(<i>Z</i>)-6-[(2-Fluorophenyliminio)methylene]-2,3-dihydroxyphenolate

Petek, Hande; Albayrak, Çiğdem; Ağar, Erbil; Kalkan, Hüseyin

doi:10.1107/s1600536806029606

Cited by 21 publications

(23 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although SA derivative reported here is in NH form, its geometric parameters are deviate from their relevant values. These differentiations in certain bond distances can be explained by the resonance effect between two canonical structures, the cis-keto tautomer and zwitterionic form [5,12,13]. Throughout solid-state tautomerization, the proton initially attached to O1 is transferred to N1 by forming N-HÁÁÁO type resonance-assisted H-bond (RAHB) whose details are given in Table 3, thereby introducing with appreciable keto character to the C13-O1 bond and partial double bond character to the C7-C8 due to the resonance effect mentioned before.…”

Section: Resultsmentioning

confidence: 97%

“…and C-O -, are not as distinctive as indicators as is the N ? -H bond, because their molecular structures in the solid state can be regarded as a resonance hybrid of two canonical structures, cis-keto tautomer and zwitterionic form [5,12] (Chart 1a). The predominance of the zwitterionic over NH canonic form of Schiff bases can be discerned from details of their molecular geometries [13].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Structural and aromatic aspects for tautomerism of (Z)-6-((4-bromophenylamino)methylene)-2,3-dihydroxycyclohexa-2,4-dienone

et al. 2009

Self Cite

View full text Add to dashboard Cite

The molecular and crystal structure of (Z)-6-((4-bromophenylamino)methylene)-2,3-dihydroxycyclohexa-2,4-dienone were determined by single crystal X-ray diffraction and spectroscopic methods. Molecules of the compound can be regarded as a resonance hybrid of cisketo tautomer and zwitterionic form. Pairs of molecules of the compound generate pseudocyclic centrosymmetric R 2 2 ð10Þ supramolecular synthons with the aid of O-HÁÁÁO type intermolecular H-bonds. Stacking of R 2 2 ð10Þ synthons along b-axis is stabilized by pÁÁÁp interactions. Changes in both covalent topology and molecular geometry of the compound accompanying proton transfer were monitored by a relaxed PES scan with respect to hydroxyl bond length used as redundant internal coordinate. Quantum chemical studies at 6-311 ? G(d,p) level reveal that bond lengths which are indicative to tautomerization process cannot reach their expected values even if proton transfer occurs in gas phase and pseudo-aromatic chelate ring formation has primary effect on the stabilization of NH tautomer.Resonance-assisted intramolecular H-bond affects the electronic state of its neighboring aromatic fragments.

show abstract

Section: Resultsmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Structural and aromatic aspects for tautomerism of (Z)-6-((4-bromophenylamino)methylene)-2,3-dihydroxycyclohexa-2,4-dienone

et al. 2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…Zwitterionic forms are easily distinguishable from the other NH forms, since N ? -H bonds are longer than the standard interatomic separations observed in neutral N-H bonds (0.87 Å ) [9,[11][12][13]. The other ionic bonds in the zwitterions, C-O -and C=N ?…”

Section: Introductionmentioning

confidence: 86%

The proton transfer process observed in the structure analysis and DFT calculations of (E)-2-ethoxy-6-[(2-methoxyphenylimino)methyl]phenol

et al. 2010

Self Cite

View full text Add to dashboard Cite

The crystal and molecular structures of an o-hydroxy Schiff base derivative, (E)-2-ethoxy-6-[(2-methoxyphenylimino)methyl]phenol, have been determined by single crystal X-ray diffraction analyses at 296 and 100 K. The results from temperature-dependent structural analysis regarding the tautomeric equilibrium of the compound were interpreted with the aid of quantum chemical calculations. To clarify the tautomerization process and its effects on the molecular geometry, the gasphase geometry optimizations of two possible tautomers of the title molecule, its OH and NH form, were achieved using DFT calculations with B3LYP method by means of 6-31 ? G(d,p) basis set. In order to describe the potential barrier belonging to the phenolic proton transfer, nonadiabatic Potential Energy Surface (PES) scan was performed based on the optimized geometry of the OH tautomeric form by varying the redundant internal coordinate, O-H bond distance. The Harmonic Oscillator Model of Aromaticity (HOMA) indices were calculated in every step of the scan process so as to express the deformation in the aromaticities of principal molecular moieties of the compound. The results show that there is a dynamic equilibrium between the aromaticity level of phenol and chelate ring and furthermore p-electron coupling affecting overall molecule of the title compound. Charge transfer from phenol ring to pseudo-aromatic chelate ring increases with increasing temperature, whereas p-electron transfer from chelate ring to anisole ring is decreased as temperature increases. The most strength intramolecular H-bonds are observed for conformers close to transition state.

show abstract

“…The cis-quinoid and zwitterionic forms are not just resonance structures of each other, they can also exist separately. The zwitterionics can differ from cis-quinoid NH forms with their ionic N + -H bond distances and aromaticity of the rings [26][27][28]. The tautomeric forms and observed strong intramolecular hydrogen bonds depending on these forms can be seen in Fig.…”

Section: Introductionmentioning

confidence: 92%

Molecular structure of (Z)-6-[(5-chloro-2-hydroxyphenylamino) methylene]-3-(diethylamino)cyclohexa-2,4-dienone: A combined experimental and theoretical study

Koşar

Albayrak

Odabaşoğlu

et al. 2011

Journal of Molecular Structure

Self Cite

View full text Add to dashboard Cite

(Z)-6-[(2-Fluorophenyliminio)methylene]-2,3-dihydroxyphenolate

Abstract: Key indicatorsSingle-crystal X-ray study T = 296 K Mean (C-C) = 0.003 Å R factor = 0.051 wR factor = 0.124 Data-to-parameter ratio = 10.2 For details of how these key indicators were automatically derived from the article, see

Cited by 21 publications

References 7 publications

Structural and aromatic aspects for tautomerism of (Z)-6-((4-bromophenylamino)methylene)-2,3-dihydroxycyclohexa-2,4-dienone

Structural and aromatic aspects for tautomerism of (Z)-6-((4-bromophenylamino)methylene)-2,3-dihydroxycyclohexa-2,4-dienone

The proton transfer process observed in the structure analysis and DFT calculations of (E)-2-ethoxy-6-[(2-methoxyphenylimino)methyl]phenol

Molecular structure of (Z)-6-[(5-chloro-2-hydroxyphenylamino) methylene]-3-(diethylamino)cyclohexa-2,4-dienone: A combined experimental and theoretical study

Contact Info

Product

Resources

About