Molecular insight into the mode-of-action of phosphonate monolayers as active functions of hybrid metal oxide adsorbents. Case study in sequestration of rare earth elements

Abstract

Organic–inorganic hybrid adsorbents for separation of rare earth elements were prepared by grafting of amino phosphonic acid ligands onto mesoporous TiO2. Their structure and capacity were elucidated using X-ray studies of molecular model compounds.

Titanium phosphonate oxo-alkoxide “clusters”: solution stability and facile hydrolytic transformation into nano titania

“…Detailed crystallographic information for compounds 1 to 7 are given in ESI Table 1 It is important to note that the structures obtained on reux are apparently the same as those obtained on solvothermal synthesis as testied in particular by the structure of 2 (see below) that is formed on both types of synthesis. 20 Its pentanuclear core has been observed in numerous products of solvothermal synthesis. In general, the structure of a modied (oxo) alkoxide demonstrates a dense packing of cations and ligands.…”

“…Sizes range from dinuclear complexes 16 to nano-size complexes [Ti 26 O 26 (OEt) 39 (PhenylPO 3 ) 6 ]Br. 17 Because of the high affinity of the phosphonate group to metal oxide surfaces, including titania, 18,19 it provides an attractive anchor group for functionalizing inorganic nanoparticles with organic ligands for applications such as hybrid nanoadsorbents, 20 organic-inorganic hybrid materials, 21 mesoporous titanium phosphonate structures for catalysis 22,23 and for biological applications. Phospholipids are a major constituent of the cell membrane.…”

Mixed‐Ligand Titanium “Oxo Clusters”: Structural Insights into the Formation and Binding of Organic Molecules and Transformation into Oxide Nanostructures on Hydrolysis and Thermolysis

“…Understanding that oxo complexes are true precursors of oxide materials, and that they are potential models for the nucleation of oxide phases in the sol–gel process, as well as being models for the surface structure of oxide particles, has become one of the strongest sources of recent interest regarding the structure and reactivity of these compounds. Valuable insights have been obtained into the structure of heterogeneous titania‐based catalysts and into the surface structure and reactivity of hybrid TiO 2 ‐based adsorbents . A new source of interest in oxo complexes emerged with the works of Tshuva et al, demonstrating the bioactivity and anti‐inflammatory and cytostatic effects of the phenoxide complexes of titanium , .…”

Surface Modification of SnO2with Phosphonic Acids

“…Titania-based adsorbents can be surface modified for potential uses in various applications using organic monolayers carrying a wide range of organic functionalities [30]. Surface modification allows TiO 2 nanoparticles to be stabilized in both aqueous [13] and hydrocarbon [31,32] media.…”