One of the distinguishing features of metal-organic frameworks and other non-traditional porous materials, such as interlocked cage molecules, is their ability to respond flexibly to changes in their environment by changing their structures. There are a variety of mechanisms for this, including the relative displacement of two rigid networks and the repositioning of a linker with respect to an inorganic building unit. We have concentrated on rotations about single bonds in organic linkers as a route to change structures that has some similarities with the restructuring mechanisms adopted by biological molecules. This presentation will both review progress and cover recent results that include a new system that adopts multiple distinct crystal structures by this single bond rotation mechanism.(1)