Isolation and Characterization of a Silicon-Organic Complex from Plants

Summary

Complex formation of silica, silicic acids and silicates with organic compounds has been investigated with emphasis on six-coordinated silicon. 1,2-Dihydroxyaryl compounds are powerful chelating agents for silicon, forming anionic complexes. Even quartz can he reacted directly to these compounds. Cationic chelate complexes are formed with 1,3-diketones, 2-hydroxypyridine-N-oxide and tropolones. A β-isopropyltropolone-silicon-complex (=β-thujaplicine-complex) ((thpl)₃Si)⁺ has been isolated from Thuja plicata. The natural complex has been compared with the synthetic compounds

$$ \begin{array}{l} {\rm{((thpl}}{{\rm{)}}_{\rm{3}}}{\rm{Si)Cl}}\,{\rm{ \times }}\,{\rm{2HCl,}}\,{\rm{((thpl}}{{\rm{)}}_{{\rm{3}}\,}}{\rm{Si)Cl}}\,{\rm{ \times }}\,{\rm{2}}{{\rm{H}}_{\rm{2}}}{\rm{O,}}\,{\rm{((thpl}}{{\rm{)}}_{\rm{3}}}\,{\rm{Si)P}}{{\rm{F}}_{\rm{6}}}, \\ {\rm{((thpl}}{{\rm{)}}_{\rm{3}}}{\rm{Si)}}\,{\rm{AuC}}{{\rm{l}}_{\rm{4}}}{\rm{,}}\,{\rm{and}}\,{{\rm{((thpl}}{{\rm{)}}_{\rm{3}}}{\rm{Si)}}_{\rm{2}}}{\rm{PtC}}{{\rm{l}}_{\rm{6}}}{\rm{.}} \\ \end{array} $$