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Wedal JC, Anderson-Sanchez LM, Dumas MT, Gould CA, Beltrán-Leiva MJ, Celis-Barros C, Páez-Hernández D, Ziller JW, Long JR, Evans WJ. Synthesis and Crystallographic Characterization of a Reduced Bimetallic Yttrium ansa-Metallocene Hydride Complex, [K(crypt)][(μ-Cp An)Y(μ-H)] 2 (Cp An = Me 2Si[C 5H 3(SiMe 3)-3] 2), with a 3.4 Å Yttrium-Yttrium Distance. J Am Chem Soc 2023; 145:10730-10742. [PMID: 37133919 DOI: 10.1021/jacs.3c01405] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The reduction of a bimetallic yttrium ansa-metallocene hydride was examined to explore the possible formation of Y-Y bonds with 4d1 Y(II) ions. The precursor [CpAnY(μ-H)(THF)]2 (CpAn = Me2Si[C5H3(SiMe3)-3]2) was synthesized by hydrogenolysis of the allyl complex CpAnY(η3-C3H5)(THF), which was prepared from (C3H5)MgCl and [CpAnY(μ-Cl)]2. Treatment of [CpAnY(μ-H)(THF)]2 with excess KC8 in the presence of one equivalent of 2.2.2-cryptand (crypt) generates an intensely colored red-brown product crystallographically identified as [K(crypt)][(μ-CpAn)Y(μ-H)]2. The two rings of each CpAn ligand in the reduced anion [(μ-CpAn)Y(μ-H)]21- are attached to two yttrium centers in a "flyover" configuration. The 3.3992(6) and 3.4022(7) Å Y···Y distances between the equivalent metal centers within two crystallographically independent complexes are the shortest Y···Y distances observed to date. Ultraviolet-visible (UV-visible)/near infrared (IR) and electron paramagnetic resonance (EPR) spectroscopy support the presence of Y(II), and theoretical analysis describes the singly occupied molecular orbital (SOMO) as an Y-Y bonding orbital composed of metal 4d orbitals mixed with metallocene ligand orbitals. A dysprosium analogue, [K(18-crown-6)(THF)2][(μ-CpAn)Dy(μ-H)]2, was also synthesized, crystallographically characterized, and studied by variable temperature magnetic susceptibility. The magnetic data are best modeled with the presence of one 4f9 Dy(III) center and one 4f9(5dz2)1 Dy(II) center with no coupling between them. CASSCF calculations are consistent with magnetic measurements supporting the absence of coupling between the Dy centers.
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Affiliation(s)
- Justin C Wedal
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | | | - Megan T Dumas
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Colin A Gould
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - María J Beltrán-Leiva
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Cristian Celis-Barros
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Dayán Páez-Hernández
- Center of Applied Nanoscience (CANS), Universidad Andres Bello, Santiago 8370146, Chile
| | - Joseph W Ziller
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Jeffrey R Long
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - William J Evans
- Department of Chemistry, University of California, Irvine, California 92697, United States
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