TY - JOUR
T1 - Monomers, Dimers, and Helices
T2 - Complexities of Cerium and Plutonium Phenanthrolinecarboxylates
AU - Cary, Samantha K.
AU - Ferrier, Maryline G.
AU - Baumbach, Ryan E.
AU - Silver, Mark A.
AU - Lezama Pacheco, Juan
AU - Kozimor, Stosh A.
AU - La Pierre, Henry S.
AU - Stein, Benjamin W.
AU - Arico, Alexandra A.
AU - Gray, Danielle L.
AU - Albrecht-Schmitt, Thomas E.
N1 - Funding Information:
This research was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Heavy Elements Chemistry Program, under Award DE-FG02- 13ER16414. Synchrotron studies were supported under the Heavy Element Chemistry Program at the LANL by the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences, U.S. Department of Energy (Kozimor, Lezama, Trujillo). We are grateful for postdoctoral and graduate fellowships from the Glenn T. Seaborg Institute (Ferrier, Stein) and the LANL Directors Postdoctoral Fellowship (La Pierre). Los Alamos National Laboratory is operated by Los Alamos National Security, LLC, for the National Nuclear Security Administration of U.S. Department of Energy (Contract DE-AC52-06NA25396). The synchrotron studies were carried out at the SSRL, a Directorate of the SLAC National Accelerator Laboratory and an Office of Science User Facility operated for the U.S. Department of Energy Office of Science by Stanford University.
Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/5/2
Y1 - 2016/5/2
N2 - The reaction of CeIII or PuIII with 1,10-phenanthroline-2,9-dicarboxylic acid (PDAH2) results in the formation of new f-element coordination complexes. In the case of cerium, Ce(PDA)(H2O)2Cl·H2O (1) or [Ce(PDAH)(PDA)]2[Ce(PDAH)(PDA)] (2) was isolated depending on the Ce/ligand ratio in the reaction. The structure of 2 is composed of two distinct substructures that are constructed from the same monomer. This monomer is composed of a CeIII cation bound by one PDA2- dianionic ligand and one PDAH- monoanionic ligand, both of which are tetradentate. Bridging by the carboxylate moieties leads to either [Ce(PDAH)(PDA)]2 dimers or [Ce(PDAH)(PDA)]1 helical chains. For plutonium, Pu(PDA)2 (3) was the only product isolated regardless of the Pu/ligand ratio employed in the reaction. During the reaction of plutonium with PDAH2, PuIII is oxidized to PuIV, generating 3. This assignment is consistent with structural metrics and the optical absorption spectrum. Ambiguity in the assignment of the oxidation state of cerium in 1 and 2 from UV-vis-near-IR spectra invoked the use of Ce L3,2-edge X-ray absorption near-edge spectroscopy, magnetic susceptibility, and heat capacity measurements. These experiments support the assignment of CeIII in both compounds. The bond distances and coordination numbers are also consistent with these assignments. 3 contains 8-coordinate PuIV, whereas the cerium centers in 1 and 2 are 9- and/or 10-coordinate, which correlates with the increased size of CeIII versus PuIV. Taken together, these data provide an example of a system where the differences in the redox behavior between these f elements creates more complex chemistry with cerium than with plutonium.
AB - The reaction of CeIII or PuIII with 1,10-phenanthroline-2,9-dicarboxylic acid (PDAH2) results in the formation of new f-element coordination complexes. In the case of cerium, Ce(PDA)(H2O)2Cl·H2O (1) or [Ce(PDAH)(PDA)]2[Ce(PDAH)(PDA)] (2) was isolated depending on the Ce/ligand ratio in the reaction. The structure of 2 is composed of two distinct substructures that are constructed from the same monomer. This monomer is composed of a CeIII cation bound by one PDA2- dianionic ligand and one PDAH- monoanionic ligand, both of which are tetradentate. Bridging by the carboxylate moieties leads to either [Ce(PDAH)(PDA)]2 dimers or [Ce(PDAH)(PDA)]1 helical chains. For plutonium, Pu(PDA)2 (3) was the only product isolated regardless of the Pu/ligand ratio employed in the reaction. During the reaction of plutonium with PDAH2, PuIII is oxidized to PuIV, generating 3. This assignment is consistent with structural metrics and the optical absorption spectrum. Ambiguity in the assignment of the oxidation state of cerium in 1 and 2 from UV-vis-near-IR spectra invoked the use of Ce L3,2-edge X-ray absorption near-edge spectroscopy, magnetic susceptibility, and heat capacity measurements. These experiments support the assignment of CeIII in both compounds. The bond distances and coordination numbers are also consistent with these assignments. 3 contains 8-coordinate PuIV, whereas the cerium centers in 1 and 2 are 9- and/or 10-coordinate, which correlates with the increased size of CeIII versus PuIV. Taken together, these data provide an example of a system where the differences in the redox behavior between these f elements creates more complex chemistry with cerium than with plutonium.
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U2 - 10.1021/acs.inorgchem.6b00077
DO - 10.1021/acs.inorgchem.6b00077
M3 - Article
C2 - 27070401
AN - SCOPUS:84968732970
SN - 0020-1669
VL - 55
SP - 4373
EP - 4380
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 9
ER -