?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%2F8836%2F&rft.title=Evaluation+of+the+halogen+bond+and+the+salt+bridge+interaction+using+the+molecular+torsion+balance&rft.creator=Keyser%2C+Sandra+Kim&rft.description=A+molecular+torsion+balance+was+synthesized+to+study+the+halogen+bond+in+nonpolar+and+polar+solvents.+The+folding+energies+were+found+to+be+between+-0.2+and+-0.3+kcal%2Fmol+in+deuterochloroform.+The+strength+of+the+halogen+bond+decreased+in+the+following+order%3A+Cl+~+Br+%3E+I%2C+which+is+contrary+to+the+computationally+predicted+order%2C+I+%3E+Br+%3E+Cl.+This+reversed+trend+may+be+due+to+the+gauche+effect+and%2For+simultaneous+steric+effects+specific+to+our+model+system.+Three+different+functionalities%2C+an+alcohol%2C+a+carbamate%2C+and+an+amide%2C+were+used+as+the+halogen+bond+acceptors.+The+amide+gave+among+the+highest+folding+ratios%2C+indicative+of+the+strength+of+the+halogen+bond+with+bromide+or+chloride.+Solvent+studies+were+performed+on+the+brominated+torsion+balance+as+well+as+a+hydroxy+analog+to+compare+the+hydrogen+and+halogen+bonding+interactions.+Based+on+the+solvent+data%2C+it+takes+more+water+to+obstruct+a+halogen+bond+compared+to+a+hydrogen+bond.+The+folding+energies+were+also+compared+to+several+solvent+parameters.+A+molecular+torsion+balance+was+also+successfully+synthesized+to+study+the+solvent+exposed+salt+bridge+interaction+in+water+and+in+several+buffer+solutions.+We+found+that+the+folding+energies+varied+between+-0.3+to+-0.5+kcal%2Fmol+for+the+ammonium-carboxylate+and+guanidinium-carboxylate+interaction+when+exposed+to+solvent%3B+unequivocally%2C+salt+bridges+that+are+exposed+to+solvent+are+stabilizing.+Temperature+is+negligible+whereas+ionic+strength+has+a+weak+but+experimentally+significant+effect+on+the+strength+of+the+salt+bridge+interaction.+The+only+measurable+change+in+the+folding+ratios+came+from+adjusting+the+pD+of+the+buffer+solutions.&rft.date=2010-09-30&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%2F8836%2F1%2FKeyser_Sandra_ETD_corrected_082010.pdf&rft.identifier=++Keyser%2C+Sandra+Kim++(2010)+Evaluation+of+the+halogen+bond+and+the+salt+bridge+interaction+using+the+molecular+torsion+balance.++Doctoral+Dissertation%2C+University+of+Pittsburgh.++++(Unpublished)++