Synthesis and X-ray diffraction study of Zn(II) complexes with o-phthalic acid and aromatic amines

• Published in: Polyhedron 2001-04, Vol.20 (9), p.831-837
• Main Authors: Baca, Svetlana G, Simonov, Yurii A, Gerbeleu, Nicolae V, Gdaniec, Maria, Bourosh, Paulina N, Timco, Grigore A
• Format: Article
• Language: English
• Subjects: Crystal structures; Phthalate complexes; Zinc(II) carboxylates; Zinc(II) complexes
• ISSN: 0277-5387
• DOI: 10.1016/S0277-5387(01)00698-2

New zinc (II) complexes [Zn(Pht)A 2], where Pht 2−=dianion of o-phthalic acid, A=pyridine ( 1), 3-methylpyridine ( 2), 4-methylpyridine ( 3) and [Zn(Pht)A] (A=4-methylpyridine ( 4)) have been synthesised and characterised by X-ray crystallography. The compounds have polymeric structures due to 1,6-bridging ability of the o-phthalate ligand. Polymeric chains exhibit three types of organisation in the crystal. Complexes 1 and 2 have similar structures, where Zn atom is coordinated by two oxygen atoms of two carboxylate groups and two nitrogen atoms of N-containing ligands. Two independent Zn atoms in 3 have different environments: tetrahedral N 2O 2 and distorted square-pyramidal N 2O 3. One of the acid residues behaves as bidentate 1,6-bridge, while the other acts as tridentate (1,6-bridging and 1,3-chelating) ligand. One of the Zn atoms in 4 has a tetrahedral NO 3 geometry, while the second is characterised by a distorted octahedral NO 5 coordination polyhedron. Both phthalate anions are tetradentate and act as syn– syn, syn– anti and monoatomic Zn–O–Zn bridging ligands. The IR spectra are discussed in relation to the crystal structures.