Unusual H-Bond Topology and Bifurcated H-bonds in the 2-Fluoroethanol Trimer.
By using a combination of rotational spectroscopy and ab initio calculations, an unusual H-bond topology was revealed for the 2-fluoroethanol trimer. The trimer exhibits a strong heterochiral preference and adopts an open OH⋅⋅⋅OH H-bond topology while utilizing two types of bifurcated H-bonds involving organic fluorine. This is in stark contrast to the cyclic OH⋅⋅⋅OH H-bond topology adopted by trimers of water and other simple alcohols. The strengths of different H-bonds in the trimer were analyzed by using the quantum theory of atoms in molecules. The study showcases a remarkable example of a chirality-induced switch in H-bond topology in a simple transient chiral fluoroalcohol. It provides important insight into the H-bond topologies of small fluoroalcohol aggregates, which are proposed to play a key role in protein folding and in enantioselective reactions and separations where fluoroalcohols serve as a (co)solvent.
Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada).
Javix
J
Thomas
School of Mechanical Engineering, Shanghai Jiao Tong University, No.800 Dong Chuan Road, Shanghai, 200240 (P.R. China).
Xunchen
X
Liu
Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada).
Wolfgang
W
Jäger
Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada). yunjie.xu@ualberta.ca.
Yunjie
Y
Xu
H-bond topology; bifurcated H-bonds; chirality; fluoroalcohols; rotational spectroscopy