Ab initio structural analysis of furylimidazoles

In this study 2-(2(-furyl)-4,5-1H-dihydroimidazole (1) was prepared and then characterized by infrared, Raman, and multidimensional nuclear magnetic resonance (NMR) spectroscopies. The crystal and molecular structures of 1 were determined by X-ray diffraction methods. The density functional theory (DFT) and second-order Møller-Plesset theory (MP2) with Pople's basis set show that there are two conformers for the title molecule that have been theoretically determined in the gas phase, and that only one of them, conformer I, is present in the solid phase. NMR spectra observed for 1 were successfully compared with the calculated chemical shifts at the B3LYP/6-311RRG ** level theorized for this conformer. The harmonic vibrational frequencies for the optimized geometry of the latter conformer were calculated at the B3LYP/6-311RRG ** level in the approximation of the isolated molecule. For a complete assignment of the IR and Raman spectra in the solid phase of 1, DFT calculations were combined with Pulaý s scaled quantum mechanics force field (SQMFF) methodology to fit the theoretical frequency values to the experimental ones.

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“…10 kJ/mol. Similar results have been observed by Vázquez et al 24. for the 2‐(2‐furyl) imidazole molecule.…”

Section: Resultssupporting

confidence: 90%

“…Compounds of this type, especially 2‐arylimino‐imidazolidines, are known for their interaction with α ‐adrenergic receptors 22, 23. In 1997, Vázquez et al 24. presented a theoretical structural and vibrational study on 2‐(2′‐furyl)‐imidazole, in which two conformers of this molecule were predicted.…”

Section: Introductionmentioning

confidence: 99%

Structural and vibrational study of 2‐(2′‐ furyl)‐4,5‐1H‐dihydroimidazole

Zinczuk

Ledesma

Brandán

et al. 2009

J of Physical Organic Chem

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“…The energy difference among them at B3PW91 and B3P86 calculation level are respectively, 1.9 kJ/mol and 1.6 kJ/mol, whereas by using the B3LYP method it is 1.80 kJ/mol. These values are fairly next to those theoretically reported values by Vazquez et al [43] for this compound with the MP2 method (1.3 kJ/mol). These lower values probably indicate the flexibility of the molecular system for the rotation around the O13-C6-N1-C2 dihedral angle.…”

Section: Geometry Optimizationsupporting

confidence: 88%

Synthesis and vibrational analysis of N‐(2′‐Furyl)‐Imidazole

Ledesma

Zinczuk

Altabef

et al. 2009

J Raman Spectroscopy

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The N-(2 -furyl)-imidazole (1) has been prepared and characterized using infrared, Raman and multidimensional nuclear magnetic resonance spectroscopies. Theoretical calculations have been carried out by employing the Density Functional Theory (DFT) method, in order to optimize the geometry of their two conformers in the gas phase and to support the assignments of the vibrational bands of 1 to their normal modes. For a complete assignment of the compound, DFT calculations were combined with Scaled Quamtum Mecanic Force Field (SQMFF) methodology in order to fit the theoretical wavenumber values to the experimental one. Furthermore, Natural Bond Orbital (NBO) and topological properties by Atoms In Molecules (AIM) calculations were performed to analyze the nature and magnitude of the intramolecular interactions. The result reveals that two conformers are expected in liquid phase.

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“…Furthermore, the phenyl ring of 4-phenylimidazole provides a suitable chromophore to examine hydrogen bonding to the imidazole group, and 4-phenylimidazole is itself an enzyme inhibitor. [12] Vázquez et al [13] have presented a theoretical structural and vibrational study on (2 -furyl)-imidazole series, in which the two conformers of the 4-(2 -furyl)-imidazole and 5-(2 -furyl)-imidazole molecules were analyzed using ab initio Hartree-Fock (HF) and second-order perturbation Möller-Plesset (MP2) calculations. In the present work, we report an experimental and theoretical vibrational study of 4(5)-(2 -furyl)-imidazole by means B3LYP calculations using 6-31G * and 6-311++G * * basis sets.…”

Section: Introductionmentioning

confidence: 99%

Structural, vibrational spectra and normal coordinate analysis for two tautomers of 4(5)‐(2′‐furyl)‐imidazole

Ledesma

Zinczuk

González

et al. 2009

J Raman Spectroscopy

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We have synthesized both the 4 and 5 tautomeric forms of 4(5)-(2 -furyl)-imidazole (1) and investigated their molecular vibrations by infrared and Raman spectroscopies as well as by calculation based on the density functional theory (DFT) approach. Examination of the temperature dependence of IR intensity revealed the band characteristics of the 4 and 5 tautomers of (1). Comparison of experimental and calculated chemical shifts in nuclear magnetic resonance (NMR) spectroscopy was made in order to identify the two tautomeric forms. The assignment of vibrational normal modes was performed, and the force field obtained reproduced the experimental vibrational wavenumbers with a root mean-square deviation (RMSD) value of ca. 13 cm −1 for both tautomers. The natural bond orbital (NBO) study reveals the characteristics of the electronic delocalization of the two tautomeric structures.

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Ab initio structural analysis of furylimidazoles

Cited by 4 publications

References 32 publications

Structural and vibrational study of 2‐(2′‐ furyl)‐4,5‐1H‐dihydroimidazole

Structural and vibrational study of 2‐(2′‐ furyl)‐4,5‐1H‐dihydroimidazole

Synthesis and vibrational analysis of N‐(2′‐Furyl)‐Imidazole

Structural, vibrational spectra and normal coordinate analysis for two tautomers of 4(5)‐(2′‐furyl)‐imidazole

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