Crystal structure of bis(o-acetamidobenzoato-k2:O:O2)-(1,10- phenanthroline-k2:N1:N2)copper(II), Cu(C12H8N2)(C9H8NO3)2

Abstract

Source of materialAmixture of o-acetamidobenzoic acid (0.036 g, 0.2 mmol), copper sulfate (0.025 g, 0.1 mmol) and 1,10-phenanthroline (0.020 g, 0.1 mmol) was dissolved in 15 ml of methanol. The pH value of the resultant mixture was adjusted to about 6.0 -6 .5 by adding three drops of triethylamine solution and the reaction was kept under water-bath condition at 333 Kf or 25 h. Afterwards, the mixture was filtered, and the filtrate was cooled to room temperature slowly. Deep blue single crystals suitable for X-ray diffraction analysis were obtained after fifteen days. Experimental detailsHatoms bound to Catoms were placed in calculted positions and treated as riding on their parent atoms, with d(C-H) =0.95 Å, U iso (H) =1.2 U eq (C) (aromtic) and d(C-H) =0.95 Å, U iso (H) = 1.5 U eq (C) (methyl). Hatoms attached to Natom was initially located in adifference Fourier map and restrained with d(N-H) = 0.88 Å and U iso(H) =1.2 Ueq(N). DiscussionThe study of the structural, spectroscopic, and electronic properties of metal centers present in biological systems is crucial to understand their role in nature [1,2]. These centers are often modeled by using small molecules containing donor atoms that reproduce the coordination around the metal ion [3,4]. The use of simple metal-containing systems with low molecular weight ligands is useful to understand the correlation between magnetic, electronic, and structural properties in more complex systems [5,6]. For this reason, the synthesis of complexes oriented to mimic metal sites of different types of metalloproteins constitutes an important branch in both inorganic and organic chemistry [7,8]. Copper and cobalt are present in adiverse group of metalloenzymes, in which the metal ions are coordinated by N, Oand S atoms. The crystal structure of the title complex contains a[ Cu(1,10-phen)(C 9 H 8 NO 3 ) 2 ]unit. The copper(II) ion is coordinated by two nitrogen atoms from one 1,10-phenanthroline molecule, four oxygen atoms from two o-acetamidobenzoate anions, forming a distorted octahedron with O1 and O1A at the axial positions and O2, O2A, N1 and N1A in the equatorial plane. The bond angle of O1-Cu1-O1A is 133.05°.Atthe equatorial plane, the bond angles N1-Cu1-N1A, N1A-Cu1-O2A, O2A-Cu1-O2 and O2-Cu1-N1 are 81.3(2)°,9 2.9(1)°,9 3.3(1)°and 92.9(1)°,r espectively, with the sum of 360.28°.The bond length Cu1-O1 is 2.648(2) Å,indicating weak coordination bonds between the carbonyl oxygen atoms of o-carboxylaminobenzoate and the copper ion [8]. In the complex, the coordinated carbonyl oxygen atoms and the nitrogen atoms of o-acetamidobenzoate ligands are linked by strong hydrogen bonds: d(N8-H8···O1) =1 .940 Å, ∠N8-H8···O1= 139.0°.T here exist weak hydrogen bonding interactions betweenthe o-acetamidobenzoate ligands and 1,