Conclusions
In this article we have presented some recent achievements of the polyoxometalates in the fields of molecular magnetism and functional molecular materials. In the context of the molecular magnetism we have shown that POMs provide ideal examples of magnetic clusters with coexisting ferro and antiferromagnetic exchange interactions which can be investigated using a variety of magnetic techniques, including the Inelastic Neutron Scattering spectroscopy, to get a thorough characterization of the magnetic levels in these large clusters, and to test the validity of the spin hamiltonians commonly used in magnetism.
In the context of the molecular materials we have shown that these cluster anions can be combined with perylene organic donors to form crystalline radical salts with unprecedented organic packings and large electrical conductivities. On the other hand, we have shown that nanostructured hybrid films formed by monolayers of ferromagnetic polyoxometalates alternating with of mixed-valence TTF-type monolayers can be constructed by using the Langmuir-Blodgett technique. More and more complex systems are expected to be obtained in the future starting from molecular units. POMs have shown to be very useful building blocks in this context.
Chapter PDF
References
For a review presenting the recent developments occurred in this field see for example the special issue devoted to polyoxometalates in Chem. Rev. 98 (1998).
J. M. Clemente-Juan and E. Coronado Magnetic Clusters from Polyoxometalate Complexes Coord. Chem. Rev. 193–195:361 (1999)
E. Coronado and C. J. Gómez-García Polyoxometalate-Based Molecular Materials Chem. Rev. 98:273 (1998).
E. Coronado and C. Mingotaud ybrid Organic/Inorganic Langmuir-Blodgett-Films — A Supramolecular Approach to Ultrathin Magnetic-Films Adv. Mater. 11:869 (1999).
A. Müller, F. Peters, M. T. Pope and D. Gatteschi Polyoxometalates — Very Large Clusters — Nanoscale Magnets Chem. Rev. 98:239 (1998).
C. M. Tourné, G. F. Tourné and F. Zonnevijlle Chiral Polytung stometalates [WM 3 (H 2 O) 2 (XW 9 O 34 ) 2 ]12− (X=M=Zn or Co 10−) and Their M-Substituted Derivatives — Syntheses, Chemical, Structural and Spectroscopic Study of Some D,L Sodium and Potassium-Salts J. Chem. Soc. Dalton Trans. 143 (1991).
L. C. W. Baker and T. P. McCutcheon, Heteropoly Salts Containing Cobalt and Hexavalent Tungsten in the Anion, J. Am. Chem. Soc. 78:4503 (1956); (b) L. C. W. Baker, S. W. Baker, K. Eriks, M. T. Pope, M. Shibata, O. W. Rollins, J. H. Fang and L. L. Koh, A New General Structural Category of Heteropolyelectrolytes. Unusual Magnetic and Thermal Contraction Phenomena, J. Am. Chem. Soc. 88:2329 (1966).
N. Casañ-Pastor, J. Bas, E. Coronado, G. Pourroy and L. C. W. Baker 1st Ferromagnetic Interaction in a Heteropoly Complex [Co ii 4 O 14 (H 2 O) 2 (PW 9 O 27 ) 2 ]10− — Experiment and Theory for Intramolecular Anisotropic Exchange Involving the 4 Co(II) Atoms J. Am. Chem. Soc. 114:10380 (1992); (b) C. J. Gómez-García, E. Coronado and J. J. Borrás-Almenar Magnetic Characterization of Tetranuclear Copper(II) and Cobalt(II) Exchange-Coupled Clusters Encapsulated in Heteropolyoxotungstate Complexes — Study of the Nature of the Ground-States Inorg. Chem. 31:1667 (1992); (c) H. Andres, J. M. Clemente-Juan, M. Aebersold, H. U. Güdel, E. Coronado, H. Büttner, G. Kearly, J. Melero and R. Burriel Magnetic Excitations in Polyoxometalate Clusters Observed by Inelastic Neutron-Scattering — Evidence for Anisotropic Ferromagnetic Exchange Interactions in the Tetrameric Cobalt(II) Cluster [Co- 4 (H 2 O) 2 (PW 9 O 34 ) 2 ]10− — Comparison with the Magnetic and Specific-Heat Properties J. Am. Chem. Soc. 121:10028(1999).
T. J. R. Weakley, The Identification and X-Ray Structure of the Diphosphatotris(nonatungstophosphonato)nonacobaltate(II) Heteropolyanion, J. Chem. Soc. Chem. Commun. 1406 (1984); (b) C. J. Gómez-García, E. Coronado and J. R. Galán-Mascarós Adv. Mater. 6:221 (1994).
