Premium
Conformational equilibria of TADDOL‐s in solution investigated by vibrational circular dichroism
Author(s) -
Uncuta Cornelia,
Bartha Emeric,
Gherase Dragos,
Teodorescu Florina,
Draghici Constantin,
Cavagnat Dominique,
Daugey Nicolas,
Liotard Daniel,
Buffeteau Thierry
Publication year - 2010
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20829
Subject(s) - chemistry , intramolecular force , vibrational circular dichroism , conformational isomerism , hydrogen bond , substituent , crystallography , chirality (physics) , enantiomer , absolute configuration , density functional theory , circular dichroism , stereochemistry , computational chemistry , molecule , nambu–jona lasinio model , chiral symmetry breaking , physics , organic chemistry , quantum mechanics , quark
Six enantiomeric pairs of TADDOL‐s gathered in two series with either methyl (series A ) or phenyl (series B ) substituent in 2‐position of the dioxolane ring were studied by vibrational circular dichroism (VCD). Experimental IR and VCD spectra associated with density functional theory (DFT) calculations showed that the two series exhibit quite different conformations in solution. In series A , the conformer with anti CO bonds and stabilized by intramolecular OH⋅⋅⋅OH hydrogen bonding prevails, whereas in series B the conformer with gauche CO bonds and intramolecular OH⋅⋅⋅π hydrogen bonding is favored. The shape and sign of the VCD bands in the OH stretching region revealing the nature of the intramolecular hydrogen bonding were clearly identified. Polarimetric measurements showed that, within the same absolute configuration, compounds in series A and in series B have opposite signs of optical rotation. Chirality 2010. © 2010 Wiley‐Liss, Inc.