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Departament de Ciències Experimentals

Development of Trinuclear Molybdenum Cluster Chalcogenides with Outer Dithiolate Ligands as Magnetic Building Blocks for the Preparation of Molecular Conductors. Rosa Llusar. Departament de Ciències Experimentals. Universitat Jaume I. Castelló (SPAIN). Outline.

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Departament de Ciències Experimentals

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  1. Development of Trinuclear Molybdenum Cluster Chalcogenides with Outer Dithiolate Ligands as Magnetic Building Blocks for the Preparation of Molecular Conductors Rosa Llusar Departament de Ciències Experimentals Universitat Jaume I Castelló (SPAIN)

  2. Outline • Introduction to inorganic molecular conductors • The Mo3Q7cluster unit • Dithiolate and diselenolate cluster complexes with Mo3Q7cluster units • Single component molecular conductors and magnets based on the Mo3Q7cluster core: transport and magnetic properties • Conclusions

  3. D0.8+ A0.4- A0.4- Characteristics: - Donor-acceptor partial electron transfer - Structures with separate donor and acceptor stacks - Internal HOMO-LUMO electron transfer “S.....S interactions” First Inorganic Molecular Superconductor (TTF) [Ni(dmit)2]2 Cassoux et al Acad. Sci. Ser. II 1986, 205

  4. Characteristics: - Internal HOMO-LUMO electron transfer - Small HOMO-LUMO energy gap - Large intermolecular 3D interactions Single Component Molecular Metals Ni(tmdt)2 metal • (300 K)= 400 S cm-1 Kobayashi et al. Science, 2001, 285 “Short intermolecular transverse S…S contacts”

  5. Characteristics : - Small HOMO-LUMO energy gap - 1 D Semiconductor built by magnetic units Single Component Molecular Conductors Mo3S7(dmit)2 Semiconductor • (300 K)= 25 S cm-1 χT(300 K)= 0.8 emu K mol-1 Llusar et al. J. Am. Chem Soc. 2004, 12076 “S…S interaction along the “c” direction”

  6. Outline • Introduction to inorganic molecular conductors • The Mo3Q7cluster unit • Dithiolate and diselenolate cluster complexes with Mo3Q7cluster units • Single component molecular conductors and magnets based on the Mo3S7cluster core: transport and magnetic properties • Conclusions

  7. Qeq Qeq Qax Qax Anion The Mo3S7 Cluster Unit : Characteristics Easy modification of the outer ligands Possibility of Mo3Q4Q’3 and Mo3Q4 cluster cores Potential to participate in Q ···Q interactions • Very labile terminal Brligands • The Qequatorial(in plane) atoms are more labile • Ability to bind anions to their Qaxial atoms

  8. Fedin Inorg. Chim. Acta, 1991, 81 (PPh4)Br 300 oC M= Mo, W Q=S The Mo3Q7 Cluster Unit: Synthetic precursors Mechanochemical activation K2C2O4 [M3(3-Q)(-Q2)3(C2O4)3]2- Sokolov Inorg. Chem, 2005, 81

  9. The Mo3Q7 Cluster Unit: Synthetic precursors Mechanochemical activation K2C2O4 [M3(3-Q)(-Q2)3(C2O4)3]2- • reactor vibrations frequency 25 Hz, • vertical movements amplitude 1 cm • duration of the treatment 15 h Sokolov Inorg. Chem. 2005, 81

  10. Fedin Inorg. Chim. Acta, 1991, 81 (PPh4)Br 300 oC M= Mo, W Q=S HBr (ac) Q=S, Se Unpublished results The Mo3Q7 Cluster Unit: Synthetic precursors Mechanochemical activation K2C2O4 [M3(3-Q)(-Q2)3(C2O4)3]2- Sokolov Inorg. Chem, 2005, 81

  11. Outline • Introduction to inorganic molecular conductors • The Mo3Q7cluster unit • Dithiolate and diselenolate cluster complexes with Mo3Q7cluster units • Single component molecular conductors and magnets based on the Mo3Q7cluster core: transport and magnetic properties • Conclusions

  12. oxidation Br Brsubstitution by redox active ligands p.e. dithiolates Qeq Dithiolates Br Qax ¨e¨ ¨a¨ 1,2 dithione 1,2 alkenedithiolate Coordination of Dithiolates to the Mo3Q7 Unit Electron precise [Mo3Q7Br6]2-

  13. Synthesis of Trinuclear Mo3S7 Dithiolates [Mo3S7Br6]2- (TBA)2[Zn(1,2-dithiolate)2] or (1,2-dithiolate)SnBu2 or Na2(1,2-dithiolate) 1,2-benzenedithiol

