Reactivity of Distibanes toward Trialkylalanes and -gallanes:  Syntheses and X-ray Structures of Bisadducts and Heterocycles

Abstract

Reactions between distibanes of the type Sb 2 R 4 and trialkylalanes and -gallanes R′ 3 M in 1:2 stoichiometry yield eight bisadducts of the type [Sb 2 R 4 ][MR′ 3 ] 2 (R ) Me, R′ ) t-Bu, M ) Al 1, Ga 2; R ) Et, M ) Al, R′ ) Me 3, Et 4, t-Bu 5; M ) Ga, R′ ) Me 6, Et 7, t-Bu 8), which were characterized by multinuclear NMR studies and elemental analysis. In addition, 1, 2, 5, and 8 are the first structurally characterized neutral main group Lewis acid-distibane bisadducts. 1-8 are unstable in solution toward the formation of heterocycles of the type [R 2 SbMR′ 2 ] x . [Me 2 SbGa(t-Bu) 2 ] 3 (9) and [Et 2 SbGa(t-Bu) 2 ] 2 (10) have been isolated and their solid state structures determined by 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.…”

“…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. [18] In contrast, the reaction of tBu 3 Ga with Sb 2 (iPr) 4 [5] whereas the formation of 5 and 6 requires longer reaction times. Compounds 5 and 6 were obtained as colorless crystalline solids in almost quantitative yields, which were recrystallized from solutions in hexane.…”

“…We started to investigate reactions of distibanes RЈ 2 SbSbRЈ 2 and dibismuthines RЈ 2 Bi-BiRЈ 2 with group 13 organometallics MR 3 (M = Al, Ga, In) because of our general interest in group 13/15 chemistry. These reactions typically yielded bisadducts of the type [R 3 M] 2 [E 2 RЈ 4 ] (M = Al, Ga; E = Sb, [5] Bi [6] ), with the dipenteles serving as bidentate ligands. 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.…”

Characterization of GaSb thin films from tailor-made single-source precursors

“…The used precursor (1) was synthesized using standard Schlenck-techniques and a glovebox with N 2 atmosphere for storage, following methods described elsewhere [4]. The compound was transferred into an ultra-high vacuum (UHV) chamber by using a closed glass vessel.…”