title: Relative substituent position on the strength of pi-pi stacking interactions.
abstract: It was observed that the relative position of the arene substituents have a profound influence on the strength of pi-pi stacking in the 9-benzyl substituted triptycene system. A new series of model compounds (3a-i) capable of revealing quantitatively pi-pi stacking interactions was studied. This series of compounds (3a-i) has an ortho substituted methyl group in one of the two interacting arenes and the syn/anti ratios were determined and compared to a series previously studied compounds (4a-i) that have a para methyl group on the corresponding arene. A greater than 50% increase in the strength of pi-pi stacking interactions was observed with the methyl group in the ortho position comparing to that in the para position. No difference in pi-pi stacking interactions was observed when the other aromatic ring was a pentafluorobenzoate group.
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056.
authors.forename: Benjamin W
authors.initials: BW
authors.lastname: Gung
authors.forename: Bright U
authors.initials: BU
authors.lastname: Emenike
authors.forename: Celeste N
authors.initials: CN
authors.lastname: Alverez
authors.forename: John
authors.initials: J
authors.lastname: Rakovan
authors.forename: Kristin
authors.initials: K
authors.lastname: Kirschbaum
authors.forename: Nirbhay
authors.initials: N
authors.lastname: Jain