  14. Synthesis of Trinuclear Mo3Se7 Dithiolates [Zn(dmit)2]2- + ES-MS of [Mo3S7(ptdt)3](TBA)2 ES-MS of [Mo3S7(ptdt)3](TBA)2

  15. Structure of [Mo3Q7(dithiolate/diselenolate)3]2- [Mo3S7(dsit)3]2- Dimer formation

  16. Trinuclear [Mo3Q7(dithiolate)3]2-clusters: Structure (TBA)2[Mo3S7(dmit)3] and (TBA)2[Mo3S7(dsit)3] C 2/c Chains (Ph4P)2[Mo3S7(dmit)3] P-1 Chains

  17. Voltammogram of [Mo3S7(bdt)3]2- Trinuclear Mo3Q7 clusters: Redox properties Voltammogram of [Mo3S7(dmit)3]2- Oxidation E vs Ag/AgCl

  18. Outline • Introduction to inorganic molecular conductors • The Mo3Q7cluster unit • Dithiolate and diselenolate cluster complexes with Mo3Q7cluster units • Single component molecular conductors and magnets based on the Mo3Q7cluster core: transport and magnetic properties • Conclusions

  19. Oxidation of (TBA)2[Mo3S7(dithiolate/diselenolate)3] I2 electroxidation Mo3S7 Mo3Se7 Mo3S7 [Mo3S7(dmit)3] and [Mo3S7(dmid)3] are isostructural

  20. a b c Structure of [Mo3S7(dmit)3] Packing Cavity diameter 10 Å Semiconductor • rt= 25 S cm-1 E a= 16 meV χTrt= 0.8 emu K mol-1 Llusar et al. JACS 2004, 12076

  21. Small E gap AFM band structure of [Mo3S7(dmit)3] “e” E “a” Higher dispersion along “c” “e” “a” G=(0, 0, 0) X=(a*/2, 0, 0) K=(a*/3, a*/3, 0) Z=(0, 0, c*/2) 1D molecular conductor EFM- EAFM = 0.02 eV / molec

  22. Conductivity in [Mo3Q7(dithiolate)3] r vs. T Semiconductor

  23. -2 e- [Mo3Q7(dithiolate)3]2- [Mo3Q7(dithiolate)3] HOMO ¨e¨ ¨a¨ Magnetism in [Mo3S7(dithiolate/diselenolate)3] cT vs. T [Mo3S7(dmit)3] [Mo3S7(dmid)3] [Mo3Se4(Se/S)3(dmit)3] [Mo3S7(bdt)3] [Mo3S7(dsit)3] [Mo3S7(tdas)3] [Mo3S7(bdt-S2CS)3] Antiferromagnetic coupling

  24. Two unpaired e- delocalized over three sites c MODEL Localized spin chain with random spin distribution of S=0 (1/3 probability) S=1 (2/3 probability) Magnetic properties modelling J= - 66 cm-1; J’= - 13.2 cm-1 g= 1.92 TIP= 2 x 10-3 emu/mol Spin frustrated extended network

  25. Conclusions • Several anionic complexes of formula [Mo3Q7(dithiolate)3]2- have been synthesized and oxidized to afford neutral clusters. • Paramagnetic neutral [Mo3Q7(dithiolate)3] species have been isolated for the dmit and dmid dithiolates. • [Mo3S7(dmit)3] and [Mo3S7(dmid)3] are 1D semiconductors where the conducting electrons are also responsible of the magnetic properties. • The dispersion along “c” has been atributted to π interactions between the dithiolate sulfur orbitals. • The magnetic lattice in [Mo3S7(dmit)3] and [Mo3S7(dmid)3] presents two competing antiferromagnetic interactions to give a spin frustrated extended network.

  26. Acknowledgments Santiago Uriel Marta Feliz Sonia Triguero Cristian Vicent Eva Guillamón

  27. Acknowledgments • Carlos Gómez (U. de València) • Eugenio Coronado (U. de València) • Juan M. Clemente (U. de València) • Enric Canadell (Institut de Materials de Barcelona) • Benoit Braïda (Institut de Materials de Barcelona) • Vladimir Fedin (RAS of Novosibirsk) • Maxim Sokolov (RAS of Novosibirsk) • Olga Gerasko (RAS of Novosibirsk) • Artyom Gushchin(RAS of Novosibirsk) • Marc Fourmigué (CIMMA, University of Angers) • Narcis Avarvari (CIMMA, University of Angers) • Manuel Almeida (ITN, Portugal) • Elsa Lobes (ITN, Portugal)

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