Stable formally zerovalent and diamagnetic monovalent niobium and tantalum complexes based on diazadiene ligands.
This paper describes the efficient synthesis and full characterization of rare formally zerovalent and diamagnetic monovalent pseudooctahedral niobium and tantalum complexes. The reaction of NbCl(4)(thf)(2) with 4 equiv of Na and 3.5 equiv of iPr(2)-dad (1,4-diisopropyl-1,4-diaza-1,3-diene) yields N...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
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2002
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| _version_ | 1797073176015929344 |
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| author | Daff, P Etienne, M Donnadieu, B Knottenbelt, S McGrady, J |
| author_facet | Daff, P Etienne, M Donnadieu, B Knottenbelt, S McGrady, J |
| author_sort | Daff, P |
| collection | OXFORD |
| description | This paper describes the efficient synthesis and full characterization of rare formally zerovalent and diamagnetic monovalent pseudooctahedral niobium and tantalum complexes. The reaction of NbCl(4)(thf)(2) with 4 equiv of Na and 3.5 equiv of iPr(2)-dad (1,4-diisopropyl-1,4-diaza-1,3-diene) yields Nb(iPr(2)-dad)(3) in 52% yield. Ta(iPr(2)-dad)(3) is also obtained in 33% yield from 5 equiv of Na/naphthalene and 3.5 equiv of iPr(2)-dad. Oxidation of these complexes with AgBPh(4) yields the diamagnetic complexes [M(iPr(2)-dad)(3)][BPh(4)] (M = Nb, Ta). X-ray and spectroscopic data indicate that the unpaired electron density is localized on the ligands. DFT calculations reveal that, in the prevailing D(3) symmetry, a very strong splitting of t(2g) metal-based orbitals occurs, leading to the diamagnetism of the 16e M(iPr(2)-dad)(3)(+). This strong splitting allows a M-N nonbonding, ligand-based orbital to accommodate additional electrons, as a result of which the formally zerovalent complexes, M(iPr(2)-dad)(3), are in fact correctly formulated as M(+)iPr(2)-dad (-), that is, (16e + 1e). |
| first_indexed | 2024-03-06T23:18:18Z |
| format | Journal article |
| id | oxford-uuid:67e2b99c-270f-4141-b5a1-844e7f495bb9 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T23:18:18Z |
| publishDate | 2002 |
| record_format | dspace |
| spelling | oxford-uuid:67e2b99c-270f-4141-b5a1-844e7f495bb92022-03-26T18:41:15ZStable formally zerovalent and diamagnetic monovalent niobium and tantalum complexes based on diazadiene ligands.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:67e2b99c-270f-4141-b5a1-844e7f495bb9EnglishSymplectic Elements at Oxford2002Daff, PEtienne, MDonnadieu, BKnottenbelt, SMcGrady, JThis paper describes the efficient synthesis and full characterization of rare formally zerovalent and diamagnetic monovalent pseudooctahedral niobium and tantalum complexes. The reaction of NbCl(4)(thf)(2) with 4 equiv of Na and 3.5 equiv of iPr(2)-dad (1,4-diisopropyl-1,4-diaza-1,3-diene) yields Nb(iPr(2)-dad)(3) in 52% yield. Ta(iPr(2)-dad)(3) is also obtained in 33% yield from 5 equiv of Na/naphthalene and 3.5 equiv of iPr(2)-dad. Oxidation of these complexes with AgBPh(4) yields the diamagnetic complexes [M(iPr(2)-dad)(3)][BPh(4)] (M = Nb, Ta). X-ray and spectroscopic data indicate that the unpaired electron density is localized on the ligands. DFT calculations reveal that, in the prevailing D(3) symmetry, a very strong splitting of t(2g) metal-based orbitals occurs, leading to the diamagnetism of the 16e M(iPr(2)-dad)(3)(+). This strong splitting allows a M-N nonbonding, ligand-based orbital to accommodate additional electrons, as a result of which the formally zerovalent complexes, M(iPr(2)-dad)(3), are in fact correctly formulated as M(+)iPr(2)-dad (-), that is, (16e + 1e). |
| spellingShingle | Daff, P Etienne, M Donnadieu, B Knottenbelt, S McGrady, J Stable formally zerovalent and diamagnetic monovalent niobium and tantalum complexes based on diazadiene ligands. |
| title | Stable formally zerovalent and diamagnetic monovalent niobium and tantalum complexes based on diazadiene ligands. |
| title_full | Stable formally zerovalent and diamagnetic monovalent niobium and tantalum complexes based on diazadiene ligands. |
| title_fullStr | Stable formally zerovalent and diamagnetic monovalent niobium and tantalum complexes based on diazadiene ligands. |
| title_full_unstemmed | Stable formally zerovalent and diamagnetic monovalent niobium and tantalum complexes based on diazadiene ligands. |
| title_short | Stable formally zerovalent and diamagnetic monovalent niobium and tantalum complexes based on diazadiene ligands. |
| title_sort | stable formally zerovalent and diamagnetic monovalent niobium and tantalum complexes based on diazadiene ligands |
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