Exploring differences in various Nb(V)- and Ta(V) tropolonato complexes by a solid-state structural comparison study

Abstract

Niobium and tantalum are chemical 'twins' of the vanadium triad of the periodic table and are notoriously difficult to separate from one another and from their naturally occurring ores, due to their near-identical physical and chemical properties (Agulyansky, 2004). This similarity in behaviour has been ascribed mainly to the lanthanide contraction of the elements and also their comparable ionization energies (Hubert-Pfalzgraf, Postel and Reiss, 1987). Although the separation methods currently applied on an industrial scale, such as solvent extraction and chlorination, have been successful, these techniques remain very laborious, expensive and evolve significant chemical waste (Bose and Gupta, 2001). Accordingly, there is substantial scope for improvements in the metallurgical methods of purification of niobium and separation from tantalum.The key to the effective and simplified separation of these elements could possibly be found in the differences in the chemical properties of two similar organic chelated moieties of these metals. Interestingly, a detailed literature review revealed a considerable shortage of knowledge in relation to the chelation behaviour of tantalum and niobium with different organic bidentate or multidentate ligands (Allen, 2002). In fact, only a single study by Muetteries and Wright (1965) The solution-state investigation of the formation of these compounds was quite thorough, but not much attention was given to the solid-state characteristics of the compounds (Muetteries and Wright, 1965). With this in mind, a detailed, low-temperature crystallographic investigation of the coordi- tropolone, stability, geometry, tantalum, niobium.

Synthesis, structural and theoretical studies on new morpholino acetamide ligand and rare earth metal complexes and corrosion Inhibition Effect

“…[13] Tantalum is the chemical 'twins' of the vanadium triad of the periodic table, and their near-identical physical and chemical qualities make them infamously hard to isolated from one another and from their naturally happening ores. The lanthanide contraction of the elements, as well as their identical ionization energies, have been attributed to this parallelism in behavior [14]. Titanocene dichloride, butotitane and related titanium compounds have reached up to second stage clinical trials.…”

Synthesis, characterization, antibacterial, antioxidant activities, density functional theory, and molecular docking studies of new organic metal complexes and links to application of corrosion inhibitors

“…This symmetry in behavior has been explained by the fact that the elements' lanthanide contraction and ionization energies are the same. [7] Second-stage clinical trials for Titanocene dichloride, butotitane, and also associated titanium complexes have been completed. The initial breakdown of the creations within the serum, their small solubility in the almost impartial water environment, and also the incapability to completely understand the mechanism of their biological impact were all negative outcomes throughout these experiments.…”