This review offers an introduction to the principles and generic applications of FT-ICR mass spectrometry, directed to readers with no prior experience with the technique. We are able to explain the fundamental FT-ICR phenomena from a simplified theoretical treatment of ion behavior in idealized magnetic and electric fields. The effects of trapping voltage, trap size and shape, and other nonidealities are manifested mainly as perturbations that preserve the idealized ion behavior modified by appropriate numerical correction factors. Topics include: effect of ion mass, charge, magnetic field, and trapping voltage on ion cyclotron frequency; excitation and detection of ICR signals; mass calibration; mass resolving power and mass accuracy; upper mass limit(s); dynamic range; detection limit, strategies for mass and energy selection for MSn; ion axialization, cooling, and remeasurement; and means for guiding externally formed ions into the ion trap. The relation of FT-ICR MS to other types of Fourier transform spectroscopy and to the Paul (quadrupole) ion trap is described. The article concludes with selected applications, an appendix listing accurate fundamental constants needed for ultrahigh-precision analysis, and an annotated list of selected reviews and primary source publications that describe in further detail various FT-ICR MS techniques and applications. © 1998 John Wiley & Sons, Inc., Mass Spec Rev 17, 1–35, 1998

Fourier transform ion cyclotron resonance mass spectrometry: A primer

Catalytic growth of single-walled manotubes by laser vaporization

Main-group analogues to fullerene-C60 have been predicted theoretically many times. Now, B40− has been observed using photoelectron spectroscopy and, with its neutral analogue, B40, confirmed computationally. In contrast to fullerene-C60, the all-boron fullerene (or borospherene) features triangles, hexagons and heptagons, bonded uniformly by delocalized σ and π bonds over the cage surface.

http://casey.brown.edu/chemistry/research/LSWang/publications/399.pdf

Observation of an all-boron fullerene.

Encapsulating atoms or molecules inside fullerene cages could give rise to a myriad of novel molecules and materials. The existence of such species is now strongly supported by a growing body of experimental evidence. Fullerene& ndash;metal complexes generally thought to be endohedral are being produced and purified in milligram quantities, and their structure and properties are beginning to be explored

Atoms in carbon cages: the structure and properties of endohedral fullerenes

Production processes for carbon nanotubes often produce mixtures of solid morphologies that are mechanically entangled or that self‐associate into aggregates. Entangled or aggregated nanoparticles often need to be dispersed into fluid suspensions in order to develop materials that have unique mechanical characteristics or transport properties. This paper reviews the effects of milling, ultrasonication, high shear flow, elongational flow, functionalization, and surfactant and dispersant systems on morphology of carbon nanotubes and their interactions in the fluid phase. Multiwalled carbon nanotubes (MWNTs) have been used as an example model system for experimental work because they have been available in engineering‐scale quantities and can be dispersed reproducibly in a variety of solvents and polymers. Their size scales, ∼30–50 nm in average diameter and ∼5–50 microns in length, permit MWNT dispersions to be investigated using transmission electron microscopy, scanning electron microscopy, and i...

Dispersion of Carbon Nanotubes in Liquids

XPS probes of carbon-caged metals

Reaction rates and saturation values were determined for H2 dissociative chemisorption on positive niobium cluster ions in an FT‐ICR apparatus. Clusters with 8,10,12, and 16 atoms were found to be particularly unreactive, in remarkable agreement with the reactivity patterns observed previously for neutral niobium clusters. Saturation coverage for most clusters was found to occur near a hydrogen/niobium ratio of 1.3, although some clusters (8–12,16, and 19) reached effectively inert compositions at considerably lower coverages. Several examples were found of clusters having two isomeric forms with different reactivities. One form of Nb+19 was found to readily react with H2, whereas a second form representing one‐third of the original sample of 19 atom clusters was completely inert to H2 chemisorption under the same FT‐ICR conditions. The geometrical shape of these niobium clusters must therefore have a critical effect on reactivity.

Fourier transform ion cyclotron resonance studies of H2 chemisorption on niobium cluster cations

FT‐ICR techniques were used to probe the surface chemistry of isolated silicon cluster ions in the 7–65 atom size range. Dissociative chemisorption reactions with NH3 were observed to proceed with rates which varied widely with cluster size. One particular cluster, Si+39, was found to be remarkably inert. Clusters with 20, 25, 33, and 45 atoms were found to be unreactive as well, while those with 18, 23, 30, 36, 43, or 46 atoms were quite reactive. Similarly oscillating reaction patterns were observed with CH3OH, whereas highly reactive free radical scavengers such as O2 and NO showed little selectivity. These results suggest the silicon clusters in this size range have well‐defined structures which vary in ability to catalyze dissociative chemisorption at the surface.

FT‐ICR probes of silicon cluster chemistry: The special behavior of Si+39

The electronic structure of Ca@C60

Silicon clusters in the size range from 5 to 66 atoms were generated by laser vaporization in a supersonic nozzle and injected into the ion trap of a specially‐designed Fourier transform ion cyclotron resonance apparatus. On the positively charged clusters ammonia chemisorption reaction rates were found to vary by over three orders of magnitude as a function of cluster size, with clusters of 21, 25, 33, 39, and 45 atoms being particularly unreactive, and cluster 43 being the most reactive. For the negative cluster ions, 43 was the only cluster found to react substantially. Although the reaction behavior of many clusters clearly indicated that several structural isomers were present with different reaction rates, the strikingly low net reactivity of such clusters as 39 and 45 provides evidence that they have effectively crystallized into a single specially stable form.

J. M. Alford

Papers

XPS probes of carbon-caged metals

Fourier transform ion cyclotron resonance studies of H2 chemisorption on niobium cluster cations

FT‐ICR probes of silicon cluster chemistry: The special behavior of Si+39

The electronic structure of Ca@C60

Ammonia chemisorption studies on silicon cluster ions