{2-(4-Hydroxyphenyl)-2-[(3-methoxy-2-oxidobenzylidene)amino-κ2 O 2,N]propanoato-κO}(1,10-phenanthroline-κ2 N,N′)copper(II) dihydrate

In the title complex, [Cu(C17H15NO5)(C12H8N2)]·2H2O, the central CuII ion is five-coordinate, bound to one N atom and two O atoms from the Schiff base ligand and by two N atoms from a 1,10-phenanthroline ligand in a distorted square-pyramidal configuration. In the crystal, intermolecular O—H⋯O and C—H⋯O hydrogen bonds form a two-dimensional network parallel to (001).

In the title complex, [Cu(C 17 H 15 NO 5 )(C 12 H 8 N 2 )]Á2H 2 O, the central Cu II ion is five-coordinate, bound to one N atom and two O atoms from the Schiff base ligand and by two N atoms from a 1,10-phenanthroline ligand in a distorted squarepyramidal configuration. In the crystal, intermolecular O-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds form a two-dimensional network parallel to (001).

Related literature
For background to Schiff bases and the applications of Schiff base-copper complexes, see: Chohan et al. (1998);Nath et al. (2001); Raso et al. (1999);Yamada (1966). For the structure of a similar complex with a five-coordinate Cu II ion, see: Qiu et al. (2008).
{2-(4-Hydroxyphenyl)-2-[(3-methoxy-2-oxidobenzylidene)amino-2 O 2 ,N]propanoato-O}(1,10phenanthroline-2 N,N')copper(II) dihydrate X. Pu, L. Li, J. Dong and B. Jing Comment Schiff bases still play an important role as ligands in metal coordination chemistry even after almost a century since their discovery (Yamada, 1966). It has been reported that amino acid Schiff bases and their first row transition metal complexes exhibit fungicidal, bactericidal, antiviral, and antitubercular activity (Chohan et al., 1998;Nath et al., 2001). Considerable efforts have been devoted to copper(II) complexes of tridentate N-alkylidene or N-arylidene alkanato Schiff base ligands, due to their structural diversity, electrochemical properties as well as a potential model for a number of important biological systems (Raso et al., 1999). Herein, we report the synthesis and crystal structure of a new copper(II) complex with a tridentate Schiff base ligand derived from the condensation of L-tyrosine and o-vanillin, with a 1,10-phenanthroline coligand.
As shown in Fig 1, the central Cu II ion is five coordinate, bound to two O atoms and one N atom of the Schiff base ligand and two N atoms of the 1,10-phenanthroline ligand, forming a distorted square-pyramidal geometry. The O1, O4, N1, and N2 atoms are in the equatorial plane, and N3 is in the axial position. The Cu II ion lies 0.5068 ( In the crystal, the combination of intramolecular and intermolecular hydrogen bonds (Table 2) leads to a two-dimensional network (Fig. 2).
Experimental L-Tyrosine(1 mmol, 146.2 mg) and potassium hydroxide (1 mmol, 56.1 mg) were dissolved in hot methanol (10 ml) and added successively to a methanol solution of o-vanillin (1 mmol, 152.2 mg). The mixture was then stirred at 323 K for 2 h. Subsequently, an aqueous solution(2 ml) of cupric acetate monohydrate (1 mmol, 199.7 mg) was added dropwise and stirred for 2 h. A methanol solution (5 ml) of 1,10-phenanthroline (1 mmol, 198.2 mg) was added dropwise and stirred for 4 h. The solution was held at room temperature for ten days, whereupon green block-shaped crystals suitable for X-ray diffraction were obtained.

Refinement
The maximum residual density peak in the final difference Fourier map is 1.189 e Å -3 , it is 2.67Å and 4.018Å from H19 and Cu, respectively.
H atoms of the water molecules were found in difference Fourier maps and refined isotropically, with the O-H distances restrained to 0.85 (2)Å and with U iso (H) = 1.2U eq (O). All other H atoms were placed in geometrically calculated supplementary materials sup-2 positions (C-H = 0.93 -0.98 Å)and allowed to ride on their respective parent atoms, with U iso (H) = 1.2U eq (C phenyl ) or 1.5U eq (C methyl ) and O hydroxyl ). Fig. 1. The structure of the title compound, drawn with 30% probability displacement ellipsoids.