Gallium Hydrides with a Radical-Anionic Ligand

Abstract

The reaction of ClGaH with a sodium salt of the dpp-Bian radical-anion (dpp-Bian)Na (dpp-Bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) affords paramagnetic gallane (dpp-Bian)Ga(Cl)H (1). Oxidation of (dpp-Bian)Ga-Ga(dpp-Bian) (2) with NO results in the dimeric oxide (dpp-Bian)Ga(μ-O)Ga(dpp-Bian) (3). A treatment of the oxide 3 with phenylsilane affords paramagnetic gallium hydrides (dpp-Bian)GaH (4) and (dpp-Bian)Ga{OSi(Ph)H}H (5) depending on the reagent's stoichiometry. The reaction of digallane 2 with benzaldehyde produces pinacolate (dpp-Bian)Ga(OCHPh) (6). In the presence of PhSiH, the reaction between digallane 2 and benzaldehyde (2: PhSiH: PhC(H)O = 1:4:4) affords compound 4. The newly prepared complexes 1, 3-6 consist of a spin-labeled diimine ligand-dpp-Bian radical-anion. The presence of the ligand-localized unpaired electron allows the use of the ESR spectroscopy for characterization of the gallium hydrides reported. The molecular structures of compounds 1, 3-6 have been determined by the single-crystal X-ray analysis.

Gallium “Shears” for C=N and C=O Bonds of Isocyanates

“…[40] Cleavage of the C=Od ouble bond of an isocyanate by ad igermyne [LGeÀGeL] (L = N(Ar*)(SiMe 3 ), Ar* = C 6 H 2 {C(H)Ph 2 } 2 Me-2,6,4) to give the bis(germylene)o xide compound [Ar*GeOGeAr*] has also been documented. [40] Cleavage of the C=Od ouble bond of an isocyanate by ad igermyne [LGeÀGeL] (L = N(Ar*)(SiMe 3 ), Ar* = C 6 H 2 {C(H)Ph 2 } 2 Me-2,6,4) to give the bis(germylene)o xide compound [Ar*GeOGeAr*] has also been documented.…”

“…The adduct [L 1 Ga-(m-O) 2 -GaL 1 ]h as been reported previously. [40] Cleavage of the C=Od ouble bond of an isocyanate by ad igermyne [LGeÀGeL] (L = N(Ar*)(SiMe 3 ), Ar* = C 6 H 2 {C(H)Ph 2 } 2 Me-2,6,4) to give the bis(germylene)o xide compound [Ar*GeOGeAr*] has also been documented. [41] Gallium(I) complexes could be converted into galloxane speciesb yr eacting them with N 2 Oa nd O 2 .…”

“…The adduct [L 1 Ga‐(μ‐O) 2 ‐GaL 1 ] has been reported previously . Cleavage of the C=O double bond of an isocyanate by a digermyne [LGe−GeL] (L=N(Ar*)(SiMe 3 ), Ar*=C 6 H 2 {C(H)Ph 2 } 2 Me‐2,6,4) to give the bis(germylene) oxide compound [Ar*GeOGeAr*] has also been documented .…”

Molecular Main Group Metal Hydrides

“…Chelating diamido ligands have also been employed for the stabilization of gallium hydride systems. − Jones and coworkers have exploited oxidative reactions of E–H bonds (E = C, N, O) at the Ga­(I) center of the anionic five-membered heterocycle [(HCNDipp) 2 Ga] − to generate both neutral and anionic systems containing terminal Ga–H bonds. A related (albeit monoanionic) structural motif has been employed by Fedushkin and coworkers for the synthesis of gallium mono- and dihydride complexes . Reaction of dichlorogallane [HGaCl 2 ] 2 with the mono-sodium salt of the [dpp-BIAN] •‑ radical anion (dpp-BIAN = 1,2-bis­{(2,6-diisopropyl­phenyl)­imino}­acenaphthene) yields the paramagnetic Ga­(III) hydride chloride complex [(dpp-BIAN)­GaH­(Cl)] • ( 644 ) in which the unpaired spin density resides primarily on the unsaturated ligand backbone (Scheme ).…”

Main‐Group Metal Complexes in Selective Bond Formations Through Radical Pathways

“…A range of Group 13 BIAN complexes with the ligand in its radical monoanionic form have been reported (BIAN=1,2‐bis(arylimino)acenaphthene; for a Mg BIAN complex see Scheme ). The compounds undergo selective reactions such as M−H, M−C, M−O, and M−F bond formations (M=Al, Ga) . This occurs along with the activation of C−H (alkynes), Si−H (silanes), N−O (N 2 O), C−F (C 6 F 5 groups), and P−F (PF 6 − ) bonds, as well as C−C multiple bonds.…”