2-methyl furan: An experimental study of the excited electronic levels by electron energy loss spectroscopy, vacuum ultraviolet photoabsorption, and photoelectron spectroscopy

Abstract

Articles you may be interested inValence and ionic lowest-lying electronic states of ethyl formate as studied by high-resolution vacuum ultraviolet photoabsorption, He(I) photoelectron spectroscopy, and ab initio calculationsThe electronic states of 1,2,3-triazole studied by vacuum ultraviolet photoabsorption and ultraviolet photoelectron spectroscopy, and a comparison with ab initio configuration interaction methods J. Chem. Phys. 134, 084309 (2011); 10.1063/1.3549812Electronic excitation spectrum of thiophene studied by symmetry-adapted cluster configuration interaction method Electronic excitation and oscillator strength of ethyl bromide by vacuum ultraviolet photoabsorption and electron energy loss spectroscopy Electronic excitation and oscillator strength of ethyl iodide by VUV photoabsorption and electron energy loss spectroscopyThe vacuum ultraviolet absorption spectrum of 2-methyl furan has been recorded between 5 eV ͑248 nm͒ and 9.91 eV ͑125 nm͒ and absolute photoabsorption cross sections measured. The electronic excited states of the molecule have also been probed using high resolution electron energy loss spectroscopy. Recorded under electric-dipole conditions, it has confirmed the magnitude of the photoabsorption cross section values and extended the optical oscillator strength values up to 12 eV. Measurements at several scattering angles have allowed the angular behavior of differential cross section ratios for some features in the 5-7.1 eV region to be measured, which in turn have helped in the assignments of electronic states to observed absorption bands. A high-resolution photoelectron spectrum was measured and allowed the two lowest ionization energies to be determined, these have been used in the identification of the related Rydberg states. Vibrational fine structure in the photoelectron spectrum has also been analyzed. The spectrum is dominated by intense -* transitions. Rydberg series associated with the first and second ionization energies have been identified. The effects of symmetry reduction induced on the furan ring by the methyl substitution are also discussed.

Electronic states of neutral and ionized tetrahydrofuran studied by VUV spectroscopy and ab initio calculations

“…A detailed description of the apparatus can be found elsewhere [33], so only a brief description will be given here. A toroidal dispersion grating is used to select the synchrotron radiation with a FWHM wavelength resolution of approximately 0.075 nm.…”

The electronic states of 2-furanmethanol (furfuryl alcohol) studied by photon absorption and electron impact spectroscopies

“…These are close to corresponding values measured for 2-methylfuran ͑30 and 48 Mb, respectively͒; for the latter, Rydberg-excited states could be positively assigned. 5 Absolute oscillator strengths for furfuryl alcohol, estimated from both the VUV and HREEL spectra, are tabulated in Table III. Agreement between the two data sets is good showing that the optical spectra are free from the line saturation effects or errors due to second-order radiation.…”

“…5 2-methylfuran may be regarded as a precursor of furfuryl alcohol, a H atom in the former being replaced by -OH to give the alcohol. Also, furfuryl alcohol bears the same relation to furan that benzyl alcohol (C 6 H 5 CH 2 OH) does to benzene; the -CH 2 OH group modifies the spectrum of benzene in much the same way as does the methyl group.…”

“…We have already reported on the valence-shell electronic spectroscopy of 2-methylfuran. 5 We now present a comprehensive spectroscopic study on 2-furanmethanol ͑commonly known as furfuryl alcohol͒ the derivative obtained by substitution of an H atom of furan by a CH 2 OH group ͑Fig. 1͒.…”

“…This methodology has been previously used successfully in the case of 2-methylfuran, whose spectrum is remarkably similar to that of furan. 5 Also, it is a method generally applied to substituted aromatics compounds. 10 Little work has been reported on the electronic properties of furfuryl alcohol.…”