Nanomaterials with novel size-dependent properties and potential applications for catalysis, gas storage, and controlled release formulations are increasingly emerging from rational design based on the understanding of relationships between structure at the molecular level and catalyst performance [1]. Furthermore, characterization of the nanomaterials under working conditions provides the best opportunity to obtain fundamental understanding of such relationships. Previous work has shown that Co(salen) nanoparticles unsupported [2] and supported on ã-Al₂O₃, using the compressed antisolvents (PCA) technology [3], have unique gas (NO, O₂, and CO) binding properties. In this work, we will report the in situ EXAFS, XANES, and Raman spectroscopy characterization of Co(salen) nanoparticles unsupported and supported on ã-Al₂O₃ during the binding of O₂ and NO. The results provide information regarding the changes in oxidation state of the Co, the coordination of the Co centers, and the ligands on the nanoparticle during O₂ or NO adsorption and desorption.

References: [1]. Guzman, J.; and Gates, B. C.; Dalton Trans. 2003, 3303–3318. [2]. Johnson, C. A.; Sharma, S.; Subramaniam, B.; and Borovik, A. S.; J. Am. Chem. Soc. 2005, 127, 9698–9699. [3]. Johnson, C. A.; Nguyen, J.; Subramaniam, B.; and Borovik, A. S.; 2007, to be submitted.