H. Andres, J. M. Clemente-Juan, R. Basler, M. Aebersold, H. U. Güdel, J. J. Borrás-Almenar, A. Gaita, E. Coronado, H. Büttner and S. Janssen, Magnetic Polyoxometalates: Anisotropic Antiferro-and Ferromagnetic Exchange Interactions in the Pentameric Cobalt(II) Cluster [Co 3 W(D 2 O) 2 (CoW 9 O 34 ) 2 ]12− A Magnetic and Inelastic Neutron Scattering Study, Inorg.Chem. 40:1943 (2001).
S. Triki, L. Ouahab, D. Grandjean, R. Canet, C. Garrigou-Lagrange and P. Delhaes New Conducting Radical-Cation Salt Based on BEDT-TTF and Substituted Polyoxometalate Anions —(BEDT-TTF) 5 (VW 5 O 19 )6H 2 O Synth. Met. 55–57:2028 (1993); (b) E. Coronado, J. R. Galán-Mascarós, C. Gimenez-Saiz, C. J. Gómez-García and V. N. Laukhin The First Radical Salt of the Polyoxometalate Cluster [P 2 W 18 O 62 )(6-Theta) with bis(Ethylenedithio) Tetrathiafulvalene (Et)-Et 11 (P 2 W 18 O 62 )-3H 2 O Adv. Mater. 8:801(1996).
H. Akamatu, H. Inokuchi and Y. Matsunaga, Organic Semiconductors with High Conductivity. I. Complexes between Polycyclic Aromatic Hydrocarbons and Halogens, Bull.Chem.Soc.Jpn. 29:213 (1956).
H. C. I. Kao, M. Jones and M. M. Labes, Metallic Conductivity in a Perilene·4I 2 Complex, J. Chem. Soc. Chem. Commun. 329 (1979).
D. Schweitzer, I. Henning, K. Bender, H. Endres and H. J. Keller, Organic Metals form Simple Aromatic Hydrocarbons:Perylene Radical Salts, Mol. Crys. Liq. Cryst. 120:213 (1985).
H. J. Keller, D. Nöthe, H. Pritzkov, D. Wehe, M. Werner, P. Koch and D. Schweitzer, Electrochemically Generated Peryleniumylhexafluorophosphate and Hexafluoroarsenate, Mol. Cryst. Liq. Cryst. 62:181 (1980); (b) W. Brütting and W. Riess Peierls Instability and Charge-Density-Wave Transport in Fluoranthene and Perylene Radical-Cation Salts Acta Phys. Pol. A 87:785 (1995).
I. J. Tickle and C. K. Prout, Molecular Complexes. Part XVII. Crystal and Molecular Structure of Perylene-7,7,8,8-Tetracyanoquinodimethane Molecular Complex, J. Chem. Soc. Perkin Trans. 2:720 (1973).
H. Kokado, K. Hasewaga and W. G. Schneider, Photoconduction and Semiconduction in Monocrystals of the Charge-transfer Complex, Perilene-fluoranil, Can.J.Chem. 42:1084 (1964).
J. A. Ayllón, I. C. Santos, R. T. Henriques, M. Almeida, E. B. Lopes, J. Morgado, L. Alcácer, L. F. Veiros and M. T. Duarte Perylene Salts with Tetrahalogenoferrate(III) Anions — Synthesis, Crystal-Structure of [(C 20 H 12 ) 3 ](FeCl 4 ) and Characterization. J Chem. Soc. Dalton Trans. 3543 (1995).
V. Gama, M. Almeida, R. T. Henriques, I. C. Santos, A. Domingos, S. Ravy and J. P. Pouget Low-Dimensional Molecular Conductors (per) 2 M(MNT) 2 , M=Cu and Ni-Low-Conductivity and High-Conductivity Phases J. Phys. Chem. 95:4263 (1991); (b) V. Gama, R. T. Henriques, G. Bonfait, L. C. Pereira, J. C. Waerenborgh, I. C. Santos, M. T. Duarte, J. M. P. Cabral and M. Almeida Low-Dimensional Molecular-Metals (per) 2 M(MNT) 2 (M=Fe and Co) Inorg. Chem. 31:2598 (1992).
M. Almeida and R. T. Henriques in Handbook of Organic Conductive Molecules and Polymers, vol. 1, H. S. Nalwa (ed.), John Wiley, Chinchester, p. 87 (1997).
