This paper studies supersonic jet-cooled 1-fluoronaphthalene (1FN) clusters by ultraviolet (UV) laser ionization at 281 nm in a time-of-flight mass spectrometer. The (1FN)+ (n=1-3) series cluster ions are obs...This paper studies supersonic jet-cooled 1-fluoronaphthalene (1FN) clusters by ultraviolet (UV) laser ionization at 281 nm in a time-of-flight mass spectrometer. The (1FN)+ (n=1-3) series cluster ions are observed where the signal intensity decreases with increasing cluster size. The effects of sample inlet pressures and ionization laser fluxes to mass spectral distribution are measured. Using density functional theory calculations, it obtains a planar geometric structure of 1FN dimer which is combined through two hydrogen bonds. The mass spectra indicate that the intensity of 1FN trimer is much weaker than that of 1FN dimer and this feature is attributed to the fact that the dimer may form the first "shell" in geometric structure while the larger clusters are generated based on this fundamental unit.展开更多
The one-colour resonant two-photon ionization (R2PI) spectrum of the 1-fluoronaphthalene (1FN) dimer has been studied in the wavelength range of 304 to 322 nm by using a supersonic molecular beam and time-of-fligh...The one-colour resonant two-photon ionization (R2PI) spectrum of the 1-fluoronaphthalene (1FN) dimer has been studied in the wavelength range of 304 to 322 nm by using a supersonic molecular beam and time-of-flight mass spectrometry. Compared with the original band 00^0 (at 313.8 nm) of the S1 ← So transition of the 1FN monomer, a red-shifted band was observed in the 1FN dimer spectrum at about 315 nm with a relatively large linewidth, nearly 2 nm. Based on the consideration of inductive effect and ab initio calculations, this red-shifted band is assigned to the first electronic excited transition of the 1FN dimer. A possible geometric structure of the 1FN dimer is also obtained with calculations that the two 1FN molecules are combined through two hydrogen bonds which are formed between the hydrogen atom of a molecule and the fluorine atom of a neighbouring molecule. A time-dependent calculation was also carried out and the results are consistent with the experimental data.展开更多
文摘This paper studies supersonic jet-cooled 1-fluoronaphthalene (1FN) clusters by ultraviolet (UV) laser ionization at 281 nm in a time-of-flight mass spectrometer. The (1FN)+ (n=1-3) series cluster ions are observed where the signal intensity decreases with increasing cluster size. The effects of sample inlet pressures and ionization laser fluxes to mass spectral distribution are measured. Using density functional theory calculations, it obtains a planar geometric structure of 1FN dimer which is combined through two hydrogen bonds. The mass spectra indicate that the intensity of 1FN trimer is much weaker than that of 1FN dimer and this feature is attributed to the fact that the dimer may form the first "shell" in geometric structure while the larger clusters are generated based on this fundamental unit.
基金supported by the Doctoral Special Fund of Qufu Normal University of China
文摘The one-colour resonant two-photon ionization (R2PI) spectrum of the 1-fluoronaphthalene (1FN) dimer has been studied in the wavelength range of 304 to 322 nm by using a supersonic molecular beam and time-of-flight mass spectrometry. Compared with the original band 00^0 (at 313.8 nm) of the S1 ← So transition of the 1FN monomer, a red-shifted band was observed in the 1FN dimer spectrum at about 315 nm with a relatively large linewidth, nearly 2 nm. Based on the consideration of inductive effect and ab initio calculations, this red-shifted band is assigned to the first electronic excited transition of the 1FN dimer. A possible geometric structure of the 1FN dimer is also obtained with calculations that the two 1FN molecules are combined through two hydrogen bonds which are formed between the hydrogen atom of a molecule and the fluorine atom of a neighbouring molecule. A time-dependent calculation was also carried out and the results are consistent with the experimental data.