Complexes of technetium with diphosphonate ligands are widely used for the imaging and diagnosis of bone disease and most especially metastatic bone cancer. Analogous complexes of radioactive rhenium ((186)Re) with the ligand H(4)HEDP, 1,1-hydroxyethylidenediphosphonate, have been shown to be effective palliatives for the treatment of the intense pain associated with metastatic bone cancer. We have synthesized several of these analogs using nonradioactive Re and have structurally characterized them using EXAFS (extended X-ray absorption fine structure) spectroscopy. One complex synthesized via the substitution reaction of HEDP with trans-[(py)(4)(O)(2)Re]Cl in absolute ethanol appears to be the 1:1 salt of the tris-HEDP complex anion with the starting Re cation, [(py)(4)(O)(2)Re][Re(H(2)HEDP)(3)]. Three other materials, all synthesized via reduction of perrhenate by stannous chloride in the presence of excess H(4)HEDP ligand, are quite different in structure from the material formed by substitution. The principal difference is that each of these contains Re-Re bonds and is formulated as oligomers. The material with a large excess of reductant has Re-Re bonds of ca. 2.4 Å and is best modeled as a linear tetramer of rhenium atoms bridged by HEDP ligands which also bind an equivalent number of tin atoms with additional HEDP ligands. It is formulated as Li(x)()[Re(4)(OH)(2)Sn(4)(HEDP)(12)]. The material formed with the least amount of reducing agent is best modeled as a triangular cluster of rhenium atoms bicapped by two HEDP ligands and bridged to three tin atoms by HEDP to form a complex Li(x)()[Re(3)Sn(3)(HEDP)(8)]. It also has Re-Re bonds but of a significantly longer distance, ca. 2.8 Å. A material with an intermediate amount of reducing agent, prepared in a manner most closely resembling the medically effective palliative agent, appears to contain a mixture of these, and perhaps other, oligomers.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ic960980h | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
High-pressure synthesis of Ruddlesden-Popper nitrides.
Nat Chem
October 2024
Department of Chemistry, Ludwig-Maximilians-Universität München, Munich, Germany.
Layered perovskites with Ruddlesden-Popper-type structures are fundamentally important for low-dimensional properties, for example, photovoltaic hybrid iodides and superconducting copper oxides. Many such halides and oxides are known, but analogous nitrides are difficult to stabilize due to the high cation oxidation states required to balance the anion charges. Here we report the high-pressure synthesis of three single-layer Ruddlesden-Popper (KNiF type) nitrides-PrReN, NdReN and CeTaN-along with their structural characterization and properties.
View Article and Find Full Text PDFTaming Super-Reduced Bi Radicals with Rare Earth Cations.
J Am Chem Soc
April 2023
Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States.
Here, we report the synthesis of two new sets of dibismuth-bridged rare earth molecules. The first series contains a bridging diamagnetic Bi anion, (Cp*RE)(μ-η:η-Bi), (where Cp* = pentamethylcyclopentadienyl; RE = Gd (), Tb (), Dy (), Y ()), while the second series comprises the first Bi radical-containing complexes for any d- or f-block metal ions, [K(crypt-222)][(Cp*RE)(μ-η:η-Bi)]·2THF (, RE = Gd (), Tb (), Dy (), Y (); crypt-222 = 2.2.
View Article and Find Full Text PDFCoordination versus Insertion: On the Interaction of 5 d-Transition Metal Carbonyl Clusters with Silver(I).
Chemistry
June 2023
Institut für Anorganische und Analytische Chemie and, Freiburg Materials Research Center FMF, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg, Germany.
The title silver(I) complex salts [Ag{Re (CO) }{Re(CO) } ] [Al(OR ) ] (AgRe ; OR =-OC(CF ) ) and [Ag{Ir (CO) } ] [Al(OR ) ] (AgIr ) form upon reaction of Ag [Al(OR ) ] and the transition metal carbonyls (TMCs) Re (CO) and Ir (CO) respectively. The solid-state structure of the AgRe cluster shows an unexpected asymmetric coordination motif, wherein the silver(I) cation has inserted into the Re-Re bond of one Re (CO) moiety, while the other dirhenium carbonyl coordinates only over one metal atom towards the silver(I) cation. The AgIr cluster is formed by the edge-on coordination of two Ir tetrahedra and the silver cation in a D symmetric fashion with a torsion angle of 46.
View Article and Find Full Text PDFFerroelastic-Ferroelectric Multiferroicity in van der Waals Rhenium Dichalcogenides.
Adv Mater
May 2022
Department of Physics, Yonsei University, Seoul, 03722, Republic of Korea.
2D multiferroics with combined ferroic orders have gained attention owing to their novel functionality and underlying science. Intrinsic ferroelastic-ferroelectric multiferroicity in single-crystalline van der Waals rhenium dichalcogenides, whose symmetries are broken by the Peierls distortion and layer-stacking order, is demonstrated. Ferroelastic switching of the domain orientation and accompanying anisotropic properties is achieved with 1% uniaxial strain using the polymer encapsulation method.
View Article and Find Full Text PDFBenchmark studies on the large errors of calculated binding energies in metallophilic interactions.
J Chem Phys
March 2022
Department of Chemistry, Anhui University, 111 Jiulong Road, Hefei, Anhui 230601, China.
Aurophilicity is a d-d closed-shell interaction, which is repulsively calculated by the Hartree-Fork (HF) method, whereas binding energies (E) are largely overestimated under the second-order Møller-Plesset (MP2) method, compared to the coupled cluster singles and doubles with perturbative triples [CCSD(T)] method. The unusual energy errors between different wave functional methods were also verified in other closed-shell metallophilic systems and even were taken as a label of metallophilic interaction. Here, we performed a benchmark study on a collection of structures with weak interactions, sp-sp bonds, sp-d bonds, and d-d bonds, to investigate the influence factor of the errors of HF and MP2 methods.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!