ISSN:
0030-493X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The 248 nm laser desorption Fourier transform ion cyclotron resonance positive- and negative-ion mass spectra are presented for two novel porphyrin-spacer-quinone bichromophoric systems in which the spacer consists of a polynorbornyl-type hydrocarbon and also for a model tetraphenylporphyrin compound. The compounds are 1,2,3,4-tetrahydro-1.4-methano-7,10,13,16-tetraphenylbenzo [g] quinoxalino [2,3-b] porphyrin, 5,20-dihydro-5,20-methano-l,4-dimethoxy-8,11,14,17-tetrapherylnaphtho [2,3-g]quinoxalino[2,3-b] porphyrin and 5,10,15,20-tetraphenyl-porphyrin. The two-step laser desorption multiphoton ionization mass spectra recorded at laser powers 〈 2 MW cm-2 produce only the parent ions M+· and M-·. At increased laser powers of up to 5 MW cm-2 the [M + H]+ and [M — H]- ions are observed to increase significantly in relative abundance. At laser powers 〉8 MW cm-2 the porphyrins show extensive photodissociation and rearrangement and, in one case, the production of an extensive distribution of carbon cluster fragment ions including the fullerene [C60]+·.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/oms.1210271013
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