Lock‐and‐Key Principle on a Microscopic Scale: The Case of the Propylene Oxide⋅⋅⋅Ethanol Complex

Abstract

Molekulare Erkennung: Die Bindung zwischen Ethanol und Propylenoxid (PO) ähnelt dem Schlüssel‐Schloss‐Prinzip, wobei (R)‐PO das starre Schloss und die (G−)‐, (G+)‐ und T‐Konformere von EtOH die unterschiedlichen Schlüssel sind (siehe Bild; C gelb, O rot). Die Analyse von sechs wasserstoffbrückengebundenen PO⋅⋅⋅EtOH‐Konformeren mithilfe von Rotationsspektroskopie und Ab‐initio‐Rechnungen zeigt, welcher EtOH‐Schlüssel am besten in das PO‐Schloss passt.

Chirality Recognition in the Glycidol⋅⋅⋅Propylene Oxide Complex: A Rotational Spectroscopic Study

“…A comparison of the experimental and calculated rotational constants shows a maximum deviation of 2.3 %, which is comparable to deviations of 1.1-6.3 % found in PO···2-fluoroethanol [9] and PO···ethanol. [10] This indicates that the predicted structures are quite close to the ones determined from experiment.…”

Perfluorobutyric Acid and Its Monohydrate: A Chirped Pulse and Cavity Based Fourier Transform Microwave Spectroscopic Study

“…Two of the minimum structures are mirror images of each other and cannot be superimposed onto each other, that is, the molecule possesses the property of transient chirality. [22] Because the type of rotational spectroscopy used here cannot discriminate between enantiomers, we consider them as one conformer in the remainder of the article and discuss potential splittings of rotational transitions in terms of a tunnelling motion between two equivalent geometries. The relative dissociation energies, rotational constants, and the electric dipole moment components for the PFBA conformers are listed in Table 1.…”

Hydration of a Chiral Molecule: The Propylene Oxide⋅⋅⋅(Water)2 Cluster in the Gas Phase

“…Rather, the main discriminating factors in PO···(H 2 O) 2 are maximizing the interactions between the second H 2 O and PO, and between the water molecules. The [8] 157.0 156.4 --178.4…”

“…[6] Very recently, the rotational spectra of a number of PO-containing chiral molecular complexes have been studied, and detailed information about the structures of conformers and their relative stability ordering was reported. [7][8][9] One of the systems studied is the PO···H 2 O binary complex, where both syn and anti PO···H 2 O were detected experimentally. [7] While this experimental result represents a significant step towards understanding the intermolecular interactions taking place in an aqueous environment, there is still a huge gap to bridge between the isolated binary PO···H 2 O complex and PO in water.…”

“…The energy difference caused by the binding dissimilarity on the syn and the anti sides of PO is defined as the diastereofacial discrimination energy, [7,8] D 0 (syn)ÀD 0 (anti). This value is about À0.73 kJ mol À1 for PO···(H 2 O) 2 .…”