Laser, induced dissociation

Leforestier C and Wyatt R E 1983 Optical potential for laser induced dissociation J. Chem. Phys. 78 2334... 

Since enthalpy changes can be obtained directly from measurement of heat absorption at constant pressure, even small values of AH for chemical and biochemical reactions can be measured using a micro-calorimeter.1112 Using the technique of pulsed acoustic calorimetry, changes during biochemical processes can be followed on a timescale of fractions of a millisecond. An example is the laser-induced dissociation of a carbon monoxide-myoglobin complex.13... 

Rothe, E.W., Krause, U. and Duren, R. (1980). Observation of polarization of atomic fluorescence excited by laser-induced dissociation of Na2, Chem. Phys. Lett., 72, 100-103. 

Similar laser-induced dissociation of "colored vapors and vapor complexes has been recently reported for a number of metal-halide systems ( 2, 50). 

Photodissociation yields of UF have been measured as a function of incidient light intensity in the presence of various additives,225 nd multiphoton ionisation of UF as a probe of laser-induced dissociation of UF, has been investigated using an... 

A natural extension of the method consists of using it to monitor the nascent vibrational and rotational energy distribution in the products of a chemical reaction. The use of nanosecond laser sources and low enough substrate pressure can make the method most useful in the case of laser-induced dissociation (single or multiphoton). This application has recently been demonstrated for the photodissociation of CFjNO. ... 

Once the exact mass is determined for the precursor ion, the instrument is switched to tandem MS mode (TOF/TOF mode) and fragment ions are generated using laser-induced dissociation (LID) and/or high energy collision-induced dissociation (CID) (13) (see Note 12). 

Macht, M., Asperger, A., and Deininger, S. O. (2004) Comparison of laser-induced dissociation and high-energy collision-induced dissociation using matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOE/TOF) for peptide and protein identification. Rapid Commun. Mass Spectrom. 18, 2093-2105. 

H. Abou-Rachid, T.T. Nguyen-Dang, O. Atabek, Dynamical quenching of laser-induced dissociations ofheteronuclear diatomic molecules in intense infrared fields, J. Chem. Phys. 110 (1999) 4737. 

Nitrogen isotopes have been separated by gas chromatography. The separation of from was effected on a graphon column at 77°K [51 ], a partial separation having been previously obtained on glass capillary columns [52]. A laser-induced dissociation reaction of s-tetrazine has been reported to show separation of nitrogen-14 and -15, and of carbon-12 and -13 [53]. 

Liquid chromatography/mass spectrometry Laser-induced dissociation Liquid injection field desorption ionization Linear-acceleration high-pressure collision cell Linear quadntpole ion trap... 

The combination of ion traps with lasers has opened up a wide range of innovative experiments. In addition to the information obtained from detecting reemitted or stimulated photons, there are many laser based schemes for probing or manipulating a trapped ensemble including optical pumping, laser induced dissociation, or light stimulated chemical reactions. Lasers are utilized for state specific creation of ions in the trap. 

Lewandrowski, U. Resemann, A. Sickmann, A. Laser-induced dissociation/high-energy collision-induced dissociation fragmentation using MALDI-TOF/TOF-MS instrumentation for the analysis of neutral and acidic oligosaccharides. Anal. Chem. 2005, 77, 3274-3283. 

Pulsed electronic transition chemical laser operation appears to be possible in a much wider class of reaction systems than those defined by the foregoing considerations. Reaction initiation in premixed reagents by pulsed techniques can provide population inversions on time scales short compared with fluid mixing times and relaxation times for lower laser states. Such techniques include photolysis, laser-induced dissociation, electrical discharge production of atoms or metastables, and shock-induced dissociation and pyrolysis. Such lasers are subject to the pumping rate condition of Figure 3.21 which is much less restrictive than the condition for diffusive mixing... 

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