Metal-Ion Displacement Approach for Optical Recognition of Thorium: Application of a Molybdenum(VI) Complex for Nanomolar Determination and Enrichment of Th(IV)

Abstract

An azine-based molybdenum (Mo(VI)) complex (M1) is exploited for selective detection of thorium (Th(IV)) ions through a metal-ion displacement protocol. Th(IV) displaces Mo(VI) from M1 instantly leading to the formation of the Th(IV) complex, having orange-red emission. Consequently, a red shift of the emission wavelength along with 41-fold fluorescence enhancement is observed. This unique method allows detection of Th(IV) as low as 1.5 × 10 –9 M. The displacement of Mo(VI) from M1 by Th(IV) is established by spectroscopic studies and kinetically followed by the stopped-flow technique. The displacement binding constant for Th(IV) is notably strong, 4.59 × 10 6 M –1 . Extraction of Th(IV) from aqueous solution to the ethyl acetate medium using M1 has been achieved. The silica-immobilized M1 efficiently enriches Th(IV) from its reservoir through solid-phase extraction. Computational studies (density functional theory) support experimental findings.

Exploring a new dinuclear Fe(iii) complex for the fixation of atmospheric CO2 and optical recognition of nano-molar levels of Zn2+ ions

“…Therefore, the above discussion clearly demonstrates our motivation for investigating the optical recognition [35][36][37][38] of the bio-relevant metal ion Zn(II) and the (bio)catalytic application of a new Fe(III) complex.…”

Cyclohexane based Bis‐imine and Salicylic Acid Derived Tripodal Amide for Optical Recognition and Enrichment of Sm3+ and Dy3+

“…The P1 is employed to determine the concentration of Sm 3+ in real water sample following standard addition method [44] . To verify the precision of the method, different concentrations of Sm 3+ are used for recovery studies.…”

An Unsymmetrical bis‐Imine Derivative for Solvent Dependent Rapid Optical Discrimination of Al3+, Zn2+ and OCl−: Combined Experimental and Theoretical Studies

“…The developed probe is successfully applied in real sample analysis of Zn 2 + using standard addition method (Table 1). [8,53] Recovery study is performed using different level of Zn 2 + ion concentration. Known amount of Zn 2 + salt is added to water collected from area of Burdwan Municipality and damodar river.…”

“…[4][5] The function of a sensor may involve several types of interactions between host and guest like hydrogen bonding, probe-cation coordination, aggregation, electrostatic interaction, hydrophobic and van der Waal's interactions etc. [6][7][8] A single probe having significantly different response towards multiple ions is cost effective, time saving and hence, highly desirable for practical application. [9][10] As solvent may alter the nature and energy parameters of the receptor, hence can alter the fluorescence response and selectivity, generally termed as solvatochromic effect.…”

“…In addition, the role of solvent towards the selectivity and sensitivity of detection is noteworthy [4–5] . The function of a sensor may involve several types of interactions between host and guest like hydrogen bonding, probe‐cation coordination, aggregation, electrostatic interaction, hydrophobic and van der Waal's interactions etc [6–8] . A single probe having significantly different response towards multiple ions is cost effective, time saving and hence, highly desirable for practical application [9–10] .…”