STRUCTURAL-PROPERTIES AND PHYSICAL-PROPERTIES OF DELOCALIZED MIXED-VALENT [CP-ASTERISK-M(PENTALENE)M'CP-ASTERISK](N+) AND [CP-ASTERISK-M(INDACENE)M'CP-ASTERISK](N+) (M, M'=FE, CO, NI, N=0, 1, 2) COMPLEXES

被引:162
作者
MANRIQUEZ, JM
WARD, MD
REIFF, WM
CALABRESE, JC
JONES, NL
CARROLL, PJ
BUNEL, EE
MILLER, JS
机构
[1] DUPONT CO INC,EXPTL STN,SCI & ENGN LABS,WILMINGTON,DE 19880
[2] NORTHEASTERN UNIV,DEPT CHEM,BOSTON,MA 02115
关键词
D O I
10.1021/ja00128a004
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The structural characterization and physical properties of [Cp*M(pentalene)M'Cp*](n+) (Cp* = pentamethylcyclopentadiene; M, M' = Fe, Fe (1a); Co, Co (1b); Ni,Ni (1c); Ru, Ru (1d); Fe, Ru (1e); Fe; Co (if); n = 0, 1,2) and [Cp*M(s-indacene)M'Cp*](n+) (s = symmetric) and [Cp*M(as-indacene)M'Cp*](n+) (M, M' = Fe, Fe (2a, 3a); Co, Co (2b, 3b); Ni, Ni (2c, 3c); n = 0, 1, 2) (as = asymmetric) are reported. The local molecular structure of the organometallic complex does not change significantly with oxidation state; in all cases the Cp*M moieties reside on opposite faces of the fused mu-bridging ring systems, reflecting the dominance of steric effects. These complexes generally exhibit behavior consistent with significant electronic interactions between metal centers, including large electrochemical potential separations between successive one-electron redox events, and for the mixed valent (n = 1+) complexes, intervalent charge transfer absorption bands. The magnetic susceptibility data are consistent with intramolecular ferromagnetic coupling of spins for 1a(2+) and 2c(2+) and antiferromagnetic coupling of spins for 1c, 1c(2+), 1b, 2b, 1c(+), 2c(+), and 3c(+). In general, the paramagnetic complexes exhibit Curie-Weiss behavior, except for 2c and 3c, which possess singlet ground states and high spin excited states that are 0.036 and 0.056 eV (290 and 524 cm(-1)) above the ground state, respectively. Mixed-valent 1a(+) and 2a(+) are fully detrapped on the Mossbauer time scale (i.e., electron transfer rates, greater than or equal to 10(7) s(-1)) above 1.5 K, consistent with a negligible energy barrier to intramolecular electron transfer or complete delocalization. The EPR spectra of 1a(+), 2a(+), and 1e(+) exhibit significantly reduced g-factor ansiotropies and more intense spectral features at ambient temperature:compared to [FeCp*(2)](.+), implying intramolecular electron transfer rates greater than or equal to 10(10) s(-1).
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页码:6182 / 6193
页数:12
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共 22 条
  • [1] Hendrickson D.N., Kramer J.A., Inorg. Chem., 19, (1980)
  • [2] Creutz C., Taube H., J. Am. Chem. Soc., 91, (1969)
  • [3] Webb R.J., Geib S.J., Staley D.L., Rheingold A.L., Hendrickson D.N., J. Am. Chem. Soc., 112, (1990)
  • [4] Miller J.S., Epstein A.J., Reiff W.M., Chem. Rev., 88, (1988)
  • [5] Broderick W.E., Thompson J.A., Day E.P., Hoffman B.M., Science, 249, (1990)
  • [6] Yee G.T., Manriquez J.M., Dixon D.A., McLean R.S., Groski D.M., Flippen R.B., Narayan K.S., Epstein A.J., Miller J.S., Adv. Mater., 3, (1991)
  • [7] Manriquez J.M., Yee G.T., McLean R.S., Epstein A.J., Miller J.S., Science, 252, (1991)
  • [8] Burdett J.K., Canadell E., Organometallics, 4, (1985)
  • [9] Katz T.J., Rosenberger M., O'Hara R.K., J. Am. Chem. Soc., 86, (1964)
  • [10] Bunel E.E., Valle L., Manriquez J.M., Organometallics, 4, (1985)