Extending Distannoxane Double Ladders Using Rigid Spacers: A Double Ladder with Eight Chiral Tin Atomsand a Twist!
journal contribution
posted on 2002-01-24, 00:00 authored by Dainis Dakternieks, Andrew Duthie, Bernhard Zobel, Klaus Jurkschat, Markus Schürmann, Edward R. T. TiekinkThe new bulky silicon-containing ditin precursor <i>p</i>-(RCl<sub>2</sub>SnCH<sub>2</sub>SiMe<sub>2</sub>)<sub>2</sub>C<sub>6</sub>H<sub>4</sub> (R = CH<sub>2</sub>SiMe<sub>3</sub> (<b>4</b>)) has been synthesized and further reacted to form a unique double ladder {[<i>p</i>-(R(Cl)SnCH<sub>2</sub>SiMe<sub>2</sub>)<sub>2</sub>C<sub>6</sub>H<sub>4</sub>]O}<sub>4</sub> (<b>6</b>). The two layers within <b>6</b> are twisted with respect to one
another, resulting in a helical motif and a total absence of molecular symmetry so that there
are eight chiral tin atoms within the system. The structure is compared to the double ladder
{[<i>m</i>-(R(Cl)SnCH<sub>2</sub>CH<sub>2</sub>)<sub>2</sub>C<sub>6</sub>H<sub>4</sub>]O}<sub>4</sub> (<b>11</b>), which was prepared from the less sterically demanding
ditin precursor <i>m</i>-(RCl<sub>2</sub>SnCH<sub>2</sub>CH<sub>2</sub>)<sub>2</sub>C<sub>6</sub>H<sub>4</sub> (<b>10</b>). The two layers within <b>11</b> are parallel, and
the molecule contains only two kinds of tin atom.
