking interactions are observed.

S3. Refinement
All H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C-H distances in the range 0.93-0.97 Å and U iso (H) = 1.2U eq (C).  The molecular structure of (I), showing 30% probability displacement ellipsoids. H atoms have been omitted for clarity.
Unlabelled atoms are related to other labelled atoms by the symmetry operation (-x, 1 -y, -z).

Figure 2
The crystal packing of (I), viewed along the c axis.

Bis[2-(benzyliminomethyl)-4-chlorophenolato-κ 2 N,O]nickel(II)
Crystal data 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.