Heteroleptic Heavier Alkaline Earth Metal Amide Complexes Stabilized by a Superbulky β-Diketiminate Ligand

Gentner T, Rösch B, Thum K, Langer J, Ballmann G, Pahl J, Donaubauer W, Hampel F, Harder S (2019)

Publication Type: Journal article

Publication year: 2019

Journal

Organometallics American Chemical Society

Book Volume: 38

Pages Range: 2485-2493

Journal Issue: 12

DOI: 10.1021/acs.organomet.9b00211

Abstract

Heteroleptic alkaline earth metal (Ae = Ca, Sr, Ba) amide complexes with the superbulky β-diketiminate ligand DIPePBDI (CH[C(Me)N-DIPeP]2, DIPeP = 2,6-di-iso-pentylphenyl) have been prepared by direct deprotonation of DIPePBDI-H with either AeN′′2 or AeN′′2·(THF)2 (N′′ = N(SiMe3)2). Despite long reaction times of 5-14 days, this convenient one-step synthetic method has the major advantage that metal-pure products are obtained in generally quantitative yields. All (DIPePBDI)AeN′′ and (DIPePBDI)AeN′′·THF complexes are monomeric and stabilized by agostic metal···Me3Si and metal···iso-pentyl interactions. They are highly soluble in toluene and indefinitely stable toward ligand scrambling, even after 2 weeks at 140 °C. The same series with the smaller DIPPBDI ligand (CH[C(Me)N-DIPP]2, DIPP = 2,6-di-iso-propylphenyl) could, except for Ca, also be prepared by direct ligand deprotonation. The (DIPPBDI)CaN′′ and (DIPPBDI)CaN′′·THF complexes are stable toward ligand exchange up to 110 °C. Whereas THF-free (DIPPBDI)SrN′′ and (DIPPBDI)BaN′′ decompose at 50 and 20 °C, respectively, their THF adducts were found to be stable up to 60 °C. This is, however, strongly dependent on complex purity. Slight hydrolysis or contamination with KN′′ accelerates ligand scrambling. Therefore, partial hydrolysis and salt metathesis routes that involve KN′′ should be avoided when synthesizing heteroleptic complexes of the heavier Ae metals.

Authors with CRIS profile

Thomas Gentner Lehrstuhl für Anorganische und Metallorganische Chemie Bastian Rösch Lehrstuhl für Anorganische und Metallorganische Chemie Katharina Thum Lehrstuhl für Anorganische und Metallorganische Chemie Jens Langer Lehrstuhl für Anorganische und Metallorganische Chemie Gerd Ballmann Lehrstuhl für Anorganische und Metallorganische Chemie Jürgen Pahl Lehrstuhl für Anorganische und Metallorganische Chemie Wolfgang Donaubauer Lehrstuhl für Organische Chemie I Frank Hampel Lehrstuhl für Organische Chemie I Sjoerd Harder Lehrstuhl für Anorganische und Metallorganische Chemie

How to cite

APA:

Gentner, T., Rösch, B., Thum, K., Langer, J., Ballmann, G., Pahl, J.,... Harder, S. (2019). Heteroleptic Heavier Alkaline Earth Metal Amide Complexes Stabilized by a Superbulky β-Diketiminate Ligand. Organometallics, 38(12), 2485-2493. https://dx.doi.org/10.1021/acs.organomet.9b00211

MLA:

Gentner, Thomas, et al. "Heteroleptic Heavier Alkaline Earth Metal Amide Complexes Stabilized by a Superbulky β-Diketiminate Ligand." Organometallics 38.12 (2019): 2485-2493.

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