Diaryltin Dihydrides and Aryltin Trihydrides with Intriguing Stability

Abstract

In the last few decades, organotin hydrides have proven their potential as building blocks for a great variety of organometallic compounds. In this context, organotin hydrides with sterically shielding aryl substituents have attracted special interest, as these ligands can kinetically stabilize metastable products. The selective synthesis of aryltin halide compounds Ar*2SnCl2 and Ar*SnI3 featuring the highly sterically encumbered aryl ligand Ar* (iPrAr* = 2,6-(Ph2CH)2-4-iPrC6H2; MeAr* = 2,6-(Ph2CH)2-4-MeC6H2) is presented. These aryltin halides were converted into corresponding aryltin hydrides Ar*2SnH2 and Ar*SnH3, which exhibit a surprisingly high thermal stability and oxygen tolerance.

A Distibene with Extremely Long Sb=Sb Distance and Related Heavier Dipnictenes from Salt‐Free Metathesis Reactions

“…[4] Anilines of the type Ar*NH 2 (Ar*=C 6 H 2 -2,6-(CHPh 2 ) 2 -4-iPr) have been applied in the stabilization of low-valent main group compounds in the past. [31][32][33][34][35][36][37] The preparation and subsequent application as ligand for aryltin hydrides, Ar* 2 SnH 2 and Ar*SnH 3 , as well as Ar*SbX 2 have been reported by our group, [26] and Schulz and Villinger, [27] respectively. Yet, the potential of this ligand to stabilize low-valent heavier main group compounds and the resulting geometry around the heavier atoms remains unexplored so far.…”

“…[5] Additionally, experiments with the highly crowded ligand Ar* (Ar*=C 6 H 2 -2,6-(Ph 2 CH) 2 -4-iPr) were conducted in this respect. [26,27] Element chloride precursors, Ar Dipp ECl 2 (E=Sb, Bi), were prepared following known procedures in salt-metathesis reactions of Ar Dipp Li with the corresponding element chlorides, ECl 3 (E=Sb, Bi). Conversion of the starting material was monitored via NMR spectroscopy and subsequent standard workup procedures and recrystallization gave both Ar Dipp SbCl 2 (1) and Ar Dipp BiCl 2 (3) as crystalline products in fair yields around 80 %.…”

“…[27] For the preparation of the corresponding arylantimony dihydride, Ar*SbH 2 , the widely applied hydride transfer reaction with LiAlH 4 , similar than for Ar* substituted tin hydrides, was chosen. [26] At 0 °C, 5 was added in portions to a suspension of LiAlH 4 in Et 2 O/toluene (due to low solubility of 5 in Et 2 O alone) and subsequently stirred for ca. 2 h. Aqueous workup with dilute degassed sulfuric acid was carried out, while maintaining anaerobic conditions and residual aluminum salts were removed by washing the organic layer with degassed saturated potassium tartrate solutions.…”

“…Resonances for SbH are observed at δ = 5.20 ppm, which is again somewhat upfield shifted compared to its diorganotin dihydride derivative, Ar* 2 SnH 2 (δ = 5.55 ppm). [26] Conversion of Ar* 2 SbH with Bi(NEt 2 ) 3 in a 3 : 1 ratio led to the formation of the distibene Ar*Sb=SbAr* (11). Dropwise addition of DME solutions of the amide species to 6 in DME/toluene resulted in an immediate color change to dark brown.…”

Oligoorganogermanes: Interplay between Aryl and Trimethylsilyl Substituents

“…Research into organic derivatives of main group elements is a topical issue of organometallic chemistry [ 1 , 2 , 3 , 4 ]. Many efforts have been made to develop improved synthetic methods, determine new properties, find relationships between structures and properties, and produce novel materials.…”