Structural information on the S and S1 state of o-fluorophenol by hole burning and high resolution ultraviolet spectroscopy

Abstract

The electronic transitions of o-fluorophenol situated at 36 799.382 cm Ϫ1 and 36 906.710 cm Ϫ1 , denoted the A and B bands, respectively, have been investigated by high resolution fluorescence excitation spectroscopy. Hole burning studies together with the high resolution spectroscopy results show that both bands originate in the same ground state and can be fitted to the rotational constants of the cis isomer. The rotational constants for the excited states are found to be AЈϭ3231.795 MHz, BЈϭ2207.92 MHz and CЈϭ1313.97 MHz for the A band and AЈϭ3226.945 MHz, BЈϭ2211.24 MHz and CЈϭ1321.03 MHz for the B band. The planarity of the ground state is lost upon electronic excitation, which enhances the activity of an out-of-plane vibration. The A and B band transitions arise from excitations to respectively the zero and first overtone levels in the double-minimum potential of this out-of-plane vibration, which shows similarities to the so-called butterfly mode observed in other benzene derivatives.

A Multipronged Comparative Study of the Ultraviolet Photochemistry of 2-, 3-, and 4-Chlorophenol in the Gas Phase

“…2(b) shows the time-dependent 2-FPhOH + parent ion signal obtained when exciting 2-fluorophenol (2-FPhOH, predominantly if not exclusively its syn-conformer) at its S1-S0 origin (pump = 272 nm) and ionising at probe = 243.1 nm. This study returns a 2-FPhOH(S1) lifetime  = 2.3±0.2 ns, in reasonable accord with previous estimates from high resolution linewidth studies of the syn-conformer ( = 4.60.2 ns and 2.8±0.2 ns 31 ) and similar to that found when exciting bare phenol at its S1-S0 origin. 5,30 As with phenol, the 2-FPhOH(S1) decay time constant was seen to decrease on tuning to shorter excitation wavelengths (e.g.…”

Spectroscopic Investigation of cis-2,4-Difluorophenol Cation by Mass-analyzed Threshold Ionization Spectroscopy

“…13 With help from theoretical calculations, they proposed that that presence of an intramolecular OH F bonding preferentially stabilizes the cis conformer of 24DFP, as that observed in 2-fluorophenol. 8,12,14 A similar observation has been reported for 2-fluorophenol 14 and 2-chlorophenol. 35 We have performed the Becke three-parameter with the PW91 correlation functional (B3PW91) calculations with the 6-311++G(d,p) basis set to investigate the stable rotamers Figure 4.…”

“…[1][2][3] Many fluorinated benzene derivatives, [4][5][6][7][8][9][10][11][12][13][14][15][16] are extensively studied by various spectroscopic methods. 2-Fluorophenol is regarded as one of the classic example of intramolecular hydrogen-bonding systems which have been the subject of various studies.…”

“…2-Fluorophenol is regarded as one of the classic example of intramolecular hydrogen-bonding systems which have been the subject of various studies. [6][7][8][9][10][11][12] Chakrabarti et al applied radiofrequency-microwave double resonance (RFMWDR) and conventional microwave spectroscopic techniques to record the microwave rotational spectra of gas-phase 2,4-difluorophenol (24DFP) in the ground S 0 state. 13 They proposed that the cis and trans rotamers of 24DFP coexist and possess the intramolecular OH F bonding, as that observed in 2-fluorophenol.…”

“…13 They proposed that the cis and trans rotamers of 24DFP coexist and possess the intramolecular OH F bonding, as that observed in 2-fluorophenol. 8,12,14 In addition, the cis form is more abundant than the trans form. Anbarasan and coworkers recorded the infrared and Raman spectra of 24DFP in the condensed phase and reported the active vibrations of this molecule in the S 0 state.…”