This award supports international collaboration between Dr. Bruce Averill, Dr. Patricia Eldredge of the University of Virginia, and Professor Xu Jiqing of Jilin University on iron and molybdeum compounds related to the FeMo cofactor of nitrogenase. Under this award, the principal investigators from China and the US will work together on developing synthetic analogs of FeMo-co, the structure of which remains enigmatic. This collaboration will allow Professor Xu to combine his theoretical and mechanistic approach with Professor Averill's expertise in synthesis and characterization. The U.S.-China Program supports collaborative research of mutual benefit to the US and China.