Arsenic mass spectra

The phosphorus chemical shift observed for the arsenic derivative 5 P = 315 is in accordance with the monomeric structure (39). This, however, is not the case for that observed for the antimony derivative, P = 44.5. The mass spectrum of the latter confirms its dimeric structure (37). 

Alkylphosphines have been studied (99, 231), as have cyclopolyphos-phines (120). The reaction products of phosphorus with various olefins were investigated using mass spectral methods (108), and a large number of phospholines have been reported (181, 237). The mass spectrum of the trimer of tetramethylphosphinoborine showed that B—P, C—B, and C—P bonds were broken first, and with the pentamer of the dimethyl compound, B—H, B—P, and C—P bonds were broken (101, 232). The spectra of thiophosphorustri-A -methylimide and its arsenic analog were reported by Holmes and Forstner (130). Ionization potentials have been recorded for many perfluoroalkylarsines and some of the related alkyl compounds (79). 

Fig. 3. Mass spectrum of the impurity, OAs2(C6F4)2, occurring in As2(C6F4)3 made by heating arsenic (containing traces of As203) with 1,2-diiodotetrafluorobenzene.

As an example of RBS applied to a polymer system, figure 3.22 shows the spectrum obtained from a sample of the conjugated polymer poly(phenylene, vinylene) after exposure to arsenic pentafluoride vapour (Masse et al. 1990). This dopant diffuses into the polymer and reacts with it to form an electrically conducting complex and RBS is well suited to following the kinetics of the doping process by providing concentration-depth profiles of the elemental components of the dopant as a function of time. The peaks in the spectrum... 

Figure 3.22. The RBS spectrum of a poly(phenylene vinylene) sample after it had been exposed to arsenic pentafluoride vapour for 5 days. After Masse et al. (1990).

Vanhaecke, R, Boonen, S., Moens, L., and Dams, R. (1995) Solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry for the determination of arsenic in standard reference materials of plant-origin. J. Anal. At. Spectrum., 10,81-7. 

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