%0 Journal Article
%A Wolk, Arron
B.
%A Garand, Etienne
%A Jones, Ian M.
%A Hamilton, Andrew D.
%A Johnson, Mark A.
%D 2013
%T Quantifying Intrinsic
Ion-Driven Conformational Changes
in Diphenylacetylene Supramolecular Switches with Cryogenic Ion Vibrational
Spectroscopy
%U https://acs.figshare.com/articles/journal_contribution/Quantifying_Intrinsic_Ion_Driven_Conformational_Changes_in_Diphenylacetylene_Supramolecular_Switches_with_Cryogenic_Ion_Vibrational_Spectroscopy/2392945
%R 10.1021/jp3111925.s001
%2 https://acs.figshare.com/ndownloader/files/4032637
%K Cryogenic Ion Vibrational SpectroscopyWe report
%K chloride concentrations
%K intramolecular
%K transition state
%K urea NH donors
%K 10 K ion trap
%K ion breaks
%K D 2 adducts
%K Na
%K TMA
%K Diphenylacetylene Supramolecular Switches
%K DPA
%K ion accommodation profile
%X We report how two flexible diphenylacetylene (DPA) derivatives
distort to accommodate both cationic and anionic partners in the binary
X±·DPA series with X = TMA+ (tetramethylammonium),
Na+, Cl–, Br–, and
I–. This is accomplished through theoretical analysis
of X±·DPA·2D2 vibrational spectra,
acquired by predissociation of the weakly bound D2 adducts
formed in a 10 K ion trap. DPA binds the weakly coordinating TMA+ ion with an arrangement similar to that of the neutral compound,
whereas the smaller Na+ ion breaks all intramolecular H-bonds
yielding a structure akin to the transition state for interconversion
of the two conformations in neutral DPA. Halides coordinate to the
urea NH donors in a bidentate H-bonded configuration analogous to
the single intramolecular H-bonded motif identified at high chloride
concentrations in solution. Three positions of the “switch”
are thus identified in the intrinsic ion accommodation profile that
differ by the number of intramolecular H-bonds (0, 1, or 2) at play.
%I ACS Publications