Solution 1H NMR confirmation of folding in short o-phenylene ethynylene oligomers.
Oligomers based on an o-phenylene ethynylene (oPE) backbone with polar substituents have been synthesized using Sonogashira methods. Folding of these extremely short oligomers was confirmed via 1D and 2D (NOESY) NMR methods. Utilizing electron-rich and electron-poor phenylene building blocks, variations of these oPE oligomers have been synthesized to determine the folded stability of pi-rich vs pi-poor vs pi-rich-pi-poor systems. Slight variations in temperature offer a route, aside from solvent denaturation, to probe the stability of the folded structure. This is the first report of an NMR solution characterization of folding for a PE backbone without hydrogen bonds.
Jones
Ticora V
TV
Polymer Science & Engineering, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Slutsky
Morris M
MM
Laos
Roberto
R
de Greef
Tom F A
TF
Tew
Gregory N
GN
D000480:Alkynes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation
D000480:Alkynes; C508010:o-phenylene ethynylene