Gyroscope Like Metal Complexes

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The Chemical Synthesis Program of the Chemistry Division of the National Science Foundation supports the research led by Professor John Gladysz of Texas A & M University. The project focuses on the design and synthesis of molecules that act as gyroscopes. These compounds have potential applications for sensors and guidance devices. Like classic mechanical gyroscopes - a device consisting of a wheel or disk mounted so that it can spin rapidly about an axis, the new molecules have a rigid axis composed of phosphorus-metal-phosphorus bonds and flexible linking groups connected to the polar phosphorus atoms that may rotate about the axis. This project aims to create molecules that both resemble mechanical gyroscopes and reproduce their functions. This research is important as it demonstrates complex design and synthesis protocols that may enable new molecular machines to be constructed. This project provides broad training for undergraduate, graduate student, and postdoctoral coworkers, as well as high school students and teachers. The team acquires expertise in synthesis, characterization techniques, oral presentation skills, report writing, laboratory safety, data management, and working in teams that are diverse with respect to gender, ethnicity, and nationality. Results are disseminated in the peer-reviewed scientific literature (including open access media), in lectures to undergraduate groups, at "open houses" for the lay public, and at diverse meetings and conferences.This project focuses on the synthesis, fundamental structural and dynamic properties, and reactivity of gyroscope-like metal-based molecular rotors. These molecular gyroscopes feature a metal fragment encased in a cage-like trans-dibridgehead diphosphine ligand in which the phosphorus atoms are spanned by three hydrocarbon chains. If the ligands are sufficiently small relative the linkages, the metal units rotate within the cage. Arrays of gyroscope-like units with parallel axes can be synthesized with spacings that allow the rotators to interact, enforcing correlated motion such as in gearboxes. The metal fragments also can be removed, providing new classes of macrocyclic dibridgehead diphosphines. These ligands are able to turn themselves "inside out", and be applied as container molecules that transport precious metals from one aqueous phase to another, leaving base metals behind.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.