(2,2′-Bipyridine)(2-{1-[2-(dimethylamino)ethylimino]ethyl}-4-methoxyphenolato)copper(II) perchlorate

The Cu atom of the title complex, [Cu(C13H19N2O2)(C10H8N2)]ClO4, has a distorted square-pyramidal geometry with all three of the donor atoms from the N,N′,O-tridentate Schiff base ligand in the equatorial positions and the bipyridine N atoms in an equatorial–axial binding mode. The Cu atom is 0.1801 (11) Å above the N3O mean basal plane.

The Cu atom of the title complex, [Cu(C 13 H 19 N 2 O 2 )-(C 10 H 8 N 2 )]ClO 4 , has a distorted square-pyramidal geometry with all three of the donor atoms from the N,N 0 ,O-tridentate Schiff base ligand in the equatorial positions and the bipyridine N atoms in an equatorial-axial binding mode. The Cu atom is 0.1801 (11) Å above the N 3 O mean basal plane.

Related literature
For the development of efficient catalytic systems for the coupling of CO 2 with heterocycles into polycarbonates, see: Inoue et al. (1969). For the synthesis and catalytic studies of a series of bis-(salicylaldiminato)zinc complexes, see: Darensbourg et al. (2001). For similar complexes, see: Dhar et al. (2006); Shen et al. (2003). For the synthesis, see: Hung & Lin (2009);Hung et al. (2008); For the chemical activity of complexes, see: Noh et al. (2007).

Experimental
Crystal data [Cu(C 13  Financial support from the National Science Council of the Republic of China is gratefully appreciated. Helpful comments from the reviewers are also greatly appreciated.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: RK2135). Bruker (1999  Comment Though many bacteria convert CO 2 into organic compounds by photosynthesis, utilization of CO 2 as a chemical feedstock in industrial and laboratory is rare. Recently, reuse of CO 2 has received great attention because of environmental concern.

References
Polycarbonates (PC) have been wildly used in the modern chemical industry. Co-polymerization of CO 2 with olefins may benefit from reducing the release of CO 2 and generating potential industrial useful PCs. Therefore, there has been increasing interest in the development of efficient catalytic systems for the coupling of CO 2 with heterocycles into polycarbonates (Inoue et al., 1969). One of the major successes is the utilization of epoxides and CO 2 as starting materials to prepare PCs The solid structure of [LCu(bipy)] + ion reveals a monomeric Cu II complex containing a six-member and a five-member ring coordinated from the tridentate salicylideneiminate ligand and a five-member ring coordinated from the bipyridine ligand. The geometry around Cu atom is penta-coordinated with a slight distorted square pyramidal environment in which all three of the N,N,O-tridentate donor atoms and one of the N atoms of the bipyridine lignad sitting on the equatorial plane, and another N atom of the bipyridine ligand at the axial position. The distances between the Cu atom and O1, N1, N2, N3 and N4 are 1.903 (2), 1.964 (2), 2.076 (2), 2.208 (2) and 2.044 (2) Å, respectively which are all within a normal distance for a Cu-O and Cu-N distance. These bond distances are similar to those found in other Schiff base Cu II complexes (Dhar et al., 2006).

Refinement
The methyl H atoms were located and then constrained to an ideal geometry with C-H distances of 0.96 Å and U iso (H) = 1.5U eq (C), but each group was allowed to rotate freely about its C-C bond. All other 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 Å and 0.97 Å and U iso (H) = 1.2U eq (C). Fig. 1. A view of the molecular structure with the atom numbering scheme. The displacement ellipsoids are shown at the 20% probability level. H atoms are presented as a small spheres of arbitrary radius.

Special details
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The 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.