Unexpected Formation of Ga₄C₂H₄ Heteroadamantane Cages by the Reaction of Carbon-Bridged Bis(dichlorogallium) Compounds with tert-Butyllithium

Abstract

Reactions of the carbon-bridged bis(dichlorogallium) compounds (Cl3a to 3c), via β-elimination and release of isobutene. 3a to 3c are dimeric in solution and the solid state and contain unprecedented Ga 4 C 2 H 4 heteroadamantane structures in which four metal atoms are bridged by four hydrogen and two carbon atoms. In contrast, n-propyllithium gave the monomeric tetra(n-propyl)digallium compound ( n Pr 2 Ga) 2 C(SiMe 3 )-CH 2 -Ph (2) under similar conditions, which has two coordinatively unsaturated gallium atoms and may be applicable as a chelating Lewis acid.

Origin and Location of Electrons and Protons during the Formation of Intermetalloid Clusters [Sm@Ga3−xH3−2xBi10+x]3− (x=0, 1)

“…Besides sharp signals of [2.2.2]crypt and DMF molecules, a broad signal is observed at a chemical shift of δ =4.03 ppm, which narrows with decreasing temperature (Figure S3). Since Sm 3+ is known not to affect the 1 H proton resonance, because of its weak paramagnetism and therefore low influence on signal shift and peak broadening,11a–c the signal broadening in the spectrum of 1 is ascribed to the coupling with 69 Ga and 71 Ga (both I = 3 / 2 )11d and the chemical exchange of the proton position—in agreement with the proposed structural properties and the temperature dependency of the NMR signal.…”

Poly‐Boron, ‐Silicon, and ‐Gallium Lewis Acids by Hydrometallation of 1,5‐ and 1,8‐Dialkynylanthracenes

“…Prominent examples include mercury,1 tin2 and silicon,3 for example, the trisilacyclohexane derivative reported by Brondani et al3a or the Si‐based crown ether analogue reported by Jung and Xia 3b. Remarkable progress in the field of poly‐Lewis acids based on aluminium4 and gallium [4e–4g,5] has been achieved by Uhl and co‐workers with hydroalumination4d–4f and hydrogallation reactions employing dialkylgallanes [4e,4f,5a–5c] and dichlorogallane as reagents,5d–5g respectively. The synthesis of dichlorogallane (HGaCl 2 ) 2 6 and its application in the hydrogallation of unsaturated substrates7 was first investigated by Schmidbaur and co‐workers.…”

Unusual reaction pathways of gallium(III) silylamide complexes

“…They assume that the large steric bulk of the organic substituents is the driving force for the alkene elimination in order to reduce steric congestion. Uhl et al performed a similar reaction starting from (Cl 2 Ga) 2 C(SiR 2 R′) CH 2 Ph (a: R = R′ = Me; b: R = Ph, R′ = Me; c: R = Me, R′ = t Bu) and t BuLi to give a tetranuclear cluster, where each gallium atom bears one tert-butyl group and one hydride (Chart 2E) (Uhl et al, 2011). Isobutene elimination was observed as well.…”

“…2 R′)CH 2 Ph} 2 (a: R = R′ = Me; b: R = Ph, R′ = Me; c: R = Me, R′ = t Bu; Bn=benzyl)(Uhl et al, 2011); (F) {(SiMe 3 ) 3 CGaH[μ-P(C 6 H 5 ) 2 ]} 2(Uhl and El-Hamdan, 2006); (G) [GaCp* 2 ‧carbene] + [Cp*] -transition state and GaCp* 2 H‧carbene(Gorden et al, 2002).Brought to you by | Universitaet Giessen Authenticated Download Date | 6/11/15 10:06 AM Scheme 2 Reaction of AlCl 3 and LiN(SiHMe 2 ) 2 to give homoleptic Al[N(SiHMe 2 ) 2 ] 3 (3) and side product 3a.…”