Self-limiting distortion by antirotating hinges is the principle of flexible but noncollapsible frameworks

摘要: Abstract Microporous frameworks formed by T O 4 coordination tetrahedra (with = Si or Al) in zeolites are systems composed of rigid parts, the tetrahedra, and joint oxygen atoms serving as flexible hinges between tetrahedra. It is known that these can be inflexible (or even rigid). Some most open tetrahedral display a pronounced resistance to collapse, when undergoing radical changes chemistry their embedded guests (ions molecules). A study empirically observed angular distortions zeolite (LTA) computer simulation show this property due self-regulating mechanism which allows dimensions framework only within limits set chemically possible values O angles bridging depends solely on topological, symmetrical, geometrical properties three-dimensional nets underlying frameworks. In collapsible corotate, compression tension at all exerted simultaneously same sense. noncollapsible antirotate, one hinge necessitates another vice versa.