%0 Online Multimedia %A J. T. Houk, Ronald %A Jacobs, Benjamin W. %A Gabaly, Farid El %A Chang, Noel N. %A Talin, A. Alec %A Graham, Dennis D. %A House, Stephen D. %A Robertson, Ian M. %A Allendorf, Mark D. %D 2009 %T Silver Cluster Formation, Dynamics, and Chemistry in Metal−Organic Frameworks %U https://acs.figshare.com/articles/media/Silver_Cluster_Formation_Dynamics_and_Chemistry_in_Metal_Organic_Frameworks/2821876 %R 10.1021/nl901397k.s002 %2 https://ndownloader.figshare.com/files/4519540 %K uniform arrays %K Ag 3 clusters %K silver nanocluster formation %K uniform pore sizes %K particle sizes %K metal nanoparticles %K representative MOF templates %K chemical stabilization %K Silver Cluster Formation %K MOF pores %X Synthetic methods used to produce metal nanoparticles typically lead to a distribution of particle sizes. In addition, creation of the smallest clusters, with sizes of a few to tens of atoms, remains very challenging. Nanoporous metal−organic frameworks (MOFs) are a promising solution to these problems, since their long-range crystalline order creates completely uniform pore sizes with the potential for both steric and chemical stabilization. We report a systematic investigation of silver nanocluster formation within MOFs using three representative MOF templates. The as-synthesized clusters are spectroscopically consistent with dimensions ≤1 nm, with a significant fraction existing as Ag3 clusters, as shown by electron paramagnetic resonance. Importantly, we show conclusively that very rapid TEM-induced MOF degradation leads to agglomeration and stable, easily imaged particles, explaining prior reports of particles larger than MOF pores. These results solve an important riddle concerning MOF-based templates and suggest that heterostructures composed of highly uniform arrays of nanoparticles within MOFs are feasible. %I ACS Publications