This award from the Chemistry Research Instrumentation Program will help the Department of Chemistry at the Univrsity of California at Los Angeles acquire an entire new integrated single crystal x-ray diffractometer and structure analysis system, with rotating anode generator. Among the areas of chemical research that will be enhanced by the acquisition are the following: 1. Host Molecules That Complex and Catalyze 2. Borane Cluster Chemistry 3. Porphyrin Sponges: Programmable Lattice Clathrates %%% Single crystal x-ray crystallography is the most powerful analytical method for structure determination of solids. In synthetic inorganic, organic, bioinorganic and organometallic chemistry, single crystal x-ray diffraction is an invaluable tool to characterize molecular structure. The information gained from the knowledge of the intermolecular composition and structure helps to develop new reactions of potentially general interest in catalysis or organic synthesis.