Multiphoton dissociation

Wight C A and Armentrout P B 1993 Laser photoionization probes of ligand-binding effects in multiphoton dissociation of gas-phase transition-metal complexes ACS Symposium Series 530 61-74... 

Figure 9.30 Vibrational energy level scheme for multiphoton dissociation...

Figure 9.31 Detection of products of multiphoton dissociation by laser-induced fluorescence...

The phenomenon of multiphoton dissociation finds a possible application in the separation of isotopes. For this purpose it is not only the high power of the laser that is important but the fact that it is highly monochromatic. This latter property makes it possible, in favourable circumstances, for the laser radiation to be absorbed selectively by a single isotopic molecular species. This species is then selectively dissociated resulting in isotopic enrichment both in the dissociation products and in the undissociated material. 

Figure 9.32 Isotopic enrichment of SFg by multiphoton dissociation following irradiation in the vibrational band of SFg. The absorption spectrum is shown (a) before and (b) after irradiation. (Reproduced, with permission, from Letokhov, V S., Nature, Land., Ill, 605, 1979 Copyright 1979 Macmillan Journals Limited)...

CCI2F2 (dichlorodifluoromethane) multiphoton dissociation, 374 CFl4 (methane)... 

Auger electron spectmm, 320 multiphoton dissociation, 376 principal axes, 105 symmetry elements, 76, 85 "SFg... 

Fig. 20. The photofragment TOF mass spectrometry from the dissociation of C6Hb13CH3 in two different mass regions. The fragment of m/e = 76 results from multiphoton dissociation.

The chemiluminescent response of hydrocarbons reacting with an excess of fluorine atoms produced by multiphoton dissociation of SF6 is linear below 50 parts per million (ppmv) [61]. 

Woodin, R.L. Bomse, D.S. Beauchamp, J.L. Multiphoton Dissociation of Molecules With Low Power Continuous Wave Infrared Laser Radiation. J. Am. Chem. Soc. 1978,100, 3248-3250. 

The activation step can alternatively be performed without gas by means of infrared multiphoton dissociation (IRMPD) or electron capture dissociation (BCD) (Chap. 2.12.2). Both IRMPD and BCD, solely require storage of the ions during their excitation by photons or electrons, respectively. It is one of the most charming properties of FT-ICR-MS/MS that even the accurate mass of the fragment ions can be determined. [216,217]... 

Hashimoto, Y. Hasegawa, H. Yoshi-nari, K. Collision-Activated Infrared Multiphoton Dissociation in a Quadrapole Ion Trap Mass Spectrometer. Anal. Chem. 2003, 75,420-425. 

Gauthier, J.W. Trautman, T.R. Jacobson, D.B. Sustained Off-Resonance Irradiation for Collision-Activated Dissociation Involving FT-ICR-MS. CID Technique That Emulates Infrared Multiphoton Dissociation. Anal. Chim. Acta 1991,246,211-225. 

Hofstadler, S.A. Griffey, R.H. Pasa-Tolic, R. Smith, R.D. The Use of a Stable Internal Mass Standard for Accurate Mass Measurements of Oligonucleotide Fragment Ions Using ESI Fourier Transform Ion Cyclotron Resonance-MS With Infrared Multiphoton Dissociation. Rapid Commun. Mass Spectrom. 1998,12, 1400-1404. 

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