Synthesis, Structures, and Thermal Properties of Symmetric and Janus "Lantern Cage" Siloxanes.

Symmetric and asymmetric (Janus-type) new "lantern cage" siloxanes (PhSiO ) (Me SiO) (RSiO ) (R=Ph or iBu) were synthesized through reaction of all-cis-[PhSi(OSiMe Br)O] with all-cis-[RSi(OH)O] (R=Ph or iBu). These precursors were obtained by facile two or three-step reactions from commercially available compounds. The spectroscopic properties of the resulting products were fully characterized and they showed high thermal stability and sublimation without decomposition.