Valence delocalisation in a strongly coupled (K_c = 10¹⁴) molecule-bridged cyanodiiron(III,II) species

Abstract

A hybrid between the Prussian Blue and Creutz–Taube mixed valent species is presented in the form of the bmtz-bridged bis[tetracyanoiron(+2.5)] complex 1^3– [bmtz = 3,6-bis(2-pyrimidyl)-1,2,4,5-tetrazine] which exhibits a very large comproportionation constant of 10¹⁴ and a delocalised structure, according to UV–VIS–NIR–IR spectroelectrochemistry in acetonitrile solution.

References

1. (a) W. Kaim, W. Bruns, J. Poppe and V. Kasack, J. Mol. Struct., 1993, 292, 221; (b) H. Taube, Ann. N.Y. Acad. Sci., 1978, 313, 481; (c) D. Astruc, Electron Transfer and Radical Processes in Transition Metal Chemistry, VCH, New York, 1995; (d) Mixed Valency Systems—Applications in Chemistry, Physics and Biology, ed. K. Prassides, Kluwer Academic Publishers, Dordrecht, 1991; (e) M. D. Ward, Chem. Soc. Rev., 1995, 34, 121; (f) N. S. Hush, Coord. Chem. Rev., 1985, 64, 135.
2. H. Vahrenkamp, A. Geiss and G. N. Richardson, J. Chem. Soc., Dalton Trans., 1997, 3643.
3. C. Creutz, Prog. Inorg. Chem., 1983, 30, 1.
4. D. Astruc, Acc. Chem. Res., 1997, 30, 383; B. A. Etzenhouser, M. D. Cavanaugh, H. N. Sprugeon and M. B. Sponsler, J. Am. Chem. Soc., 1994, 116, 2221; H. S. Mountford, L. O. Spreer, J. W. Otvos, M. Calvin, K. J. Brewer, M. Richter and B. Scott, Inorg. Chem., 1992, 31, 717.
5. F. Felix, U. Hauser, H. Siegenthaler, F. Wenk and A. Ludi, Inorg. Chim. Acta, 1975, 15, L7; F. Felix and A. Ludi, Inorg. Chem., 1978, 17, 1782; K. J. Brewer, W. R. Murphy, Jr. and J. D. Petersen, Inorg. Chem., 1987, 26, 3376.
6. W. Kaim and J. Fees, Z. Naturforsch., Teil B, 1995, 50, 123.
7. J. Poppe, M. Moscherosch and W. Kaim, Inorg. Chem., 1993, 32, 2640.
8. E. Waldhör, J. Poppe, W. Kaim, E. Cutin, M. Garcia Posse and N. E. Katz, Inorg. Chem., 1995, 34, 3093; E. Waldhör, W. Kaim, J. A. Olabe, L. D. Slep and J. Fiedler, Inorg. Chem., 1997, 36, 2969.
9. W. Kaim, Coord. Chem. Rev., 1987, 76, 187.
10. A. Stebler, J. H. Ammeter, U. Fürholz and A. Ludi, Inorg. Chem., 1984, 23, 2764.
11. W. Kaim, W. Bruns, S. Kohlmann and M. Krejcik, Inorg. Chim. Acta, 1995, 229, 143.
12. T. T. Chin, S. R. Lovelace, W. E. Geiger, C. M. Davis and R. N. Grimes, J. Am. Chem. Soc., 1994, 116, 9359.
13. W. Bruns, W. Kaim, E. Waldhör and M. Krejcik, J. Chem. Soc., Chem. Commun., 1993, 1868; W. Bruns, W. Kaim, E. Waldhör and M. Krejcik, Inorg. Chem., 1995, 34, 663.