Strong Intramolecular Hydrogen Bonds and steric Effects involving C=S groups. An NMR and Computational Study.

Rita S. Elias, Bahjat A. Saaed, Fadhil S. Kamounah, Fritz Duus, Poul Erik Hansen

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

A number of 5-acyl rhodanines and thiorhodanines with bulky acyl groups (pivaloyl and adamantoyl), not previously available, have been synthesized. The compounds are shown to exist at the enol form. Structures have been calculated using both the MP2 approach and the B3LYP-GD3BJ functional and the 6-311++G(d,p) basis set. Hydrogen bond energies are estimated by subtracting energies of a structure with the OH group turned 180o from that of the intramolecularly hydrogen bonded one. Properties such as OH chemical shifts, two-bond isotope effects on 13C chemical shifts, electron densities at the bond critical point from AIM analysis, as well as the hydrogen bond energies show that the sterically hindered compounds have stronger hydrogen bonds than methyl or isopropyl derivatives. The combination of oxygen and sulphur derivatives enables a detailed analysis of hydrogen bond energies.
OriginalsprogEngelsk
TidsskriftMagnetic Resonance in Chemistry
ISSN0749-1581
StatusUdgivet - 1 nov. 2019

Emneord

  • Intramolecular hydrogen bonding
  • isotope effects
  • steric effects
  • adamantane derivatives
  • thiorhodanines

Citer dette

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title = "Strong Intramolecular Hydrogen Bonds and steric Effects involving C=S groups. An NMR and Computational Study.",
abstract = "A number of 5-acyl rhodanines and thiorhodanines with bulky acyl groups (pivaloyl and adamantoyl), not previously available, have been synthesized. The compounds are shown to exist at the enol form. Structures have been calculated using both the MP2 approach and the B3LYP-GD3BJ functional and the 6-311++G(d,p) basis set. Hydrogen bond energies are estimated by subtracting energies of a structure with the OH group turned 180o from that of the intramolecularly hydrogen bonded one. Properties such as OH chemical shifts, two-bond isotope effects on 13C chemical shifts, electron densities at the bond critical point from AIM analysis, as well as the hydrogen bond energies show that the sterically hindered compounds have stronger hydrogen bonds than methyl or isopropyl derivatives. The combination of oxygen and sulphur derivatives enables a detailed analysis of hydrogen bond energies.",
keywords = "Intramolecular hydrogen bonding, isotope effects, steric effects, adamantane derivatives, thiorhodanines",
author = "Elias, {Rita S.} and Saaed, {Bahjat A.} and Kamounah, {Fadhil S.} and Fritz Duus and Hansen, {Poul Erik}",
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month = "11",
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language = "English",
journal = "Magnetic Resonance in Chemistry",
issn = "0749-1581",
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Strong Intramolecular Hydrogen Bonds and steric Effects involving C=S groups. An NMR and Computational Study. / Elias, Rita S.; Saaed, Bahjat A.; Kamounah, Fadhil S.; Duus, Fritz; Hansen, Poul Erik.

I: Magnetic Resonance in Chemistry, 01.11.2019.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Strong Intramolecular Hydrogen Bonds and steric Effects involving C=S groups. An NMR and Computational Study.

AU - Elias, Rita S.

AU - Saaed, Bahjat A.

AU - Kamounah, Fadhil S.

AU - Duus, Fritz

AU - Hansen, Poul Erik

PY - 2019/11/1

Y1 - 2019/11/1

N2 - A number of 5-acyl rhodanines and thiorhodanines with bulky acyl groups (pivaloyl and adamantoyl), not previously available, have been synthesized. The compounds are shown to exist at the enol form. Structures have been calculated using both the MP2 approach and the B3LYP-GD3BJ functional and the 6-311++G(d,p) basis set. Hydrogen bond energies are estimated by subtracting energies of a structure with the OH group turned 180o from that of the intramolecularly hydrogen bonded one. Properties such as OH chemical shifts, two-bond isotope effects on 13C chemical shifts, electron densities at the bond critical point from AIM analysis, as well as the hydrogen bond energies show that the sterically hindered compounds have stronger hydrogen bonds than methyl or isopropyl derivatives. The combination of oxygen and sulphur derivatives enables a detailed analysis of hydrogen bond energies.

AB - A number of 5-acyl rhodanines and thiorhodanines with bulky acyl groups (pivaloyl and adamantoyl), not previously available, have been synthesized. The compounds are shown to exist at the enol form. Structures have been calculated using both the MP2 approach and the B3LYP-GD3BJ functional and the 6-311++G(d,p) basis set. Hydrogen bond energies are estimated by subtracting energies of a structure with the OH group turned 180o from that of the intramolecularly hydrogen bonded one. Properties such as OH chemical shifts, two-bond isotope effects on 13C chemical shifts, electron densities at the bond critical point from AIM analysis, as well as the hydrogen bond energies show that the sterically hindered compounds have stronger hydrogen bonds than methyl or isopropyl derivatives. The combination of oxygen and sulphur derivatives enables a detailed analysis of hydrogen bond energies.

KW - Intramolecular hydrogen bonding

KW - isotope effects

KW - steric effects

KW - adamantane derivatives

KW - thiorhodanines

M3 - Journal article

JO - Magnetic Resonance in Chemistry

JF - Magnetic Resonance in Chemistry

SN - 0749-1581

ER -