P. Day, M. Kurmoo, T. Mallah, I. R. Marsden, R. H. Friend, F. L. Pratt, W. Hayes, D. Chasseau, J. Gaultier, G. Bravic and L. Ducasse Structure and Properties of Tris(bis(Ethylenedithio)Tetrathiafulvalenium)Tetrachlorocopper(II)Hydrate, (BEDT-TIF) 3 CuCl 4 .H 2 O—1st Evidence for Coexistence of Localized and Conduction Electrons in a Metallic Charge-Transfer Salt J. Am. Chem. Soc. 114:10722 (1992).
M. Kurmoo, A. W. Graham, P. Day, S. J. Coles, M. B. Hursthouse, J. L. Caulfield, J. Singleton, F. L Pratt, W. Hayes, L. Ducasse and P. Guionneau Superconducting and Semiconducting Magnetic Charge-Transfer Salts— (BEDT-TIF) 4 AFe(C 2 O 4 ) 3 ·C 6 H 5 CN (A=H 2 O, K, NH 4 ) J. Am. Chem. Soc. 117:12209 (1995); (b) H. Kobayashi, H. Tomita, T. Naito, A. Kobayashi, F. Sakai, T. Watanabe and P. Cassoux New Bets Conductors with Magnetic Anions (Bets-Equivalent-to-bis(Ethylenedithio)Tetraselenafulvalene) J. Am.Chem. Soc. 118:368 (1996).
E. Coronado. J. R. Galán-mascarós, C. J. Gómez-García and V. N. Laukhin Coexistence of Ferromagnetism and Metallic Conductivity in a Molecule-Based Layered Compound Nature 408:447 (2000).
L. Ouahab, M. Bencharif, A. Mhanni, D. Pelloquin, J. F. Halet, O. Peña, J. Padiou, D. Grandjean, C. Garrigou-Lagrange, J. Amiell and P. Delhaes Preparations, X-Ray Crystal-Structures, Eh Band Calculations, and Physical-Properties of (TTF) 6 H(XM 12 O 40 )(Et 4 N) (M=W, M o X=P, Si) — Evidence of Electron-Transfer BetweenOrganic Donors and Polyoxometalates Chem. Mater. 4:666 (1992).
(a) C. J. Gómez-García, C. Giménez-Saiz, S. Triki, E. Coronado, P. Le Magueres, L. Ouahab, L. Ducasse, C. Sourisseau and P. Delhaes Coexistence of Magnetic and Delocalized Electrons in Hybrid Molecular Materials — The Series of Organic-Inorganic Radical Salts (BEDT-TIF) 8 (XW 12 O 4- )(Solv) n (X=2H +, B III, Si IV, Cu II, Co II, Fe III Solv=H 2 O, CH 3 CN). Inorg. Chem. 34:4139 (1995); (b) E. Coronado, J. R. Galán-Mascarós, C. Giménez-Saiz, C. J. Gómez-García and S. Triki Hybrid Molecular Materials Based upon Magnetic Polyoxometalates and Organic Pi-Electron Donors — Syntheses, Structures, and Properties of bis(Ethylenedithio)Tetrathiafulvalene Radical Salts with Monosubstituted Keggin Polyoxoanions J. Am. Chem. Soc. 120:4671 (1998).
M. Clemente-León, C. Mingotaud, C. J. Gómez-García, E. Coronado and P. Delhaes Polyoxometalates in Langmuir-Blodgett-Films — Toward New Magnetic-Materials Thin solid films 327–329:439 (1998).
E. Coronado and C. J. Gómez-García, Polyoxometalates: from Magnetic Clusters to molecular Materials, Comments Inorg. Chem. 17:255 (1995).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2002 Kluwer Academic Publishers
About this chapter
Cite this chapter
Clemente-Juan, J.M. et al. (2002). Polyoxometalates: From Magnetic Models to Multifunctional Materials. In: Yamase, T., Pope, M.T. (eds) Polyoxometalate Chemistry for Nano-Composite Design. Nanostructure Science and Technology. Springer, Boston, MA. https://doi.org/10.1007/0-306-47933-8_13
Download citation
DOI: https://doi.org/10.1007/0-306-47933-8_13
Publisher Name: Springer, Boston, MA
Print ISBN: 978-0-306-47359-3
Online ISBN: 978-0-306-47933-5
eBook Packages: Springer Book Archive