Long story short: donor set symmetry in [Eu(DOTA)(H₂O)]⁻crystals determines the electronic structure

Abstract

Lanthanide complexes of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid DOTA have been studied in great detail due to their use as MRI contrast agents. Since the first report from Desreux in 1980, the Ln.DOTA...

Contrasting impact of coordination polyhedra and site symmetry on the electronic energy levels in nine-coordinated Eu(iii) and Sm(iii) crystals structures determined from single crystal luminescence spectra

“…Single crystals of Na[Eu(DOTA)H 2 O]•4H 2 O have previously been analysed by Thomsen et al and Parker et al [77][78][79][80] Our spectra are consistent with their spectra. The failure of the empirical model and the predictions in Table 3 have been described previously.…”

LnDOTA puppeteering: removing the water molecule and imposing tetragonal symmetry

“…27 The water exchange rate is faster in the TSA isomers. 24 Indeed, it seems to be facilitated by its interaction with the bulk water (outer sphere) which is stronger in the TSA form because the Ln 3+ ion sinks into the DOTA pocket, 19,[27][28][29] making the Ln-OH 2 bond longer (i.e. the interaction weaker).…”

Donor Radii in Rare-Earth Complexes

“…A relatively small number of X-ray structures analyzed here contained protonated carboxylate groups (13 data points), which display Δ d values in the range of 0.010–0.115 Å. 81 − 85 Thus, protonation of a carboxylate group provokes only a slight increase of the Ln–O c bond distances. Protonation of coordinated phosphonate groups does not have any significant effect (−0.072 < Δ d < 0.044 Å).…”