Ion cyclotron resonance mass spectroscopy

Until this point, results appear to be rather divergent, possibly because these studies were performed on SMA dissolved in various solvents and solvation might modify the distribution of electrons in the Si-C-N unit. In order to circumvent this problem, gas phase studies and theoretical approaches were developed. In the gas phase (ion cyclotron resonance mass spectroscopy), trimethylsilylmethyldimethylamine was reported to be more basic than the analogous neopentyldimethylamine from proton affinity measurements based upon proton affinity of ammonia (201.0 kcal/mol) 227.1 and 225.8 kcal/mol respectively.32 Conversely, the ionization potential of MSMA indicates a basicity lower than that of its carbon analog and the authors emphasize the fact that this result is opposite... 

In practice, one equidistantly discretizes (digitizes) the continuous (analog) time variable t as t = tn = nAt = nr (n = 0,1,2,..., N — 1), where the nonnegative integer n counts the time. The quantity r is the time increment (the time lag) or the sampling time, which is also called the dwell time r = T/N in ion cyclotron resonance mass spectroscopy (ICRMS) [44], Hereafter, we shall write ... 

Another example is a recent study of proton affinities of a furan, methylphenols and related anisoles by van Beelen et al. [87]. The proton affinities were determined by ion cyclotron resonance mass spectroscopy and theoretically by G3(MP2) theory. The G3(MP2) proton affinity provided support for revision of the proton affinity of furan... 

Comisarow, M.B. Marshall, A.G. Fourier transform ion cyclotron resonance mass spectroscopy. Chem. Phys. Lett. 1974, 25, 282-283. 

Perfluoroethylenes have been characterized by desorption chemical ionization and tandem mass spectrometry Fourier transform ion cyclotron resonance mass spectroscopy has also been applied to the identification of polymers, eg. polyethylene glycols. Comparative complimentary plasma desorption mass spectrometry/secondary ion mass spectrometry has been applied to the identification of oligomers of various polymers including polyethylene glycol, polytetrafluoroethylene, polycarbonate, polyacrylates, polyethylene terephthalate and siloxanes. ... 

A relatively unknown technique (laser desorption fourier transform ion cyclotron resonance mass spectroscopy) has been used (397) to identify dyes in plastics such as polymethylmethacrylate. A detection limit of 0.1% was obtained, which compared with a limit of 1-2% using an ATR infrared spectroscopy technique. 

Fourier transform ion cyclotron resonance mass spectrometry (FTIC-MS), 155 of ionic clusters, 172-173 FTIR spectroscopy, 191-192... 

Note The acronyms used here are OSPED (optical spectroscopy in a pulsed electrical discharge), FAMS (flowing afterglow mass spectrometry), SIFT (selected ion flow tube), TRAPI (time-resolved atmospheric pressure ionization mass spectrometry), PHPMS (pulsed high-pressure ionization mass spectrometry), ICRMS (ion cyclotron resonance mass spectrometry), and ADO (averaged dipole orientation collision rate theory). 

Attempts have been made to observe and experimentally determine the structure of CH5+ in the gas phase and study it in the condensed state using IR spectroscopy,764 765 pulse electron-beam mass spectrometry,766 and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS).767 However, an unambiguous structure determination was unsuccessful. Retardation of the degenerate rearrangement was achieved by trapping the ion in clusters with H2, CH4, Ar, or N2. 

Tremblay, L. B., Dittmar,T., Marshall, A. G., Cooper, W. J., and Cooper, W.T. (2007). Molecular characterization of dissolved organic matter in a North Brazilian mangrove porewater and mangrove-fringed estuaries by ultrahigh resolution Fourier transform-ion cyclotron resonance mass spectrometry and excitation/emission spectroscopy. Marine Chem. 105, 15-29. 

Many heterocycles, for instance NH-azoles, have acid-base properties of either or both proton gain (basicity) and proton loss (acidity) [85], The possibility of studying such processes in the gas-phase (mass spectrometry and Fourier transform ion cyclotron resonance - FTICR - spectroscopy) provides theoreticians with values... 

Owing to its stability, solubility, and highly reproducible oxidation behavior, ferrocene has long been used as an electrochemical standard in nonaqueous solvents. Not surprisingly, the electron-donor or -acceptor properties of ring substituents in ferrocenes and other metallocenes have been repeatedly evaluated with electrochemical techniques. Measurements have been obtained using polarography,150 cyclic voltammetry (CV),151 chronopotentiometry,152 photoelectron spectroscopy, 53 and Fourier transform ion cyclotron resonance mass spectrometry.154 Extensive compilations of such data are available.155 156 Historically, variations of oxidation potentials have been discussed almost solely in terms of the... 

The next important quantity is the interaction energy, which may be obtained experimentally through the measurement of association or complexation constants K (for instance, via Fourier-Transform Ion Cyclotron Resonance mass spectrometry or Nuclear Magnetic Resonance (NMR) spectroscopy see also the other chapters in this volume) that are related to the total free enthalpy change AG of the host-guest complexation through... 

In this study, gaseous organic cations were generated by the technique of ion cyclotron resonance (ICR) spectroscopy, which is a form of mass spectroscopy... 

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