J. Phys. Chem. 1992,96,9111-9113
bonding, the ionization potential differences, and the relative density of electronic states in the wavelength region of interest. Both processes are expected for all metal-benzene ion complexes and probably for all metal-molecule complexes in general, depending on the excitation energy. The energy threshold for dissociative charge transfer provides a new route for the determination of metal ion-molecular dissociation energies. Dissociation energies are determined for magnesium, iron, and silver ion complexes with benzene. The consensus of both theory and several experiments is that the ironbenzene system is quite strongly bound, while silver and magnesium systems have similar much weaker bonding. The present data base for these and other related complexes is quite limited, and the method described here promises to provide a general source of information for a variety of metal-ligand combinations. Acknowledgment. We appreciate helpful discussions with Charlie Bauschlicher, Ben Freiser, and Peter Armentrout. This research was supported by the National Science Foundation through Grant CHEM-9008246.
References and Notes (1) Winstein, S.;Lucas, H. J. J . Am. Chem. SOC.1938, 60, 836. (2) Andrews, L. J. Chem. Rev. 1954, 54, 713. (3) Smith, H. G.;Rundle, R. E. J . Am. Chem. SOC.1958, 80, 5075. (4) Tranham, J. G.;Olechowski, J. R. J . Am. Chem. SOC.1959,81,571. ( 5 ) Mulliken, R. S.J . Am. Chem. Soc. 1952, 64, 811. (6) (a) Castleman, A. W.; Holland, P. M.;Lindsay, D. M.; Peterson, K. I. J . Am. Chem. Soc. 1978,100,6039. (b) Castleman, A. W. Chem. Phys. Leu. 1978, 53. 560. (c) Holland. P. W.. Castleman. A. W. J. Chem. Phvs. 1982, 76,4195. (d) Gkin, K. L.i Guo, B. C.; Kees&, R. G.; Castleman,'A. W. J. Phys. Chem. 1989,93, 6805. (7) Magnera, T. F.; David, D. E.; Michl, J. J. Am. Chem. SOC.1989,111, 4100. (8) Marinelli, P. J.; Squires, P. R. J . Am. Chem. SOC.1989, 1 1 1 , 4101. (9) (a) Shen, M. H.; Farrar, J. M. J . Phys. Chem. 1989, 93, 4386. (b) Shen, M. H.; Farrar, J. M. J . Chem. Phys. 1991, 94, 3322. (10) (a) Lessen, D. E.; Asher, R. L.; Brucat, P. J. J . Chem. Phys. 1990, 93,6102. (b) Lessen, D. E.; Asher, R. L.; Brucat, P. J. J. Chem. Phys. 1991, 95, 1414.
9111
(1 1) Bouchard, F.; Hepburn, J. W.; McMahon, T. B. J . Am. Chem. Soc. 1989, 1 1 1,8934. (12) El-Shall, M. S.;Schriver, K. E.; Whetten, R. L.; Mautner, M. J. Phvs. Chem. 1989. 93. 7969. 113) (a) Hettich, R.'L.; Freiser, B. S . J . Am. Chem. Soc. 1987,109,3543. (b) Freiser, B. S.Chemrracrs: Anal. Phys. Chem. 1989,1,65. (c) Lech, L. M. Ph.D. Thesis, Purdue University, 1988. (d) Hettich, R. L.; Jackson, T. C.; Stanko, E. M.; Freiser, B. S.J . Am. Chem. Soc. 1986, 108, 5086. (e) Freiser, B. S. Private communication. (14) Gantefor, G.;Siekmann, H. R.; Lutz, H. 0.; Meiwcs-Broer, K. H. Chem. Phys. Lerr. 1990, 165, 293. (15) Selegue, T. J.; Moe, N.; Draves, J. A.; Lisy, J. M. J. Chem. Phys. 1992, 96, 7268. (16) Armentrout. P. B. Private communication. (17) (a) Willey, K. F.; Cheng, P. Y.; Pearce, K. D.; Duncan, M. A. J . Phys. Chem. 1990,94,4169. (b) Willey, K. F.; Cheng, P. Y.;Bishop, M. B.; Duncan, M. A. J. Am. Chem. Soc. 1991, 113. 4721. (18) Dunkr, R. C. In Gas Phase Inorganic Chemistry; Russell, D. H., Ed.; Plenum Press: New York. 1989. (19) (a) Willey. K. F.; Yeh, C. S.;Robbins, D. L.; Duncan, M. A. Chem. Phys. Lerr. 1992, 192, 179. (b) Yeh, C. S.;Willey, K. F.; Robbins, D. L.; Pilgrim, J. S.;Duncan, M. A. Chem. Phys. Lerr. 1992, 196. 233. (20) (a) Bauschlicher, C. W.; Partridge, H.;Langhoff, S. R. J. Chem. Phys. 1989,91,4733. (b) Rosi, M.; Bauschlicher,C. W. J. Chem. Phys. 1989, 90, 1264. (21) (a) Bauschlicher, C. W.; Partridge, H. J. Phys. Chem. 1991,95,3946. (b) Bauschlicher, C. W.; Partridge, H. Chem. Phys. Lea. 1991, 181, 129. (c) Sodupe, M.; Bauschlicher, C. W.; Partridge, H. Chem. Phys. Lerr. 1992,192. 185. (22) (a) Bauschlicher, C. W.; Partridge, H.; Langhoff, S . R. J . Phys. Chem. 1992,96,3273. (b) Bauschlicher, C. W.; Partridge, H. Chem. Phys. Leu. 1991, 181, 129. (23) (a) LaiHing, K.; Cheng, P. Y.; Taylor, T. G.;Willey, K. F.; Ptschke, M.; Duncan, M. A. Anal. Chem. 1989,61,1458. (b) Comett, D. S.;Pcschke, M.; LaiHing, K.; Cheng, P. Y.; Willey, K. F.; Duncan, M. A. Reu. Sci. Instrum. 1992, 63, 2177. (24) Beyer, R. A.; Vanderhoff, J. A. J. Chem. Phys. 1976, 65, 2313. (25) (a) Jarrold, M. F.; Misev, L.; Bowers, M. T. J. Chenr. Phys. 1984, 81,4369. (b) Kim, H.-Y.; Kuo,C.-H.; Bowers, M.T. J . Chem. Phys. 1987, 87. 2661. (26) Bieske, E. J.; Soliva, A. M.; Friedman, A.; Maier, J. P. J. Chem. Phys. 1992, 96, 7535. (27) McMahon, T. Private communication via B. Freiser. (28) The typical upper limit on bond energies which can be measured in a high-pressure mass spectrometer experiment is 35 kcal/mol. I~
Li+ Polarizability Due to Collective Motion of Li+ Ions in Dilithium Salts of 2,6-Bis( (diethyiamino)methyl)phenolate Dl-N-oxides as a Function of the Electron Density at the 0 Atom of the Phenolate Group Bogumil Brzezinski, Hanna Maciejewska, Faculty of Chemistry, A . Mickiewicz University, Grunwaldzka 6, PL-60780 Poznafi, Poland
and Georg Zundel* Physikalisch- Chemisches Institut, Universitiit Munchen, Theresienstrasse 41, 0-8000Mirnchen 2, FRG (Received: January 7, 1992)
Six dilithium aurates of 2,6-bis((diethylamino)methyl)-3,4-R-phenoldi-N-oxides were studied in the far-infrared (far-IR) region as a function of the electron density at the 0 atom of the phenolate group. Continua in the FIR region indicate
