Complexation of Cm(iii) and Eu(iii) with CyMe₄-BTPhen and CyMe₄-BTBP studied by time resolved laser fluorescence spectroscopy

Abstract

The complexation of Cm(III) and Eu(III) with 2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-1,10-phenanthroline (CyMe4-BTPhen) and 6,6'-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-2,2'-bipyridine (CyMe4-BTBP) in methanolic solution was investigated by TRLFS. For both ligands, the 1:2 complex with the particular metal ion is the only species observed in equilibrated samples. The species distribution for various ligand concentrations was determined and stability constants of the 1:2 complexes were derived (log β2 = 13.8 ± 0.2 (Cm(III)-CyMe4-BTPhen), log β2 = 11.6 ± 0.4 (Eu(III)-CyMe4-BTPhen), log β2 = 12.4 ± 0.3 (Cm(III)-CyMe4-BTBP) and log β2 = 11.3 ± 0.3 (Eu(III)-CyMe4-BTBP)). Biphasic experiments in combination with TRLFS studies on the organic phase revealed the formation of ternary complexes with two CyMe4-BTPhen or -BTBP molecules and additional coordination of a nitrate anion as species formed during the extraction process.

Solvent Extraction and Fluorescence Spectroscopic Investigation of the Selective Am(III) Complexation with TS-BTPhen

“…The observed bathochromic shifts of the emission bands of the complex species are characteristic of the formation of a 1:1 and a 1:2 complex with a strong tetradentate N-donor ligand like TS-BTPhen [20,27,29] . Peak deconvolution was carried out, providing the spectra of the pure components shown in Figure 6.…”

“…[20] [27] and is attributed to the greater degree of preorganization of the BTPhen ligand. has a smaller effect on the final stability constant of the TS-BTPhen complex compared to that of SO 3 -Ph-BTBP.…”

Regioselective Synthesis of V-Shaped Bistriazinyl-phenanthrolines

“…Both 1 H-and 13 C NMR Synthesis of 4XPhBTPhen where X = Br, Cl (15,19) was performed in a similar manner as for 11, following the synthetic route C (Scheme 2). However, the halo derivative of 5,…”

“…[7][8][9] The CyMe 4 -BTBP 10 ligand is now considered to be a standard reference ligand for development of An/Ln nuclear separation processes. The advent of BTPhen ligands 2,[11][12][13] improved the kinetics of complexation and CyMe 4 -BTPhen 2,11,12,14,15 is today a promising alternative to CyMe 4 -BTBP. BTPhen ligands complex An(III)/Ln(III) cations in a 2:1 ratio; two BTPhen molecules donate eight nitrogen atoms to bind one cation.…”

N,N,N’,N’-Tetrabutyl-1,10-phenanthroline- 2,9-dicarboxamide as Very Effective Extraction Agent for Trivalent Europium and Americium

“…High selectivity of actinides/lanthanides separation has been achieved when polynitrogen extractants were employed. [1][2][3][4][5][6][7][8][9] However, in spite of very high separation factors for americium/europium separation, some ligands proposed so far have demonstrated some disadvantages (e. g., low chemical stability, slow kinetics, and limited solubility in diluents).…”