Fourier Transform-Ion Cyclotron Resonance-Mass Spectrometer as a New Tool for Organic Chemists

Abstract

Currently, mass spectral determination of molecular weights and elemental compositions of synthetic products is a common practice. It is aided by truly impressive developments in methods and instrumentation enabling to characterize great variety of compounds including even those of a relatively high molecular weight. Confidence in such measurements, however, depends upon selecting a suitable ionization method, unambiguous identification of a molecular-type ion, and the adequate precision of mass determinations. This review addresses major aspects of the ion formation and analysis with special attention given to the ion-cyclotron resonance. This powerful technique, different in its principle from most other methods of ion analysis, offers a superb combination of ion manipulation and measurement parameters and full compatibility with an array of ionization methods.Key words: mass spectrometry, ultra-high resolution mass spectrometry, ion-cyclotron-resonance, soft ionization, stable isotopes, molecular weight determination. Trapping ions in the ICR-cell 2.3.3.Detection of the trapped ions 2.3.4.Getting ions into the ICR Cell 2.4.Tandem mass spectrometry 2.4.1.Tandem mass spectrometry with magnetic-sectors and quadrupoles 2.4.2.Tandem-MS with FT-ICR-MS 3.Ion formation 3.1. Overview 3.2.Electron impact ionization 3.3.Chemical ionization 3.4.Fast atom bombardment 3.5.Matrix assisted laser desorption/ionization 3.6. Cationization 3.7.Electrospray ionization 4.Mass spectrometry and molecular weight determination 4.1.Stable isotopes and molecular ions 4.2.Isotopic depletion and substitution 4.3.High or ultra-high resolution? 4.4.Mass measurement accuracy 4.5.Can molecular weight be unequivocally determined by mass spectrometry? IntroductionMass spectrometry (MS) is the technique that renders mass-to-charge ratios (m/z) and relative intensities of ions formed (with exceptions), separated, and detected in the high vacuum. The remarkable analytical potentials of MS have been immediately recognized by its inventor J. J. Thomson and, in years immediately following the First World War, the detection and precise characterization of isotopes of almost all elements have been achieved employing the very first mass spectrographs and spectrometers. 1 With some delay, however, these seminal discoveries have been followed by a systematic effort to analyze organic compounds. Ever since, thanks to a steady progress in techniques and instrumentation, MS continues to serve in a variety of inorganic and organic applications. Moreover, by gaining truly astonishing capabilities in terms of ionization, mass range, sensitivity, and accuracy, MS methods cover classes of compounds that originally have been considered as entirely unsuitable for such an analysis.2 Still, as exemplified by the recent synthesis of two diterpenoids, 3 synthetic work can be carried out with the complete omission of MS. As a rule, however, MS data are used to confirm MW and to replace elemental analyses of the final reaction products. Only seldom, synthetic p...

Study by ESI‐FTICRMS and ESI‐FTICRMSn of zinc and cadmium thiophenolate complexes used as precursors for the synthesis of II–VI nanosemiconductors

“…[7 -10] Depending on the ionization technique and the mass spectrometer system used, atomic, molecular, and structural information are available. [11] Consequently, MS appears well suited to investigate NCs and their precursors as well as to follow up the different steps of II-VI nanomaterial synthesis. According to the used ionization techniques, different information may be obtained.…”

Novel Chemical Tagging Method for Combinatorial Synthesis Utilizing Suzuki Chemistry and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

“…Each washing cycle consisted of bubbling with nitrogen for 2 min and filtering with a water aspirator. Washes were typically with the following sequence: CH 2 Cl 2 ( (12). To lowmesh chloromethyl resin (1.8 mequiv, 400 mg, 0.72 mmol sites) swollen in DMA (4 mL each) were added nonylphenol (24 mg in DMA (1 mL), 0.15 equiv), iodophenol (40 mg, 0.25 equiv), and sodium methoxide (16 mg, 0.4 equiv), and this suspension shaken and washed as described above to give 12 as a white powder (432 mg, implies approximately 15% iodophenol loading and 9% tag loading).…”

“…Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) has emerged as a powerful tool for the accurate mass analysis of compounds with high sensitivity. , This is an ideal instrument for the detection of chemical tags owing to the potential for accurate mass analysis of mixtures of compounds, thus allowing for a measure of certainty in the decoding of a binary-type tagging system from a mass spectrum. Further, the levels of detection are more than adequate for detection of tags from a low percentage of sites from a single bead in a combinatorial synthesis.…”

π Complexes with Annellated Cyclobutene Rings: Bicyclo[3.2.0]heptadienyl Anion and Benzocyclobutene as Ligands for Transition Metals

“…93 FT-ICR MS stands for Fourier transform ion cyclotron resonance mass spectrometry. [94][95][96] 74 undergoes nucleophilic addition reactions with formation of exo adducts with high diastereoselectivity at -78°C. Double nucleophilic additions are possible as well, leading to cis diadducts.…”