?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F9572%2F&rft.title=Modeling+Organorhodium+Catalysis&rft.creator=Bayden%2C+Alexander+S&rft.description=The+first+project+considered+in+this+dissertation+was+the+improvement+of+an+existing+global+optimization+algorithm+that+uses+extended+dimensionality+to+find+global+minima+of+Lennard-Jones+clusters.+The+speed+of+this+algorithm+was+increased+by+three+orders+of+magnitude%2C+primarily+by+improving+the+algorithm+for+compressing+the+system+from+4D+to+3D+at+constant+energy.+The+second+project+was+modeling+the+adsorption+of+H2+molecules+on+the+Si(100)+surface+using+density+functional+theory+(DFT)+with+the+PW91+functional.+Consistent+with+the+experiments%2C+the+calculations+predicted+an+energetic+preference+for+clustering+of+occupied+sites+in+a+dimer+row.+However%2C+our+calculations+did+not+verify+the+unbuckling+induced+by+H2+adsorption+reported+by+Buehler+and+Boland.+The+third+project+was+modeling+molybdenum+and+rhodium-catalyzed+%5B2+%2B+2+%2B+1%5D+cycloisomerization+reaction+using+DFT+with+the+B3LYP+functional.+We+found+that+in+the+rhodium-catalyzed+%5B2+%2B+2+%2B+1%5D+cycloisomerization+reactions+of+allenes+the+oxidative+addition+step+determined+both+the+rate+and+the+product+of+the+reaction.+For+the+molybdenum-catalyzed+reaction+the+rate+was+controlled+not+by+oxidative+addition%2C+but+by+the+next+step%2C+the+attachment+of+a+carbon+monoxide+molecule+from+the+media+to+the+molybdenum+atom.+The+fourth+project+was+modeling+the+transfer+of+hydrogen+from+one+side+of+the+heterocyclic+ring+to+another+in+rhodium(I)+catalyzed+allenic+Pauson-Khand+type+reactions.+Our+calculations+showed+that+this+process+occurs+after+the+cyclization+step.+We+have+also+discovered+a+novel+mechanism+for+this+process+-+hydride+transfer%3B+however%2C+we+believe+that+in+most+cases+the+reaction+proceeds+by+beta-hydride+elimination.&rft.date=2006-03-16&rft.type=University+of+Pittsburgh+ETD&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F9572%2F1%2FAlexanderSBayden-Nov28-2005-v3.pdf&rft.identifier=++Bayden%2C+Alexander+S++(2006)+Modeling+Organorhodium+Catalysis.++Doctoral+Dissertation%2C+University+of+Pittsburgh.++++(Unpublished)++