Proton‐Induced Change of the Coordination Mode of a Boron Group: Boryl Complexes [Mn(CO)₄(PR₃)(BH₂⋅PMe₃)] and Cationic Borane σ Complexes [Mn(CO)₄(PR₃)(η¹‐BH₃⋅PMe₃)]⁺

Abstract

Koordinationswechsel bei Protonierung: Die Borylmangankomplexe 1 reagieren unter Protonierung zu den kationischen Boran‐σ‐Komplexen 2. Die Zersetzung von 2 verläuft unter heterolytischer Spaltung der Metall‐koordinierten B‐H‐Bindung.

Investigation of the Stability of the M‐H‐B Bond in Borane σ Complexes [M(CO)5(η1‐BH2R⋅L)] and [CpMn(CO)2(η1‐BH2R⋅L)] (M=Cr, W; L=Tertiary Amine or Phosphine): Substituent and Lewis Base Effects

“…In similar manners, [Cr(CO) 6 ] or [W(CO) 6 ] was irradiated with a 1:1 mixture of BH 3 ·PMe 3 and various monosubstitut- (5) 1.843(2) C(1)ÀO (1) 1.138(2) C(2)ÀO (2) 1.133(3) C(3)ÀO (3) 1.138(3) C(4)ÀO (4) 1.139(3) C(5)ÀO (5) 1.154 (3) Nonbonding distances C(3)···C (14) 3.678(3) C(3)···H (14) 3.058 (2) Bond angles (5) 1.839(3) C(1)ÀO (1) 1.130(3) C(2)ÀO (2) 1.129(4) C(3)ÀO (3) 1.135(4) C(4)ÀO (4) 1.135 (4) C (5) Bond angles…”

“…6 - [c] À2.88 - 6 ]benzene produced a yellow solution. This solution contained 1 c and 1 d, the latter of which was more abundant as evidenced by NMR spectroscopy.…”

“…When [Cr(CO) 6 ] is irradiated with SiHR 3 , silane adducts [Cr(CO) 5 A C H T U N G T R E N N U N G (HSiR 3 )] are generated. Although this species is unstable, it can be observed by NMR at low temperature.…”

“…During the course of study, we have synthesized borane s complexes [M(CO) 5 A C H T U N G T R E N N U N G (h 1 -BH 3 ·L)] (M = Cr, W; L = PMe 3 , PPh 3 , NMe 3 ), [3,4] [CpMn(CO) 2 A C H T U N G T R E N N U N G (h 1 -BH 3 ·L)] (L = PMe 3 , NMe 3 ), [5] and related compounds. [6,7] Transition-metal s complexes, in which an E À H s bond (E = main group element) acts as a two-electron donor, have been of interest from the bonding-and structure-point of view. [13] Complexation of a s bond with a metal center is thought to consist of the electron donation from the EÀH bonding s orbital into a vacant metal d s orbital as well as the back-donation from a filled d p orbital to the E-H antibonding s* orbital (Scheme 1).…”

Ruthenium Bidentate Phosphine Complexes for the Coordination and Catalytic Dehydrogenation of Amine– and Phosphine–Boranes

“…Whereas the coordination of phosphine-borane to transition-metal centres through an h 1 -HÀB interaction is well-established, [7,8,12] subsequent PÀB cleavage to generate a (secondary) phosphine-metal complex has not, to the best of our knowledge, been observed before. Most commonly, intact H 3 B·PR 3 ligands can simply be displaced from a metal, for example, by addition of a Lewis base (CO, MeCN).…”