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Zgrabik J, Bhowmick R, Eckstrom FD, Harrison AR, Fetrow TV, Blake AV, Vlaisavljevich B, Daly SR. The Influence of Phosphorus Substituents on the Structures and Solution Speciation of Trivalent Uranium and Lanthanide Phosphinodiboranates. Inorg Chem 2024; 63:9451-9463. [PMID: 38011639 PMCID: PMC11134491 DOI: 10.1021/acs.inorgchem.3c02773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/29/2023]
Abstract
Here, we report the mechanochemical synthesis and characterization of homoleptic uranium and lanthanide phosphinodiboranates with isopropyl and ethyl substituents attached to phosphorus. M(H3BPiPr2BH3)3 complexes with M = U, Nd, Sm, Tb, and Er were prepared by ball milling UI3(THF)4, SmBr3, or MI3 with three equivalents of K(H3BPiPr2BH3). M(H3BPEt2BH3)3 with M = U and Nd were prepared similarly using K(H3BPEt2BH3), and the complexes were purified by extraction and crystallization from Et2O or CH2Cl2. Single-crystal XRD studies revealed that all five M(H3BPiPr2BH3)3 crystallize as dimers, despite the significant differences in metal radii across the series. In contrast, Nd(H3BPEt2BH3)3 with smaller ethyl substituents crystallized as a coordination polymer. Crystals of U(H3BPEt2BH3)3 were not suitable for structural analysis, but crystals of U(H3BPMe2BH3)3 isolated in low yield by solution methods were isostructural with Nd(H3BPEt2BH3)3. 1H and 11B NMR studies in C6D6 revealed that all of the complexes form mixtures of monomer and oligomers when dissolved, and the extent of oligomerization was highly dependent on metal radius and phosphorus substituent size. A comprehensive analysis of all structurally characterized uranium and lanthanide phosphinodiboranate complexes reported to date, including those with larger Ph and tBu substituents, revealed that the degree of oligomerization in solution can be correlated to differences in B-P-B angles obtained from single-crystal XRD studies. Density functional theory calculations, which included structural optimizations in combination with conformational searches using tight binding methods, replicated the general experimental trends and revealed free energy differences that account for the different solution and solid-state structures. Collectively, these results reveal how steric changes to phosphorus substituents significantly removed from metal coordination sites can have a significant influence on solution speciation, deoligomerization energies, and the solid-state structure of homoleptic phosphinodiboranate complexes containing trivalent f-metals.
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Affiliation(s)
- Joshua
C. Zgrabik
- Department
of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Rina Bhowmick
- Department
of Chemistry, The University of South Dakota, 414 E Clark St., Vermillion, South Dakota 57069, United States
| | - Francesca D. Eckstrom
- Department
of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - A. Rayford Harrison
- Department
of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Taylor V. Fetrow
- Department
of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Anastasia V. Blake
- Department
of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Bess Vlaisavljevich
- Department
of Chemistry, The University of South Dakota, 414 E Clark St., Vermillion, South Dakota 57069, United States
| | - Scott R. Daly
- Department
of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
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Fetrow TV, Daly SR. Mechanochemical synthesis and structural analysis of trivalent lanthanide and uranium diphenylphosphinodiboranates. Dalton Trans 2021; 50:11472-11484. [PMID: 34346459 DOI: 10.1039/d1dt01932e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Phosphinodiboranates (H3BPR2BH3-) are a class of borohydrides that have merited a reputation as weakly coordinating anions, which is attributed in part to the dearth of coordination complexes known with transition metals, lanthanides, and actinides. We recently reported how K(H3BPtBu2BH3) exhibits sluggish salt elimination reactivity with f-metal halides in organic solvents such as Et2O and THF. Here we report how this reactivity appears to be further attenuated in solution when the tBu groups attached to phosphorus are exchanged for R = Ph or H, and we describe how mechanochemistry was used to overcome limited solution reactivity with K(H3BPPh2BH3). Grinding three equivalents of K(H3BPPh2BH3) with UI3(THF)4 or LnI3 (Ln = Ce, Pr, Nd) allowed homoleptic complexes with the empirical formulas U(H3BPPh2BH3)3 (1), Ce(H3BPPh2BH3)3 (2), Pr(H3BPPh2BH3)3 (3), and Nd(H3BPPh2BH3)3 (4) to be prepared and subsequently crystallized in good yields (50-80%). Single-crystal XRD studies revealed that all four complexes exist as dimers or coordination polymers in the solid-state, whereas 1H and 11B NMR spectra showed that they exist as a mixture of monomers and dimers in solution. Treating 4 with THF breaks up the dimer to yield the monomeric complex Nd(H3BPPh2BH3)3(THF)3 (4-THF). XRD studies revealed that 4-THF has one chelating and two dangling H3BPPh2BH3- ligands bound to the metal to accommodate binding of THF. In contrast to the results with K(H3BPPh2BH3), attempting the same mechanochemical reactions with Na(H3BPH2BH3) containing the simplest phosphinodiboranate were unsuccessful; only the partial metathesis product U(H3BPH2BH3)I2(THF)3 (5) was isolated in poor yields. Despite these limitations, our results offer new examples showing how mechanochemistry can be used to rapidly synthesize molecular coordination complexes that are otherwise difficult to prepare using more traditional solution methods.
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Affiliation(s)
- Taylor V Fetrow
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, USA.
