Reactions of Distibines Sb₂R₄ and Dibismuthine Bi₂Et₄ with Trialkyltrieles MR₃

Abstract

Distibines Sb2R4 react with trimethylgallane and -indane (MMe3; M = Ga, In) with formation of heterocycles of the general type [Me2MSbR‘2]3 (R‘ = Me, M = Ga (2), In (3); R‘ = i-Pr, M = Ga (4)), whereas only decomposition reactions were observed for reactions with trialkylalanes. However, the mononuclear distibine−alane adduct [Al(t-Bu)3][Sb2(i-Pr)4] (1) with the distibine serving as monodentate ligand could be isolated and structurally characterized. In addition, reactions of the dibismuthine Bi2Et4 with M(t-Bu)3 (M = Al, Ga) were investigated, resulting in the formation of the simple Lewis acid−base adducts Et3Bi-M(t-Bu)3 (M = Al (5), Ga (6)). 1−6 were characterized by multinuclear NMR and mass spectroscopy and elemental analysis as well as single-crystal X-ray diffraction.

Reactions of Group 13 Organometallics tBu3M with Distibanes Sb2R4

“…[12] 2.830(1), 2.838(1) Å; [13] tBu 2.817(1) Å; [14] Ph 2.844(1) Å; [15] SiMe 3 2.867(1) Å; [15] SnMe 3 2.866(1) Å [16] }. There is no sign of any Sb-Sb bond weakening upon coordination to Lewis acidic tBu 3 M. Comparable findings have been previously observed for other distibane adducts [tBu 3 Al] x [Sb 2 R 4 ] [R = Me 2.811(1), [5] Et 2.838(1), [5] iPr 2.855(1) Å [7] ]. The most significant structural change of the distibane moiety due to the adduct formation is the increase of the degree of pyramidalization of the cenwww.eurjic.org tral Sb atoms.…”

“…The Al-Sb bond length observed for 1 [2. [17] Distibane adducts of trialkylgallanes and -indanes have been previously found to tend to undergo consecutive SbSb bond-cleavage reactions in solution with subsequent formation of heterocyclic stibanylgallanes and -indanes [R 2 MSbRЈ 2 ] x , whereas the corresponding Al-Sb heterocycles were not formed. [5,7] The same trends were observed for the distibane adducts 1-4. Alane adducts 1 and 2 remained unchanged in solutions of pentane or hexane and can be stirred for days without any sign of decomposition whereas tBu 3 Ga reacts with Sb 2 R 4 (R = iPr, iBu) with almost quantitative formation of the corresponding Ga-Sb heterocycles [tBu 2 GaSb(nPr) 2 ] 2 (5) and [tBu 2 GaSb(iBu) 2 ] 2 (6) within four days.…”

“…The reaction of Sb 2 (iPr) 4 with tBu 3 Al was previously shown to yield [tBu 3 Al][Sb 2 (iPr) 4 ]. [7] Reactions of Sb 2 R 4 (RЈ = nPr, iPr, iBu) with tBu 3 M (M = Al, Ga) yielded Lewis acid-base adducts [tBu 3 (2); M = Ga, R = nPr (3), iPr (4)], which were isolated as light-yellow, crystalline solids after crystallization from solutions in pentane at -40°C [Equation (1) 3 M as well as from typical fragmentation reactions. Single crystals of 1 suitable for an Xray structure determination were obtained from a solution in pentane at -30°C.…”

“…Only tetraisopropyldistibane was found to form the monoadduct [tBu 3 Al][Sb 2 (iPr) 4 ] when reacted with tBu 3 Al, most likely because of the increased repulsive interactions caused by the bulky iPr substituents. [7] The distibane alane adducts [R 3 Al] 2 [Sb 2 RЈ 4 ] were found to be stable in their pure form and in solution, [8] whereas the corresponding gallane and indane adducts [R 3 [9] and transition metal complexes. [10] [tBu 2 GaSb(iBu) 2 ] 2 (6).…”

Coordination chemistry of the main group elements with phosphine, arsine and stibine ligands

“…A range of examples with SbR 3 and BiR 3 is also known (Fig. 32), although these are particularly sensitive compounds, and contain much weaker Ga-E bonds than the lighter Group 15 analogues [149,154,[192][193][194][195]200]. Phosphine and arsine adducts of R 2 GaCl (R = Me, Me 3 CCH 2 , Ph) have been prepared [197,198,202].…”