This award from the Chemistry Research Instrumentation and Facilities Program will assist the Department of Chemistry at University of Wyoming to acquire an upgrade of a Siemens P3 X- ray diffractometer to the P4 model. This equipment will enhance research in a number of areas including the following: (1)structural investigations of fluoroalkylphosphine complexes, (2) structural and reactivity correlations in iron nitrosyls, (3) Diels-Alder reactions within vesicles and the aggregate morphology of novel surfactants, and (4) structural studies of nitrogen oxyanions and luminescent molecular rectangles. The X-ray diffractometer is used to make accurate and precise measurements of the full three dimensional structure of a molecule. The information obtained gives the precise values of all the bond distances and bond angles of a given molecule and it gives accurate information about the spatial arrangement of the molecule relative to the neighboring molecules.