Syntheses and structural determination of binuclear nine-coordinate (NH₄)₄[Sm^III₂(Httha)₂]·16H₂O and 2-D ladder-like binuclear nine-coordinate (NH₄)₄[Sm^III₂(dtpa)₂]·10H₂O

Synthesis and Photochemical Studies on Gallium and Indium Complexes of DTPA-PEG3-ArN3 for Radiolabeling Antibodies

“…Diethylenetriaminepentaacetic acid (DTPA) is a high affinity binder of several metal cations. It bears three tertiary amines and five sterically unconstrained carboxylic acids that can coordinate metal ions or be used as functionalization handles. , The DTPA chelate has been widely used in nuclear chemistry due to the fact that it forms stable coordination compounds with various metal ions including indium (formation constant log β = 29.0–29.5), yttrium (log β = 21.2–22.5), gallium (log β = 25.5), and lanthanides like gadolinium (log β = 22.46). ,,− Several 111 In-radiolabeled antibodies that incorporated the DTPA chelate have received clinical approval for SPECT imaging. These include 111 In-satumomab pendetide for the diagnosis of colorectal and ovarian carcinomas, and 111 In-capromab pendetide for prostate cancer therapy. − …”

Spectroscopic and Computational Characterization of Diethylenetriaminepentaacetic Acid/Transplutonium Chelates: Evidencing Heterogeneity in the Heavy Actinide(III) Series

“…In contrast, ac lear gap,s ignificantly larger than the experimental uncertainty,i so bserved between the MÀO bonds of the Am, Cm, Bk complexes and that of Cf.T he An III ÀOb ond length evolves as follows:2 .41(1), 2.41(1), 2.42(2), and 2.36(1) for Am, Cm, Bk, and Cf,r espectively (Table 1a nd Figure 2). As mentioned above,t he previously published crystal structures of nine Ln III /DTPAc ompounds (Table S4) [28,29,[33][34][35][36][37][38] can be used as ab enchmark for their An counterparts.I nt he Ln 3+ complexes,t he metal is always nonacoordinated by five carboxylate oxygen atoms,t hree nitrogen atoms,a nd one extra oxygen atom coming from either aw ater molecule or ab identate carboxylate.T wo independent EXAFS studies [39,40] have also determined the M À Ob ond lengths for the Gd III /DTPAa nd Eu III /DTPA species and are in excellent agreement with the crystallographic studies,v alidating our use of EXAFS for characterization and allowing for direct comparisons with reported crystal structures (Figure 2).…”

“…Zuschriften made between the macroscopic solution chemistry of Cf 3+ and that of the lighter An 3+ ions. Thec rystallization methods reported in the literature [28,29,[33][34][35][36][37][38] for the Ln III /DTPAc ompounds cannot be applied to the transplutonium systems owing to the large amount of metal needed. However,the geometry of the An III complexes can be optimized computationally.T he corresponding Es system was probed as well, even though EXAFS experiments are currently not possible owing to the limited availability of this element.…”

“…Herein, we selected diethylenetriaminepentaacetic acid (DTPA) as amodel ligand to examine bond trends in solution for the trivalent series of transplutonium elements (Scheme 1). DTPAi sahard-donor chelator with three tertiary amine nitrogen atoms and five unconstrained carboxylate binding units that can act as ar elatively flexible octadentate [28] or nonadentate [29] ligand, depending on the metal center. Aside from the use of its Gd 3+ complex as acontrast agent for magnetic resonance imaging, [30] DTPAis of primary importance in the nuclear chemistry field for multiple reasons.I ti s, as of today,t he only compound approved by the U.S. Food and Drug Administration for use as ac ounter-poisoning drug in the case of internal contaminations with actinides.…”

“…[31] Furthermore,D TPAa nd its derivatives are studied for industrial processes that aim at recycling nuclear waste and separating An from Ln fission products as, for example,i nt he TALSPEAK process. [32] In the frame of this study,D TPAi sa lso convenient because it is one of the rare ligands for which crystal structures of several Ln 3+ complexes have been determined, [28,29,[33][34][35][36][37][38] in addition to two EXAFS data sets [39,40] available on the Eu 3+ and Gd 3+ chelates.D TPAw as also chosen in this study because it exhibits high stability constants with the An 3+ ions (log b 110 % 23 at 25 8 8C) [41] but its affinity towards tetravalent ions is not strong enough to spontaneously oxidize Bk 3+ to Bk 4+ ,a s recently observed for more powerful chelators such as the hydroxypyridinonates. [42] Hence,t he entire aqueous trivalent Am-Cf series can be studied in the presence of DTPA.…”