Lanthanide Paramagnetic Probes for NMR Spectroscopic Studies of Fast Molecular Conformational Dynamics and Temperature Control. 18-Crown-6 Intramolecular Reorientation in Complexes of Cerium(III) Chelates

Abstract

By1 Н dynamic NMR method the conformational reorientation of the 18-crown-6 ether molecules in [(Ce(ptfa)

NMR Study of Paramagnetic Properties and the Kinetics of Hydrolysis of the Dy-tris-tBu-DOTA-ester Complex

“…It should be noted that other complex compounds, which were earlier investigated by 1 H NMR in both organic and aqueous media are characterized by the paramagnetic CS temperature sensitivity in the range from 0 to 1.5 ppm/K. [8,[10][11][12][13][29][30][31] The obtained result indicate that the coordination compounds I, II and III may be considered as the middle sensitive 1 H NMR lanthanide paramagnetic probes for in situ temperature control in solutions. Therefore, complexes I, II and III can be considered as potential reagents for determining the temperature in liquid samples installed in an NMR spectrometer, either directly in reaction media, or for in situ studies of exothermic or endothermic processes.…”

Adducts of aqua complexes of Ln3+with hexahydroxyhexamethylcucurbit[6]uril: potential application in the isolation of heavy lanthanides

“…The coordination chemistry of lanthanides is important, and during the last few decades, an increase in the number of publications devoted to rare-earth coordination compounds has been observed. [1][2][3][4][5][6] This is due to their biological, biochemical, and medical applications, such as their capacity to serve as excellent diagnostic and prognostic probes in clinical diagnostics or as anticancer agents. 2,7,8 Naturally, the chemistry of the lanthanides is a field of great interest to contemporary inorganic chemists.…”

“…The first involves the addition of hydroquinone (Hyq), [31][32][33] whereas the second involves the addition of polychlorido transition metallate anions ([M d-block Cl x ] nÀ ) which act as structure-directing agents and generally lead to the assembly of honeycomb-like frameworks (the so-called ''honeycomb effect'' of [M d-block Cl x ] nÀ anions). [34][35][36] In the present work, a partially substituted cucurbituril derivative, hexahydroxyhexamethylcucurbit [6]uril (HHQ [6]; Fig. 1), 37 has been used as a ligand, and its interaction with a series of lanthanide cations in neutral aqueous solutions has been investigated in the presence of CdCl 2 .…”

“…

The interactions of a series of lanthanide cations (Ln 3+ ) with hexahydroxyhexamethylcucurbit[6]uril (HHQ[6]) have been investigated. The interaction results in the formation of solid crystals of adducts of HHQ [6] with aqua complexes of lanthanide cations of type ([Ln(H 2 O) 8 ] 3+ ) for Ln = Gd-Lu to yield HHQ[6]-Ln(NO 3 ) 3 -CdCl 2 -H 2 O species in neutral solution. Conversely, no solid crystals were obtained for systems containing La, Ce, Pr, Nd, Sm, or Eu.

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Holmium Сomplex with DOTA as NMR Super-Sensitive Temperature Sensor Reagent for Spectroscopic and Tomography Monitoring of Aqueous Systems

“…[3, 5,[18][19][20][21][22][23] В самое последнее время мы больше внимания уде-ляли изучению молекулярной динамики, особенностей парамагнитных свойств и ЯМР термосенсорных воз-можностей комплексов Ln в водных растворах. [6,14,[24][25][26] В настоящее время ведется поиск органических веществ, способных выполнять роль лигандов для получения раз-личных координационных соединений, перспективных в качестве ЯМР-сенсоров для биологических систем.…”