Novel 10- and 20-Membered Tin- and Silicon-Containing Rings:  Synthesis, Complexation Behavior, and Conversion into a Lewis Acidic Polymer^,

Abstract

Reaction of the dimethylsilylmethyl-substituted tetraorganotin derivative CH 2 [CH 2 Sn-(Ph 2 )CH 2 Si(H)Me 2 ] 2 (1) and CH 2 [CH 2 Sn(Ph 2 )CH 2 Si(i-PrO)Me 2 ] 2 (3), respectively, with mercuric chloride afforded the novel silicon-and tin-containing 10-and 20-membered rings cyclo-CH 2 [CH 2 Sn(Cl 2 )CH 2 Si(Me 2 )] 2 O (4) and cyclo-CH 2 [CH 2 Sn(Cl 2 )CH 2 Si(Me 2 )OSi(Me 2 )CH 2 -Sn(Cl 2 )CH 2 ] 2 CH 2 (5). Both compounds 4 and 5 can be converted into the soluble Lewis acidic polymer poly-[Si(Me 2 )CH 2 Sn(Cl 2 )(CH 2 ) 3 Sn(Cl 2 )CH 2 Si(Me 2 )O] (8). 119 Sn NMR studies indicate that 4 acts as a bidentate Lewis acid toward chloride ions, exclusively forming the 1:1 complex [cyclo-CH 2 [CH 2 Sn(Cl 2 )CH 2 Si(Me 2 )] 2 O‚Cl] -[(Ph 3 P) 2 N] + (7). The molecular structures as determined by single-crystal X-ray diffraction analysis of 4 and 7 are reported.

Organotin‐Substituted Crown Ethers for Ditopic Complexation of Anions and Cations

“…However, an essential shortcoming of the latter compounds is the kinetic lability of the tin-carboxylate bond, which makes the corresponding zwitterionic complexes unstable in solution. [18b] In continuation of our own studies on organotin halides as Lewis acids for selective complexation of anions [21][22][23] we report here the synthesis and structures of kinetically more stable carbon-bonded organotin-functionalized crown ethers and demonstrate that such compounds are able to complex and transport sodium rhodanide in nonpolar organic solvents.…”

“…[26,27] The equatorial positions are occupied by C(1), C(11), C(21) and the axial positions by Cl(1) and the water oxygen atom. The tin atom is displaced by 0.22 Å from the plane defined by C(1), C(11), C (21) . These results are supported by NOE decoupling experiments at different temperatures.…”

The Charge‐Reverse Analogy as an Inspiration for the Preparation of Polydentate Lewis Acidic Boranes

“…Whereas several tin4 and mercury1a,b, 5 analogues of crown ethers exist, most of the boron systems investigated to date feature open‐framework structures. Their design is inspired from bidentate Lewis bases that incorporate rigid aromatic backbones.…”

Die Ladungsumpolungs‐Analogie als Inspiration für die Synthese mehrzähniger Lewis‐saurer Borane

“…Während es mehrere Zinn‐4 und Quecksilber‐Analoga1a,b, 5 der Kronenether gibt, haben die meisten bis heute erforschten Borsysteme offene Strukturen. Ihr Design wurde von zweizähnigen Lewis‐Basen mit einem starren aromatischen Gerüst inspiriert.…”