Deaggregation of Zinc Dihydride by Lewis Acids Including Carbon Dioxide in the Presence of Nitrogen Donors

Autor: Thomas P. Spaniol, Jun Okuda, Karl N. McCabe, Laurent Maron, Louis J. Morris, Florian Ritter
Přispěvatelé: Institute of Inorganic Chemistry [Aachen] (IAC RWTH), Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Deutsche Forschungsgemeinschaft, Alexander von Humboldt foundation
Rok vydání: 2021
Předmět:
Zdroj: Inorganic Chemistry
Inorganic Chemistry, 2021, 60 (20), pp.15583-15592. ⟨10.1021/acs.inorgchem.1c02207⟩
ISSN: 1520-510X
0020-1669
DOI: 10.1021/acs.inorgchem.1c02207⟩
Popis: International audience; Thermally sensitive polymeric zinc dihydride [ZnH2] (n) can conveniently be prepared by the reaction of ZnEt2 with [AlH3(NEt3)]. When reacted with CO2 (1 bar) in the presence of chelating N-donor ligands L-n = N,N,N',N'tetramethylethylenediamine (TMEDA), N,N,N',N'-tetramethyl-1,3-propanediamine (TMPDA), N,N,N',N.,N''-pentamethyldiethylenetriamine (PMDTA), and 1,4,7,10tetramethyl-1,4,7,10-tetraazacyclododecane (Me(4)TACD), insertion into the Zn-H bond readily occurred. Depending on the denticity n, formates [(L-n)Zn(OCHO)(2)] were isolated and structurally characterized, either as a molecule (L-n = TMEDA, TMPDA, PMDTA) or a charge-separated ion pair [(L-n)Zn(OCHO)][OCHO] (L-n = Me(4)TACD). The reaction of [ZnH2] n with the mild Lewis acid BPh3 in the presence of chelating N-donor ligands L-n gave a series of hydridotriphenylborates, either as a contact ion pair [(L-2)Zn(H)(HBPh3)] (L-2 = TMEDA, TMPDA) or a separated ion pair [(L-n)Zn(H)][HBPh3] (L-n = PMDTA, Me(4)TACD). In the crystal, the contact ion pair [(TMEDA)Zn(H)(HBPh3)] showed a bent Zn-H-B bridge indicative of a delocalized Zn-H-B interaction. In contrast, a linear Zn-H-B bridge for [(TMPDA)Zn(H)(HBPh3)] was observed, suggesting a contact ion pair. In THF solution, both complexes show an exchange with free BPh3 as well as [HBPh3](-). DFT calculations suggest the presence of [HBPh3](-) anion with a highly polarized B-H bond that interacts with the Lewis acidic zinc hydride cation [(L-2)Zn(H)](+). The hydridotriphenylborates [(L-n)Zn(H)(HBPh3)] underwent CO2 insertion to give (formato)zinc (formoxy)triphenylborate complexes [(L-n)Zn(OCHO)][(OCHO)BPh3] (L-n = TMPDA, PMDTA, Me(4)TACD). For L-n = TMEDA, a dinuclear complex [(L-n)(2)Zn-2(mu-OCHO)(3)][(OCHO)BPh3] was isolated. Hydridotriphenylborates [(L-n)Zn(H)(HBPh3)] catalyzed the hydrosilylation of CO2 (1 bar) by (BuMe2SiH)-Bu-n in THF at 70 degrees C to give formoxysilane and (methoxy)silane.
Databáze: OpenAIRE
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