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Izod K, Watson JM, Harrington RW, Clegg W. Phosphido-bis(borane) complexes of the alkaline earth metals. Dalton Trans 2021; 50:1019-1024. [DOI: 10.1039/d0dt03895d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The phosphido-bis(borane) complexes 2–4 crystallise with remarkably similar structures, in spite of the progressively increasing ionic radii of the metal centres.
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Affiliation(s)
- Keith Izod
- Main Group Chemistry Laboratories
- School of Chemistry
- Newcastle University
- Newcastle upon Tyne
- UK
| | - James M. Watson
- Main Group Chemistry Laboratories
- School of Chemistry
- Newcastle University
- Newcastle upon Tyne
- UK
| | - Ross W. Harrington
- Main Group Chemistry Laboratories
- School of Chemistry
- Newcastle University
- Newcastle upon Tyne
- UK
| | - William Clegg
- Main Group Chemistry Laboratories
- School of Chemistry
- Newcastle University
- Newcastle upon Tyne
- UK
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Morris LJ, Hill MS, Mahon MF, Manners I, Patrick BO. Alkaline-Earth Derivatives of Diphenylphosphine–Borane. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Louis J. Morris
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Michael S. Hill
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Mary F. Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Ian Manners
- Department of Chemistry, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Brian O. Patrick
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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Fetrow TV, Bhowmick R, Achazi AJ, Blake AV, Eckstrom FD, Vlaisavljevich B, Daly SR. Chelating Borohydrides for Lanthanides and Actinides: Structures, Mechanochemistry, and Case Studies with Phosphinodiboranates. Inorg Chem 2019; 59:48-61. [DOI: 10.1021/acs.inorgchem.9b01628] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Taylor V. Fetrow
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Rina Bhowmick
- Department of Chemistry, The University of South Dakota, 414 East Clark Street, Vermillion, South Dakota 57069, United States
| | - Andreas J. Achazi
- Department of Chemistry, The University of South Dakota, 414 East Clark Street, Vermillion, South Dakota 57069, United States
| | - Anastasia V. Blake
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Francesca D. Eckstrom
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Bess Vlaisavljevich
- Department of Chemistry, The University of South Dakota, 414 East Clark Street, Vermillion, South Dakota 57069, United States
| | - Scott R. Daly
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
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Blake AV, Fetrow TV, Theiler ZJ, Vlaisavljevich B, Daly SR. Homoleptic uranium and lanthanide phosphinodiboranates. Chem Commun (Camb) 2018; 54:5602-5605. [DOI: 10.1039/c8cc02862a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis and structures of a new class of homoleptic f-metal borohydride complexes (phosphinodiboranates) are described with U, Nd, and Er.
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Affiliation(s)
| | | | | | | | - Scott R. Daly
- Department of Chemistry
- The University of Iowa
- Iowa City
- USA
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Marquardt C, Kahoun T, Stauber A, Balázs G, Bodensteiner M, Timoshkin AY, Scheer M. Anionische Ketten der Stammverbindungen der Pnictogenylborane. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201608875] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Christian Marquardt
- Universität Regensburg; Institut für Anorganische Chemie; 93040 Regensburg Deutschland
| | - Tobias Kahoun
- Universität Regensburg; Institut für Anorganische Chemie; 93040 Regensburg Deutschland
| | - Andreas Stauber
- Universität Regensburg; Institut für Anorganische Chemie; 93040 Regensburg Deutschland
| | - Gábor Balázs
- Universität Regensburg; Institut für Anorganische Chemie; 93040 Regensburg Deutschland
| | - Michael Bodensteiner
- Universität Regensburg; Institut für Anorganische Chemie; 93040 Regensburg Deutschland
| | - Alexey Y. Timoshkin
- Institute of Chemistry; St. Petersburg State University; Universitetskaya nab. 7/9 199034 St. Petersburg Russland
| | - Manfred Scheer
- Universität Regensburg; Institut für Anorganische Chemie; 93040 Regensburg Deutschland
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Marquardt C, Kahoun T, Stauber A, Balázs G, Bodensteiner M, Timoshkin AY, Scheer M. Anionic Chains of Parent Pnictogenylboranes. Angew Chem Int Ed Engl 2016; 55:14828-14832. [DOI: 10.1002/anie.201608875] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Christian Marquardt
- Universität Regensburg Institut für Anorganische Chemie 93040 Regensburg Germany
| | - Tobias Kahoun
- Universität Regensburg Institut für Anorganische Chemie 93040 Regensburg Germany
| | - Andreas Stauber
- Universität Regensburg Institut für Anorganische Chemie 93040 Regensburg Germany
| | - Gábor Balázs
- Universität Regensburg Institut für Anorganische Chemie 93040 Regensburg Germany
| | - Michael Bodensteiner
- Universität Regensburg Institut für Anorganische Chemie 93040 Regensburg Germany
| | - Alexey Y. Timoshkin
- Institute of Chemistry St. Petersburg State University Universitetskaya nab. 7/9 199034 St. Petersburg Russia
| | - Manfred Scheer
- Universität Regensburg Institut für Anorganische Chemie 93040 Regensburg Germany
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Wagner LK, Majzoub EH, Allendorf MD, Grossman JC. Tuning metal hydride thermodynamics via size and composition: Li–H, Mg–H, Al–H, and Mg–Al–H nanoclusters for hydrogen storage. Phys Chem Chem Phys 2012; 14:6611-6. [DOI: 10.1039/c2cp24063g] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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