The addition of 30% water (by volume) to acetone creates a remarkably effective polar phase solvent system for a dicationic dirhodium tetraphosphine hydroformylation catalyst. The initial turnover frequency (TOF) increases by 265% (to 73 min-1) for the hydroformylation of 1-hexene relative to the initial TOF in pure acetone (20 min-1). The aldehyde linear to branched (L:B) ratio increases to 33:1, and alkene isomerization and hydrogenation side reactions are essentially eliminated. Comparisons with monometallic rhodium catalysts based on PPh3, Bisbi, Naphos, and Xantphos ligands demonstrate that this polar-phase bimetallic catalyst is one of the fastest and most selective hydroformylation systems known under these mild conditions (90 degrees C, 6.2 bar H2/CO). The monometallic catalysts also show rate enhancements (although considerably smaller) in water-acetone, but Rh-Xantphos does show a large increase of 115%, with considerably reduced alkene isomerization side reactions. The dramatic effect of water on the dirhodium catalyst system is believed to be due to simple inhibition of the fragmentation of the catalytically active species into inactive mono- and bimetallic complexes.
Our work is to focus on making nanoparticles that will be used as a non-invasive method to monitor intracellular trafficking and the transfection of genes. The nanoparticles characterize gradients in oxygen tension and gene expression that occur in the biofilms. The nanoparticles are made by a few different procedures such as the Ormosil and Solgel pebble formation. The Ormosil formation makes silica particles which are used for gene delivery. This gene delivery can deliver antibiotics or any of the other medicines that could help to kill these biofilms, once something is found that can kill them these will be really useful. These nanoparticles also determine where and how much oxygen there is in the biolfilms. This can show you how bacteria are respiring and functioning and allows you to optimize conditions so you can, for example, prevent corrosion, enhance bioremediation, or enhance chemical production.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.