A family of rare-earth complexes [RE(III) = Y, La, Gd, Tb, Dy, and Er] with doubly reduced dibenzo[,]cyclooctatetraene (DBCOT) has been synthesized and structurally characterized. X-ray diffraction analysis confirms that all products of the [RE(DBCOT)(THF)][RE(DBCOT)] composition consist of the anionic sandwich [RE(DBCOT)] and the cationic counterpart [RE(DBCOT)(THF)]. Within the sandwich, two elongated π decks are slightly bent toward the metal center (avg. 7.3°) with a rotation angle of 35.9-37.6°. The RE(III) ion is entrapped between the central eight-membered rings of DBCOT in a η fashion. The trends in the RE-COT bond lengths are consistent with the variations of the ionic radii of RE(III) centers. The H NMR spectra of the diamagnetic Y(III) and La(III) analogues illustrate the distinct solution behavior for the cationic and anionic parts in this series. Magnetic measurements for the Dy analogue reveal single-molecule magnetism, which was rationalized by considering the effect of crystal-field splitting for both building units analyzed by electronic structure calculations.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11134502 | PMC |
http://dx.doi.org/10.1021/acs.inorgchem.3c04249 | DOI Listing |
Nature
May 2024
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
Lanthanide rare-earth metals are ubiquitous in modern technologies, but we know little about chemistry of the 61st element, promethium (Pm), a lanthanide that is highly radioactive and inaccessible. Despite its importance, Pm has been conspicuously absent from the experimental studies of lanthanides, impeding our full comprehension of the so-called lanthanide contraction phenomenon: a fundamental aspect of the periodic table that is quoted in general chemistry textbooks. Here we demonstrate a stable chelation of the Pm radionuclide (half-life of 2.
View Article and Find Full Text PDFDalton Trans
August 2024
Department of Chemistry & Biochemistry, School of Green Chemistry and Engineering, College of Natural Sciences and Mathematics, The University of Toledo, 2801 W. Bancroft St. MS 602, Toledo, Ohio 43606-3390, USA.
This perspective summarizes our group's extensive research in the realm of organometallic lanthanide complexes, while also placing the catalytic reactions supported by these species within the context of known lanthanide catalysis worldwide, with a specific focus on phosphorus-based catalytic reactions such as intermolecular hydrophosphination and hydrophosphinylation. α-Metalated ,-dimethylbenzylamine ligands have been utilized to generate homoleptic lanthanide complexes, which have subsequently proven to be highly active lanthanum-based catalysts. The main goal of our research program has been to enhance the catalytic efficiency of lanthanum-based complexes, which began with initial successes in the stoichiometric synthesis of organometallic lanthanide complexes and utilization of these species in catalytic hydrophosphination reactions.
View Article and Find Full Text PDFInorg Chem
May 2024
Institut für Anorganische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
Homoleptic tetramethylaluminates Ln(AlMe) react with KTp (Tp = tris(3-Bu-5-Me-pyrazolyl)borato) to yield rare-earth-metal methylidene complexes (Tp)Ln(μ-CH)[(μ-Me)AlMe] (Ln = La, Ce, Nd). The lanthanum reaction is prone to additional C-H- and B-N-bond activation, affording coproducts La[HB(pz)(pz)][(μ-CH)(μ-Me)AlMe] and [La(μ-pz)(AlMe)] (pz = 3-Bu-5-Me-pyrazolato). The protonolysis reaction of Ln(AlMe) and Hpz provides more efficient access to [Ln(μ-pz)(AlMe)] (Ln = La, Nd).
View Article and Find Full Text PDFInorg Chem
May 2024
Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States.
A family of rare-earth complexes [RE(III) = Y, La, Gd, Tb, Dy, and Er] with doubly reduced dibenzo[,]cyclooctatetraene (DBCOT) has been synthesized and structurally characterized. X-ray diffraction analysis confirms that all products of the [RE(DBCOT)(THF)][RE(DBCOT)] composition consist of the anionic sandwich [RE(DBCOT)] and the cationic counterpart [RE(DBCOT)(THF)]. Within the sandwich, two elongated π decks are slightly bent toward the metal center (avg.
View Article and Find Full Text PDFInorg Chem
May 2024
Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States.
The development of catalysts for stereospecific polymerization of 1,3-dienes is an area of interest due to the robust nature of poly(1,3-diene)s' physical and mechanical properties, as well as the material's versatility in many applications. Dialkyl rare earth metal complexes supported by a diverse cast of ligand frameworks are selective for the polymerization of 1,3-dienes and are an exciting option for examination. However, development in this area has been hampered by the focus on complex catalyst systems that are costly to make.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!