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561.
562.
Shannon Sestile David Richardson Ryan Toomey Laurence G. Cool James K. Harper 《Magnetic resonance in chemistry : MRC》2021,59(1):23-33
The connectivity, conformation, tautomeric form, and dynamics of a new depsidone (perisalazinic acid) were characterized using one‐bond 13C? 13C NMR scalar couplings (1JCC) obtained from the INADEQUATE experiment. Characterization of perisalazinic acid using more conventional NMR techniques is problematic due to the extremely limited number of C? H protons present. In the present study, 81 candidate structures were considered and a best fit structure was selected by comparing computed 1JCC values for each candidate to 15 experimental values. Of the six flexible moieties in perisalazinic acid, three are adequately represented by a single orientation stabilized by intramolecular hydrogen bonding. The three remaining groups are present as mixtures of conformers with two sites consisting of a pair of conformations and another disordered over six orientations. This study demonstrates the feasibility of complete three‐dimensional structural characterization of an unknown using only theoretical and experimental 1JCC values. 相似文献
563.
Rainer Fiesel Carrie E. Halkyard Mary E. Rampey Lioba Kloppenburg Shannon L. Studer‐Martinez Ullrich Scherf Uwe H. F. Bunz 《Macromolecular rapid communications》1999,20(3):107-111
The solvent and temperature dependent aggregation of high molecular weight bis[S‐(+)‐3,7‐dimethyloctyl)] substituted poly(p‐phenyleneethynylene) (PPE, 2 ) was examined by absorption, emission and circular dichroism spectroscopy. All herein employed methods strongly support the view that 2 forms ordered aggregates in the solid state and in solvent mixtures. This is the first case in which a chiral high molecular weight PPE displays its aggregation by both optical and chiroptical methods. 相似文献
564.
James F. Ponder Jr. Shawn A. Gregory Amalie Atassi Abigail A. Advincula Joshua M. Rinehart Guillaume Freychet Gregory M. Su Shannon K. Yee John R. Reynolds 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(1):e202211600
Herein, a route to produce highly electrically conductive doped hydroxymethyl functionalized poly(3,4-ethylenedioxythiophene) (PEDOT) films, termed PEDOT(OH) with metal-like charge transport properties using a fully solution processable precursor polymer is reported. This is achieved via an ester-functionalized PEDOT derivative [PEDOT(EHE)] that is soluble in a range of solvents with excellent film-forming ability. PEDOT(EHE) demonstrates moderate electrical conductivities of 20–60 S cm−1 and hopping-like (i.e., thermally activated) transport when doped with ferric tosylate (FeTos3). Upon basic hydrolysis of PEDOT(EHE) films, the electrically insulative side chains are cleaved and washed from the polymer film, leaving a densified film of PEDOT(OH). These films, when optimally doped, reach electrical conductivities of ≈1200 S cm−1 and demonstrate metal-like (i.e., thermally deactivated and band-like) transport properties and high stability at comparable doping levels. 相似文献
565.