Bis(imino)carbazolate: A Master Key for Barium Chemistry

Abstract

Reported here is ar eadily available bis-(imino)carbazole-based proligand that constitutes aconvenient entry point into the challenging synthetic molecular chemistry of barium. It enables the preparation of rare or even, up to now, unknown, solution-stable heteroleptic barium complexes.T he syntheses and structural features for the first molecular barium fluoride and the first barium stannylide,w ith an unsupported BaÀSn bond, are described, along with other carbazolate barium species:a na mide (both ar emarkably stable starting material and an excellent hydrophosphination precatalyst), iodide,and silanylide.DFT analysis of bonding patterns in the barium stannylide and barium silanylide highlights ap revailingly ionic barium-tetrelide bond with as mall covalent contribution.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Contemporary Molecular Barium Chemistry

“…Syntheses of the heteroleptic complexes [{BDI DiPeP }BaN(SiMe 3 ) 2 · (thf) x ] (x = 0 or 1), [{DPM Anth }BaN(SiMe 3 ) 2 ], [{CH(Ph 2 P=N‐SiMe 3 ) 2 }Ba(µ‐I) · (thf) 2 ] 2 [98b] and complexes supported by the bis(imino)carbozate {Carb DiPP } – …”

“…It has recently been reported that a bis(imino)carbazolate ligand {Carb DiPP } – has been used to stabilize a broad range of heteroleptic barium species including the first fluoride, silanide and stannylide species . The four‐coordinate heteroleptic barium amide [{Carb DiPP }BaN(SiMe 3 ) 2 ] was synthesized in 92 % yield from the protonolysis between {Carb DiPP }H and [Ba{µ‐N(SiMe 3 ) 2 }{N(SiMe 3 ) 2 }] 2 .…”

Bonding in Barium Boryloxides, Siloxides, Phenoxides and Silazides: A Comparison with the Lighter Alkaline Earths

“…Stopping these phenomena, which are most troublesome for the largest and most electropositive element barium, still constitutes a challenge in modern alkaline‐earth molecular chemistry. Yet, thanks to the use of carefully devised ligands, for example β‐diketiminates, [12,32] iminoanilides, [12] carbazolates, [33–34] phenoxides, [6,35–36] or tris(pyrazolyl)borates, [37] the number of stable, heteroleptic barium complexes has been growing steadily in recent years. Beyond homogenous catalysis, these ligands have led to breakthroughs such as the recent preparation of soluble barium‐hydrides [31,37–38] …”

Synthesis and reactivity of alkaline-earth stannanide complexes by hydride-mediated distannane metathesis and organostannane dehydrogenation

“…Compound 5 was readily prepared by the oxidative-addition of hexamethyldistannane to calcium metal, 43 the synthesis of 6 and 7 utilised salt metathesis routes from group 1-metallated precursors. [44][45][46] Neither of these strategies, however, is likely to be amenable to incorporation into catalytic cycles. Since the formation of 3 and 4 is redox neutral at calcium and generates H 2 instead of insoluble salts as a by-product, therefore, it holds attractive potential for the development of Ae-based catalysts for processes such as hydrostannylation or stannane dehydrocoupling.…”