Metallaboratranes Derived from a Triphosphanyl–Borane: Intrinsic C₃ Symmetry Supported by a Z‐Type Ligand

Abstract

Symmetry from within: Coordination of a triphosphanyl–borane ligand to gold(I) and platinum(0) affords metallaboratranes exhibiting C3 symmetry both in solution and in the solid state. Such a helical geometry is supported by axial M→B dative interactions and results from the envelope conformations of the PCCBM metallacycles.

σ-Acceptor, Z-type ligands for transition metals

“…DPB readily displaced the labile thioether ligand of [AuCl(SMe 2 )] to give the air-stable complex [(DPB)AuCl] (Scheme 5). 90 The ensuing complex adopts a trigonal-bipyramidal cage structure that is reminiscent to that observed in the tris(methimazolyl)metallaboratranes, with the noticeable difference that all PCCBAu metallacycles adopt envelop conformations so that the complex exhibits an original (Table 4). The X-ray diffraction analysis revealed a tetracoordinate square-planar arrangement around gold, with the boron atom trans to chlorine (see section 5.1).…”

“…In contrast, the association of an L-type ligand commonly provokes a substantial pyramidalization. 90 Also noticeable is the chiral three-bladed propeller arrangement displayed by this cage complex, and by all the group 10 and 11 metallaboratranes derived from TPB. 29 Although most complexes featuring M -Z interactions adopt classical geometries, some noticeable exceptions exist.…”

An Efficient Method for the Synthesis of Boratrane Complexes of Late Transition Metals

“…The structures of compounds 6 and 7 are similar to that of 5 . Although the Ir→B bond distance of 2.136(13) Å is comparable to those in reported iridaboratranes,– the Rh→B distance of 2.12(3) Å is somewhat shorter than those in reported boratrane complexes of rhodium (see Table ) …”

“…In 2008, Bourissou introduced a triphenylphosphine borane and studied its coordination to Group 10 and 11 metals, which led to a series of metallaboratrane species . For example, treatment of [AuCl(SMe 2 )] with triphosphanyl borane (TPB; [ o‐i Pr 2 P(C 6 H 4 )] 3 B) yielded a gold(I) metallaboratrane complex [Au{B( i Pr 2 PC 6 H 4 ) 3 }Cl] with a dative Au→B interaction …”

Coordination Chemistry of Neutral (Ln)–Z Amphoteric and Ambiphilic Ligands

“…Even in the presence of a rigid framework, the compounds [o-(iPr 2 P)C 6 3 B}Pt] (8), respectively, where the three phosphane moieties and the boron acceptor bind the metal centre with C 3 symmetry. [26] Complex 7 adopts a trigonal-bipyramidal geometry, where one of the axial positions is occupied by a boron atom. The short Au-B bond length of 2.318(8) Å, the pyramidalization of the boron (ΣB α = 339.3°) and the upfield 11 B NMR chemical shift (δ = 27.7 ppm), as compared to the 60-80 ppm range usually observed for triarylboranes, are good indications of a AuǞB dative interaction.…”