Rapid probe of the nicotine spectra by high-resolution rotational spectroscopy

Abstract

Nicotine has been investigated in the gas phase and two conformational forms were characterized through their rotational spectra. Two spectroscopic techniques have been used to obtain the spectra: a new design of broadband Fourier transform microwave (FTMW) spectroscopy with an in-phase/quadrature-phase-modulation passage-acquired-coherence technique (IMPACT) and narrowband FTMW spectroscopy with coaxially oriented beam-resonator arrangement (COBRA). The rotational, centrifugal distortion and hyperfine quadrupole coupling constants of two conformers of nicotine have been determined and found to be in N-methyl trans configurations with the pyridine and pyrrolidine rings perpendicular to one another. The quadrupole hyperfine structure originated by two 14 N nuclei has been completely resolved for both conformers and used for their unambiguous identification.

Rapid capture of large amplitude motions in 2,6-difluorophenol: High-resolution fast-passage FT-MW technique

“…The spectra were obtained using the IMPACT-FT-MW spectrometer in Hannover and was constructed in parallel to a similar instrument located at the University of Valladolid [14]. Direct use of a commercial sample of 2,6-difluorophenol, without any further purification, was made.…”

Microwave Spectroscopy of Biomolecular Building Blocks

“…Microwave spectroscopy has long been considered to be a powerful method for precise determination of gas-phase structures, being the source of the majority of gas-phase structural data known nowadays [13,14] (see, for example, the Landolt-Börnstein, New Series II series). The combination of Fourier transform microwave spectroscopy with supersonic jets has given rise to two different families of techniques: those using a narrow band molecular beam (MB-FTMW) [15][16][17] or, more recently developed, wide band chirped pulse FTMW spectroscopy (CP-FTMW [18] and IMPACT-FTMW [19]). By virtue of the extremely high resolution (sub-Doppler) and sensitivity of the FTMW techniques, all populated species in the jet, be they tautomers, conformers, or isotopomers, can be analyzed independently.…”

“…This new approach increases the speed of the spectral acquisition, making the search of the different coexisting species in the jet much more efficient. In the last few years, a new alternative design of broadband Fourier transform microwave spectroscopy, called IMPACT (in-phase/quadrature-phase modulation passage acquired coherence technique) has been developed in our laboratory [19]. The aforementioned broadband techniques have been combined with a laser ablation source for the study of solid biomolecules [63,64].…”

A broadband Fourier-transform microwave spectrometer with laser ablation source: The rotational spectrum of nicotinic acid

“…This new approach increases the speed of the spectral acquisition, making the search of the different coexisting species in the jet much more efficient. Recently, we have developed a new alternative design of broadband Fourier transform microwave spectroscopy called IMPACT (in-phase/quadrature-phase modulation passage acquired coherence technique), which has been used in the study of nicotine [9].…”