Bis{2-[(4-bromophenyl)iminomethyl]pyridine-κ2 N,N′}copper(I) tetraphenylborate

In the crystal structure of the title compound, [Cu(C12H9BrN2)2](C24H20B), the copper(I) cation is coordinated by four N atoms of two crystallographically independent 2-[(4-bromophenyl)iminomethyl]pyridine ligands within a distorted tetrahedron.


Experimental
Crystal data  supporting information Acta Cryst. (2008).E64, m1019 [doi:10.1107Much interest has recently been focused on the rational design and construction of novel copper(I) complexes because of their reversible electrochemical behavior, light absorption in the visible spectral region; characteristic structural flexibility, long-lived electronically excited states, intense luminescence and ease of preparation (Armaroli, 2001;Sakaki et al., 2002).In continuation of our interests on this topic (Dehghanpour et al., 2007;Dehghanpour & Mahmoudi, 2007), we report herein the X-ray crystal structure of the copper(I) complex of the Schiff base ligand of (4-bromo-phenyl)pyridin-2-ylmethylene-amine.
The structure of (I) consists of discrete [(C 12 H 9 BrN 2 ) 2 Cu] + cations and [BPh 4 ] -anions (Fig. 1).The copper(I) cation centre has a tetrahedral coordination which shows signficant distortion, mainly due to the presence of the five-membered chelate ring (Table 1).The endocyclic N1-Cu-N2 angle is much smaller than the ideal tetrahedral angle of 109.5 °, whereas the opposite N1-Cu-N4 angle is much wider than the ideal tetrahedral angle.

S3. Refinement
All hydrogen atoms were placed in geometrically calculated positions and refined isotropic using a riding model with

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å
parameters constrained Á max = 0.70 e A ˚À3 Á min = À0.39 e A ˚À3

Figure 1
Figure 1 Crystal structure of the cation (a) and the anion (b) with labeling and thermal ellipsoids drawn at 50% the probability level.Hydrogen atoms are shown as spheres of arbitrary radius.