ABSTRACT

This Major Research Instrumentation (MRI) award supports the acquisition of a dual-source single-crystal x-ray diffractometer at Howard University, a Historically Black University (HBCU). This capability invigorates fundamental materials and catalysis research at Howard University, offering application opportunities in extending the benefits of single-crystal x-ray diffraction (SC-XRD) analysis to non-crystalline systems such as liquids and amorphous solids, decomposition of chemical warfare agents, analyte detection, energy storage, fossil energy conversion, molecular switches, and memory storage. SC-XRD is one of the most powerful techniques available to determine molecular structure. By shining a focused x-ray beam on a crystal, one can determine how atoms are connected in a molecule, how these atoms are spatially oriented, and how molecules are packed together in a crystal. Knowledge of atomic and molecular arrangement allows for a better understanding of how molecules function. This can ultimately lead to designing new materials, to revealing how living organisms operate, and to developing new therapeutics to alleviate human suffering. The strength of the generated x-ray beams permits rapid analysis of challenging samples. This instrument creates and fortifies existing collaborations and enhances research capability in the Mid-Atlantic region. The diffractometer also strengthens chemical education at Howard University and provides trainees a foundation to use advanced facilities at US national laboratories. These activities inspire underrepresented minorities to pursue chemistry and crystallography leading to further diversification of the national academic, governmental, and industrial workforce.

The acquired high-brilliance single-crystal x-ray diffractometer features dual microfocus Mo and Cu sources with multilayer optics, a pixel array detector that operates in a shutterless data acquisition mode, and a temperature control system for data collection within a range of 80?400 K. The dual-source configuration allows for the rapid collection of high-quality diffraction data to perform detailed analyses of microcrystalline and powder samples. The high-flux monochromatic x-rays permits the analysis of weakly-diffracting microcrystals. The projects that benefit from the new instrument involves the study of: (1) novel metal-organic frameworks (MOFs) as preformed crystalline matrices for use in molecular structure elucidation / mechanistic investigations involving non-crystalline compounds through the ?crystalline sponge method?, (2) carboranyl ligand design for catalysis in applications such as the decomposition of chemical warfare agents (CWA), (3) anisotropic nanoparticle composite synthesis for use in analyte detection through surface-enhanced Raman spectroscopy, (4) block copolymer strength for applications in dielectric energy storage, (5) ligand synthesis for iron(II) oxide core-shell microparticle generation through atmospheric pressure metal-organic chemical vapor deposition (AP-MOCVD) for application in fossil energy conversion processes, (6) investigation of spin crossover complexes for application in switches and memory storage, and (7) design of catalytic sequential processes to derivatize heterocyclic scaffolds for application in creating new spin crossover materials and drug-like molecules.

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.

Please report errors in award information by writing to: awardsearch@nsf.gov.