Catalytic dehydrogenative coupling of diorganotindihydrides by lanthanide diamide complexes

Abstract

Despite the fact that sterically demanding 1,2-dihydrodistannanes are versatile synthons, their synthesis is typically a tedious, low-yield procedure, which limits synthetic applications. Looking for generally applicable and high-yield routes, we examined the dehydrogenative coupling of sterically crowded diorganotindihydrides. Herein, we report the application of lanthanide diamide-based catalysts (CH 2 ) 3 -1,3-[N(Dipp)] 2 LnBr (Ln=La,Ce,Nd,Dy) to generate polystannanes and distannanes, depending on the size of the aromatic substituents. Reaction of t Bu 2 SnH 2 resulted in the quantitative formation of 1,1,2,2-tetra-tertbutyldistannane while conversion of sterically encumbered Mes 2 SnH 2 yielded 1,1,2,2-tetramesityldistannane.

Controlled Growth of Dichlorogermanium Oligomers from Lewis Basic Hosts

“…[1] Amongst the inorganic Group 14 tetrel elements, it has been shown that catenation leads to species of the general form (R 2 E) n (E = Si, Ge, Sn, and Pb); these materials display novel optoelectronic properties as a result of increasing s-s* conjugation, both as the length of the chains is extended and as the core element becomes heavier. [4,5] Drawn by this challenge and the uncertainty associated with the structures of the metastable halides (SiCl 2 ) n and (GeCl 2 ) n in the solid state, [6] we focused our efforts towards developing an efficient bottom-up synthesis of related oligomers and polymers (ECl 2 ) x (x ! [3] In general, polytetrelanes (R 2 E) n are synthesized under harsh reducing conditions, such as Wurtz coupling, which leads to uncontrolled polymer growth.…”

“…[3] In general, polytetrelanes (R 2 E) n are synthesized under harsh reducing conditions, such as Wurtz coupling, which leads to uncontrolled polymer growth. [4,5] Drawn by this challenge and the uncertainty associated with the structures of the metastable halides (SiCl 2 ) n and (GeCl 2 ) n in the solid state, [6] we focused our efforts towards developing an efficient bottom-up synthesis of related oligomers and polymers (ECl 2 ) x (x ! 2) in the presence of Lewis basic (LB) hosts.…”

“…This product was recrystal-lized from CH 2 Cl 2 to give the linear tetrachlorodigermene adduct IPr·GeCl 2 GeCl 2 (1) as pale yellow crystals in a 75 % yield ( Figure 1). [12,13] The C IPr -Ge bond length in IPr·GeCl 2 GeCl 2 (1) is 2.032 (5) , which is shorter than the related distance in IPr·GeCl 2 (2.112(2) ), [10a] whereas the two GeCl 2 units in 1 are linked in nearly eclipsed arrangements when viewed down the Ge-Ge bond vector (for example, Cl1-Ge1-Ge2-Cl3 torsion angle = 22.85(7)8). The Ge-Ge bond distance in 1 is 2.6304 (9) and longer than most typical Ge-Ge single bonds (ca.…”

Stabilizing, non-covalent interactions in the solid state structure of novel aryltin hydrides and halogenides

“…47 Furthermore in the last decade, organotin dihydrides (R 2 SnH 2 ) have been explored as precursors in the formation of polymeric materials exhibiting a linear backbone of covalently bonded tin atoms. 28,[48][49] However, the solid state structures of organotin hydrides have not been well studied. While alkyl tin hydrides are liquid, the only solid state examples of aryltin hydrides known to date have been isolated by our working group and include mesityl 2 SnH 2 , 28 phenyl 3 SnH, 44 and 2,6-xylyl 3 SnH (8) ( Table 3).…”

“…[20][21][22][23][24][25][26][27] However, solid state examples of trichlorides are limited, and the only aryltin hydride species to have been characterized crystallographically is Mes 2 SnH 2 (Mes = 2,4,6-trimethylphenyl). 28 Very recently, we reported the synthesis, detailed characterization, and DFT studies of novel aryltin chloride and hydride species. 2 Their potential use as starting materials for polyarylstannanes provided the motivation to establish the generation of aryltin trihydrides displaying a hitherto more or less neglected compound class of organotins.…”