Janus cube: A new, economical way to synthesize ‘two-faced’ organosilicons

Professor Masafumi Unno and colleagues at Gunma University (Kiryu City, Japan; element.chem-bio.st.gunma-u.ac.jp) have developed a simple method for the synthesis of “Janus cubes,” which are nano-sized organosilicons with two different substituents (diagram). These nanoparticles — named after the two-faced Roman god — are useful raw materials with a unique structure used in the creation of high-performance silicon and silicone materials, but an economical process for making them has eluded researchers until now. The Gunma chemists synthesized and characterized a “perfect” Janus cube, octasilsesquioxane, which is an organosilane containing fluorine. It was made by a novel siloxane bond-forming reaction involving coupling a silanol salt and fluorosilane: the cross-coupling of sodium cyclosiloxanolate and cyclic fluorosiloxane “half-cubes.” The reaction is performed under mild conditions, does not generate any byproducts and is expected to be applicable for making organic-inorganic hybrid materials, the researchers say. The achievement is part of a project that is being led by Kazuhiko Satoh at the National Institute of Advanced Industrial Science and Technology (AIST; Tsukuba; www.aist.go.jp) with support from the…