Ion beam mass spectrometry

Figure 4.7. Boron scanned ion beam mass spectrometry (SIMS) image of a B-doped diamond specimen. The image is 430 pm in width, and the variation of B intensity from one grain to another is approximately a factor of 8. (Reproduced by permission of Professor J. W. Steeds.)...

A parallel investigation on the binding of alkali metal cations to nucleobases, employing guided ion beam mass spectrometry, has recently been reported by Rodgers and Armentrout . ... 

Gibbs free energies of formation, 33 127 GIBMS, see Guided-ion-beam mass spectrometry... 

Guanosine nucleotide, redox pathways, 43 129 Guided-ion-beam mass spectrometry, metal-0X0 systems, 44 323 Gutmann donor number, 34 174 Gypsum... 

Guided-ion-beam mass spectrometry (GIBMS) was used to study the reaction of CoO+ with CH4 and with D2 (.223). The exothermic reaction with methane, Eq. (4), was found to have an activation barrier of... 

Hydridophosphino complexes have been described previously (Section 33.2.4). The bond dissociation energy of 209 kJ mol-1 has been measured5 by ion beam mass spectrometry using the reaction in equation (1). The bond energies between V+ and other atoms were compared with the corresponding carbon bonds the energy of the bond to vanadium is about one half that of the corresponding carbon bond. 

Armentrout PB (1992) Thermochemical measurements by guided ion beam mass spectrometry. In Adams N, Babcock LM (eds) Advances in gas phase ion chemistry, vol 1. JAI Press, Greenwich, CT, p 83... 

The reaction of alkanes with simple or complex ions in the gas phase can be conveniently studied by ion beam mass spectrometry or by ion cyclotron resonance. Ridge et al. found that naked Fe ions could not only break C-H but also C-C bonds of n-butane and isobutane (Scheme 6.33). 

Chen and Armentrout45 used guided ion beam mass spectrometry on the ion (C2H4Ag)+ and, while they could show it is the aforementioned Ag-(C2H4)+(g), they could only derive a lower limit of (22.2 6.8) k.l mol 1 for equation 20 at 0 K. How can the two numerical values of ArH° (20) be reconciled the Guo/Castleman one is seemingly too high and/or the Chen/Armentrout one is too low. 

GIBMS = guided ion beam mass spectrometry HPMS = high pressure mass spectrometry ICR = ion cyclotron resonance mass spectrometry KC-MS = Knudsen cell-mass spectrometry. cData at 298 K. 

Ion chemistry experiments can also provide information about the thermochemistry of neutral molecules50. Guided ion-beam mass spectrometry experiments45 allow us to... 

Guided ion beam mass spectrometry studies give values for Z) (Cr-Me) = 37.9 2.0 kcal moH and )o(Cr+-Me) = 30.3+1.7 kcal mol. 2 Results also indicate that excited quartet states of Cr+ react very differently with alkanes than ground state Cr+( S). Calculations suggest that the metallacycles formed by insertion of transiticm metal atoms including Cr, Mo, and W into the C—O bond of ethene oxide are more stable than [metal + epoxide]. ... 

Elkind et al. s (1989) experiment on the reactivities of La, Sc, Y and Lu with H2 using guided ion beam mass spectrometry revealed that La reacted with H2 primarily through an insertion mechanism. Their surface ionization (SI) beam of La was found to be 69% (d ), 12% (ds) and 15% (ds). Since the La ( F d ) forms only loose... 

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