Syntheses and characterization of thallium(I) complexes with 3-nitrophenoxide [Tl(3-np)], 4-nitrobenzoate [Tl(4-nb)] and 2,4-dinitrophenoxide [Tl(2,4-dnp)]:: X-ray crystal structures of [Tl(3-np)]n and Tl(2,4-dnp) (two new polymeric compounds)

Complexes thallium(I)3-nitrophenoxide [Tl(3-np)], thallium(I)2,4-dinitrophenoxide [Tl(2,4-dnp)] and thallium(I)4-nitrobenzoate [Tl(4-nb)] have been synthesized using a direct reaction between TlNO3 and the appropriate ligand. The complexes have been isolated and characterized by IR spectra and CHN elemental analyses. The structures of [Tl(3-np)](n) and [Tl(2,4-dnp)] have been confirmed by X-ray crystallography. The single crystal X-ray crystallography of [Tl(3-np)](n) shows the complex to be a one-dimensional polymer as a result of bridging 3-nitrophenoxide ligands. The Tl atoms have an unsymmetrical three-coordinate, O-3 geometry (three oxygen atoms of the 3-nitrophenoxide ligand). The crystal structure of [Tl(2,4-dnp)] shows the complex to be a three-dimensional polymer as a result of bridging 2,4-dinitrophenoxide ligands. The Tl atoms have an unsymmetrical two-coordinate, O-2 geometry (two oxygen atoms of the 2,4-dinitrophenoxide ligand). The arrangement of the 3-nitrophenoxide and 2,4dinitrophenoxide ligands suggests a gap in coordination geometry around the Tl(I) ions, occupied possibly by a stereoactive lone pair of electrons on Tl(I). There is a pi-pi stacking interaction between the parallel aromatic rings belonging to adjacent chains in the compounds that may help to increase the 'gap' in coordination geometry around the Tl(I) ions. (C) 2002 Elsevier Science Ltd. All rights reserved.