title: A new class of intramolecularly hydrogen-bonded dendrons based on a 2-methoxyisophthalamide repeat unit.
abstract: The synthesis and conformational properties of folded dendrons based on a 2-methoxyisophthalamide (2-OMe-IPA) repeat unit are described. The hydrodynamic properties of dendrons preorganized via the syn-syn conformational preference of 2-methoxyisophthalamide are compared with 2,6-pyridinedicarboxamide (2,6-pydic) analogues. The effect of subtle differences in the nature of the conformational equilibria that exist within the 2-OMe-IPA and 2,6-pydic repeat units on the global structural properties of the corresponding dendrons was explored computationally, by (1)H-DOSY NMR spectroscopy and time-resolved fluorescence anisotropy (TRFA) measurements. Whereas the syn-syn preference of the 2-OMe-IPA branched repeat unit is stabilized entirely by intramolecular hydrogen-bonding interactions, this preference in the 2,6-pydic system is a consequence of both intramolecular hydrogen-bonding and dipole minimization effects. However, nonspecific solvophobic compression is more important in determining hydrodynamic properties than solvent-dependent shifts in the conformational equilibria of the repeat unit for both dendron series.
authors.affiliation: Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gabriel
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Dematteo
authors.forename: Noel M
authors.initials: NM
authors.lastname: Paul
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Takaya
authors.forename: Terry L
authors.initials: TL
authors.lastname: Gustafson
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Hadad
authors.forename: Jon R
authors.initials: JR
authors.lastname: Parquette
mesh_terms: D000577:Amides / Q000737:chemistry*; D018360:Crystallography, X-Ray; D050091:Dendrimers / Q000737:chemistry*; D005454:Fluorescence Polarization; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D010795:Phthalic Acids / Q000737:chemistry*
chemical_list: C516982:2-methoxyisophthalamide; D000577:Amides; D050091:Dendrimers; D010795:Phthalic Acids