A thallium(I) tetranuclear cubic cage unit in an interpenetrated supramolecular polymer: A new precursor for the preparation of Tl2O3 nanostructures

A new thallium(I) supramolecular polymer, [Tl4(μ3-4-BN)4]n (1) [9-HBN = 4-hydroxy benzonitrile], with a disordered cubic cage structural unit has been synthesized and characterized. The single-crystal X-ray data of compound 1 shows one type of TlI ion in the tetranuclear cubic cage structure with a coordination number of three. In addition to two intra cage thallophilic interactions in 1, each thallium(I) atom has a weak Tl⋯N secondary interaction with the nitrile group of the 4-BN− ligand. Finally the Tl-ions attain the O3Tl⋯NTl2 coordination sphere with a stereo-chemically ‘active’ electron lone pair on the metal. The self assembly between the benzonitrile groups of one cubic cage structure with an adjacent one with a Tl⋯N short contact, by π–π stacking and weak hydrogen bonding interactions, results in the formation of a new interpenetrating thallium(I) supramolecular polymer. The thermal stability of 1 was studied by thermo gravimetric (TG) and differential thermal analyses (DTA). Nanostructures of thallium(III) oxide were prepared from a calcination process of compound 1 fine powder at 743 K. These nanostructures were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM).

Nano-structures of thallium(III) oxide were prepared by the calcination process of [Tl4(μ3-4-BN)4]n (1) [9-HBN = 4-hydroxy benzonitrile] at 743 K. In this compound, four thallium atoms and four oxygen atoms of 4-BN− anions form a distorted tetranuclear cubic cage unit. The self assembly between the benzonitrile groups of one cubic cage unit with another one results in the formation of a new interpenetrating thallium(I) supramolecular polymer.Figure optionsDownload as PowerPoint slideHighlights
► Tl2O3 nanostructures were prepared by the calcination process of [Tl4(μ3-4-BN)4]n.
► The microemulsion-based methodology resulted in formation of TlBr nanostructures.
► Tl2O3 with a nanostructural surface was fabricated from thermal treatment of TlBr.