Synthesis and Structures of Extended Cyclic Siloxanes
2014; Wiley; Volume: 25; Issue: 6 Linguagem: Inglês
10.1002/hc.21198
ISSN1098-1071
AutoresMasafumi Unno, Hisayuki Endo, Nobuhiro Takeda,
Tópico(s)Advanced ceramic materials synthesis
ResumoABSTRACT The facile synthesis of all‐ cis ‐tetrasiloxycyclotetrasiloxanes (extended cyclic siloxanes) [ i ‐BuSi(OSiHMe 2 )O] 4 1 , [PhSi(OSiHMe 2 )O] 4 2 , and [CH 2 = CHSi(OSiHMe 2 )O] 4 3 was accomplished via sodium or potassium silanolates from respective trialkoxysilanes. The treatment of 1 or 2 with m ‐chloroperoxybenzoic acid afforded respective extended cyclic silanols [ i ‐BuSi(OSiMe 2 OH)O] 4 4 and [PhSi(OSiMe 2 OH)O] 4 5 . The structures of 4 and 5 were unequivocally established by X‐ray crystallography. Among these new compounds, compound 3 possesses both vinyl and hydrosilyl groups in the molecule, thus this could serve as a potential monomer of well‐defined cage silsesquioxanes. Extended cyclic silanols 4 and 5 contain four silanol moieties in the same direction, and application of host molecules or building units of cage silsesquioxanes is expected.
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