Solvent-assisted conformational isomerization (SACI) of meta-substituted phenols: Tuning relative stability, isomerization barrier, and IVR rate

Sohn, Woon Yong; Cho, Keun-Jin; Lee, So Young; Kang, Sung Sik; Park, Young Dong; Kang, Hyuk

doi:10.1016/j.cplett.2012.01.004

Cited by 17 publications

(11 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The identification of at least three homochiral dimers in enantiopure CD expansions and their similarly strong counterparts in ED further ruled out major contributions from an intramolecular racemisation mechanism triggered by the dimerisation energy. 75,76 Computations suggested that the visibility of most homochiral dimer isomers is also not significantly inferior to that of the heterochiral global minimum structure. What remains as an explanation is the spreading of homochiral spectral transition intensity over at least three conformations in combination with partial overlap with the heterochiral bands.…”

Section: Discussionmentioning

confidence: 99%

The reduced cohesion of homoconfigurational 1,2-diols

Hartwig

Lange

Poblotzki

et al. 2020

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

By a combination of linear FTIR and Raman jet spectroscopy, racemic trans-1,2-cyclohexanediol is shown to form an energetically unrivalled S 4 -symmetric heterochiral dimer in close analogy to 1,2-ethanediol.Analogous experiments with enantiopure trans-1,2-cyclohexanediol reveal the spectral signature of at least three unsymmetric homochiral dimers. A comparison to signal-enhanced spectra of 1,2-ethanediol and to calculations uncovers at least three transiently homochiral dimer contributions as well. In few of these dimer structures, the intramolecular OHÁ Á ÁO contact present in monomeric 1,2-diols survives, despite the kinetic control in supersonic jet expansions. This provides further insights into the dimerisation mechanism of conformationally semi-flexible molecules in supersonic jets. Racemisation upon dimerisation is shown to be largely quenched under jet cooling conditions, whereas it should be strongly energy-driven at higher temperatures. The pronounced energetic preference for heterochiral aggregation of vicinal diols is also discussed in the context of chirality-induced spin selectivity. † Electronic supplementary information (ESI) available: Interactive and static structures, tables of experimental and computational details, energy diagrams for different levels of calculation, and additional experimental spectra. See

show abstract

Section: Discussionmentioning

confidence: 99%

The reduced cohesion of homoconfigurational 1,2-diols

Hartwig

Lange

Poblotzki

et al. 2020

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…Correlatively, its large mass and polarisability make it an active solvent, which favours interconversion between conformations, leading to a better conformational relaxation. Such an effect has been revealed in the presence of solvent molecules in the expansion, leading to the concept of "solvent-assisted conformational isomerisation" [182,183]. As a matter of fact, using He or Ne instead of Ar as carrier gas enables the observation of additional minor species calculated at high energy [58,112], in agreement with the usual picture of the supersonic expansion being a rapid event, which freezes the conformational distributions at high temperature (kinetic trapping) [184].…”

Section: Lessons From the Confrontation mentioning

confidence: 98%

Isolated Neutral Peptides

Gloaguen

Mons

2014

Topics in Current Chemistry

View full text Add to dashboard Cite

This chapter examines the structural characterisation of isolated neutral amino-acids and peptides. After a presentation of the experimental and theoretical state-of-the-art in the field, a review of the major structures and shaping interactions is presented. Special focus is made on conformationally-resolved studies which enable one to go beyond simple structural characterisation; probing flexibility and excited-state photophysics are given as examples of promising future directions.

show abstract

“…Ap rerequisite is the easy exchange between the solvation sites,that is,the absence of major isomerization barriers. [2] Thew ell-studied anisole molecule [1,[3][4][5][6] may be viewed as an electron-rich benzene derivative or as an electron-depleted ether. Theu nderlying mesomeric effect makes the two hydrogen-bond docking sites,n amely the oxygen (O) and the p cloud, similarly attractive.…”

mentioning

confidence: 99%

Control over the Hydrogen‐Bond Docking Site in Anisole by Ring Methylation

et al. 2015

View full text Add to dashboard Cite

The supramolecular docking of methanol to anisole may occur via an OH⋅⋅⋅O hydrogen bond or via an OH⋅⋅⋅π contact. The subtle balance between these two structures can be varied in supersonic jets by one order of magnitude through single to triple methylation of the aromatic ring and introduction of a single tert-butyl substituent, as evidenced by infrared spectroscopy. This steep variation makes it possible to assess the accuracy of relative quantum-chemical energy predictions on a kJ mol(-1) level, promising insights into inductive, mesomeric, and dispersive effects. The zero-point-corrected B3LYP-D3/aVTZ level is shown to provide an accurate relative description of the two very different hydrogen bonds, similar to a wavefunction-based protocol including CCSD(T) corrections applied to the same structures. M06-2X alone systematically overestimates the stability of π coordination.

show abstract

Solvent-assisted conformational isomerization (SACI) of meta-substituted phenols: Tuning relative stability, isomerization barrier, and IVR rate

Cited by 17 publications

References 39 publications

The reduced cohesion of homoconfigurational 1,2-diols

The reduced cohesion of homoconfigurational 1,2-diols

Isolated Neutral Peptides

Control over the Hydrogen‐Bond Docking Site in Anisole by Ring Methylation

Contact Info

Product

Resources

About