Gas-phase ion-molecule charge-exchange reactions of iron(1+) with iron pentacarbonyl: observation of higher lying metastable electronic states

Abstract

respective polynuclear aromatic hydrocarbon counterparts. This phenomenon remains to be further investigated. Finally, the sensitive nature of chiral recognition by CDx's may be used to provide further insight into the binding or interaction of third components in CDx/heterocyclic systems. Warner, I. M. J. Phys. Chem. 1991, 95, 4897. Phys. Chem. 1990, 94, 5020. 1981. (1) Schuette, J. M.; Ndou, T. T.; Mufioz de la Pefia, A.; Greene, K. L.; (2) Bergmark, W. R.; Davis, A.; York, C.; Macintosh, A.; Jones, G. 11. J. (3) Lin, S.-F. Ph.D. Dissertation, University of Wisconsin in Madison, (4) Matsui, Y.; Mochida, K. Bull. Chem. SOC. Jpn. 1979, 52, 2808. (5) Szejtli, J. Cyclodextrins and Their Inclusion Complexes; Akademiai (6) Schuette, J. M.; Ndou, T. T.; Warner, I. M. J. Am. Chem. SOC., in (7) Mufioz de la Pefia, A.; Ndou, T. T.; Zung, J. B.; Greene, K. L.; Live, (8) Zung, J. B.; Ndou, T. T.; Mufioz de la Pefia, A.; Warner, I. M. J. Phys. (9) Ishizuka, Y.; Nagawa, Y.; Nakanishi, H.; Akira, K. J. Inclusion (10) Kobayashi, N.; Opallo, M. J. Chem. SOC. Commun. 1990, 477. (11) Ata, M.; Kubozono, Y.; Suzuki, Y.; Aoyagi, M.; Gondo, Y. Bull. Kiado: Budapest, 1982. press. D. H.; Warner, I. M. J . Am. Chem. SOC. 1991, 113, 1572. Chem. 1991, 95, 6701.Charge-exchange ion-molecule reactions of Fe' with Fe(C0)5 formed by 20-70-eV electron impact of Fe(C0)5 are reported. The charge-exchange reaction chemistry data indicate that electronic states with energies up to about 4.0 eV are produced and that 40% of the excited-state ions are in the first excited state 4F(3d7) and the remaining 60% are in the 4D(4s13d6) to *G(4s'3d6) or higher energy states. Of the Fe+ produced by 50-70-eV ionizing energy 65% are formed as excited states and about 35% as ground state 6D(4s'3d6). The results from charge-exchange ion-molecule reactions are compared to the excited states determined by other methods.

Iron cation catalyzed reduction of N2O by CO: gas-phase temperature dependent kinetics

“…For an electron energy of about 50 eV (typical of some of the experiments presented here), it has been shown that one may expect about 40% of the ground electronic state, 6 D, with the remaining contributions primarily from the excited 4 F and 4 D states. [29][30][31] Additionally, it has been shown that the 4 D state may not be efficiently quenched by helium under experimental conditions similar to ours. 22,29 With the Fe + + N 2 O rate being slow, we should observe curvature in the decay plots if two states are present and reacted differently.…”

Collisional relaxation of metastable electronic states of Fe+

“…L Fe,(CO): + CO (8) Reactions l-5 are nondissociative and dissociative charge-transfer reactions and reactions 6-8 are condensation or clustering reactions [201. The charge-transfer products (reactions l-5) and the ionic cluster fragments Fe,(CO): and Fe,(CQ): are formed by reactions of electronically excited metastable states of (Fe+)*, whereas the Fe,(CO),+ ionic cluster fragment is J Am Sot Mass Spectrom 1995,6,543-553 formed exclusively by reactions of (Fe+)".…”

“…An important consideration for determination of the rate constants for the collisional relaxation of (Fe+)* is to differentiate between the ionic product channels and collisional relaxation reactions. ColIisional relaxation of (Fe+)* by He, Ar, and Kr is not affected by highly endoergic charge-exchange reactions (ionization energies: He = 24.6 eV [27], Ar = 15.76'eV [8], and Kr = 14.00 eV [28]). Therefore, in the reaction of (Fe+)* with He, Ar, and Kr the rate of disappearance of Fe(CO)l is a direct measure of collisional relaxation.…”

Successive reactions of iron carbonyl cations with dimethyl ether: direct cleavage versus rearrangement

“…The product Fe(DME) 2 + is also obtained from Fe(CO)(DME) + through reaction (8), so that Fe(DME) 2 + is the major terminal ion. Similarly to its methanol analogue, Fe(CO)(DME) 2 + does not undergo further CO substitution, but is slowly transformed through reactions (19) and (20), described under the Fe(CO) 4 + /DME system where they are more important.…”