UC Santa Barbara

For the first part of this work, we explored the potential of repetitively cycling the orthosubstituted carborane, 1,2-(Ph2PO)2-1,2-C2B10H10 (POCb), by galvanostatic bulk electrolysis (GBE) to capture and release the uranyl cation, UO2 2+ . The metal capturing process worked successfully for the first cycle of GBE and captured UO2 2+ successfully in the form of [UO2( POCb)2] . However, the second cycle of the GBE using the same POCb, does not show a significant amount of reduced POCb. The results show different side-products form after the second reduction step indicating that the second charge cycle to generate nidoPOCb, the reduced form of POCb was unsuccessful. By treating with different methods of extraction during the cycle of GBE, we were able to gain some understanding about what is hindering the second reduction. From series of experiments, we determined that a water adduct forms with closoPOCb and this hinders the ability of closoPOCb to be reduced properly, and therefore we could not capture much uranyl in the second cycle. These results are presented herein. The second part of the thesis investigates the capture of different lanthanide metals using nidoPOCb2- . Surprisingly, each lanthanide with nidoPOCb shows different coordination even though we added the same equivalents, 2.1:1. X-ray diffraction studies confirmed the different coordination environments. While the nature of this coordination remains under investigation, v we suspect that the high reduction potential of the lanthanide metal is likely at play. Further experiments were conducted to back up the idea.