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Laboratoire Chimie, Ingénierie Moléculaire et Matériaux d’Angers (CIMMA)

Chiral Molecular Conductors Based on TTF-Oxazoline Derivatives. Narcis AVARVARI. Laboratoire Chimie, Ingénierie Moléculaire et Matériaux d’Angers (CIMMA) UMR 6200 CNRS-Université d'Angers. ISCOM 2005 Key West, USA. C 2 symmetry. R D/L ( I,B ) = R 0 {1 + b B 2 + c D/L I•B }.

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Laboratoire Chimie, Ingénierie Moléculaire et Matériaux d’Angers (CIMMA)

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  1. Chiral Molecular Conductors Based on TTF-Oxazoline Derivatives Narcis AVARVARI Laboratoire Chimie, Ingénierie Moléculaire et Matériaux d’Angers (CIMMA) UMR 6200 CNRS-Université d'Angers ISCOM 2005 Key West, USA

  2. C2 symmetry R D/L(I,B) = R0 {1 + b B2 + cD/LI•B} Chiral tetrathiafulvalenes : Objectives I. Chiral molecular conductors 1. Enantiopure forms are less disordered in the crystalline state Influence on the conducting properties Many examples of chiral TTF’s ●●● but lack of complete series of (R), (S) and (±) conducting salts of the same precursor for useful comparisons 2. Recent reports by Rikken et al. on electrical magneto-chiral anisotropy (eMChA) effects Chiral SWNT Krstić, Rikken et al. J. Chem. Phys. 2002, 117, 11315 cD = - cL Electrical resistance handedness of the chiral conductor eMChA effect (very weak)

  3. Chiral tetrathiafulvalenes : Objectives II. Chiral redox active ligands for enantioselective catalysis The control of the metal complexes reactivity upon oxidation - reduction Influence on the catalytic processes? substitutionally inert redox-switchable ligands redox-switchable hemilabile ligands reactive fragment redox-switchable ligands C. A. Mirkin et al. Angew. Chem. Int. Ed. Engl.1998, 37, 894.

  4. TTF-OX TTF-PHOX chiral molecular conductors chiral resolution of anions coordination chemistry catalysis Chiral tetrathiafulvalenes Our choice chiral oxazoline steric hindrance M electronic properties phosphine redox active unit EDT-TTF more interactions in the solid state due to additional sulfur atoms

  5. Geometry optimization DFT B3LYP 6-31+G(d) Tetrathiafulvalene-Oxazolines TTF-OX Conformational issues ? more stable Two energy minima DE(s-trans – s-cis) = - 1.41 Kcal/mole Planar conformations HOMO

  6. Tetrathiafulvalene-Oxazolines TTF-OX Synthesis J. Mat. Chem.1999, (9)10, 2373 TTF-OX C.Réthoré, M. Fourmigué, N. Avarvari, Chem. Commun. 2004, 1384.

  7. TTF-OX (R)-Me, monoclinic P21 (S)-Me, monoclinic P21 only the s-trans conf is observed (R)-iPr, orthorhombic P212121 (S)-iPr, orthorhombic P212121 CD spectra of TTF-(iPr)OX C.Réthoré, M. Fourmigué, N. Avarvari, Tetrahedron 2005, in ASAP

  8. TTF-OX: chiral conductors A series of racemic and chiral mixed-valence salts (OX-TTF)2AsF6 S---S (Å) intra-stack 3.67-3.80 inter-stack 3.29 racemic salt b-type slab metallic behavior down to 170 K

  9. TTF-OX: chiral conductors A series of racemic and chiral mixed-valence salts (OX-TTF)2AsF6 racemic salt enantiopure (R) salt Triclinic P1 (no. 1) a = 6.3918(7) Å b = 7.5020(9) Å c = 17.941(2) Å a = 83.20(1)° b = 86.64(1)° g = 85.55(1)° V = 850.60(17) Å3 Triclinic P-1 (no. 2) a = 6.3993(6) Å b = 7.4969(7) Å c = 17.9524(16) Å a = 83.58(1)° b = 86.51(1)° g = 85.50(1)° V = 852.04(14) Å3 enantiopure (R) salt metallic behavior down to 200 K intra-stack 3.69-3.80 inter-stack 3.27-3.31 S---S (Å)

  10. E (eV) TTF-OX: chiral conductors Band structure calculation for ((R)-OX-TTF)2AsF6 b intrastack 0.529/0.337 eV open Fermi surface b interstack 0.086/0.034 eV for (BEDT)2I3 b intrastack 0.439/0.287 eV b intrastack 0.164/0.024 eV Pressure dependence of the conductivity

  11. TTF-OX: chiral conductors A series of racemic and chiral mixed-valence salts (OX-TTF)2AsF6 racemic salt enantiopure (R) salt Structural disorder effect C.Réthoré, N. Avarvari, E. Canadell, P. Auban-Senzier, M. Fourmigué, J. Am. Chem. Soc. 2005, 127, 5748.

  12. Geometry optimization DFT B3LYP 6-31+G(d) TTF-OX: chiral conductors s-cis s-trans more stable DE(s-trans – s-cis) = - 1.38 Kcal/mole SOMO CD spectra of (OX-TTF)2AsF6

  13. TTF-(SMe)OX Towards a control of the OX conformation through a 1,5-interaction Target compound or Synthesis

  14. (S)-iPr 2.85 Å O–––S1,5 interaction Geometry optimization s-cis s-trans DFT B3LYP 6-31+G(d) 2.95 Å 2.88 Å HOMO HOMO HOMO-9 HOMO-4 TTF-(SMe)OX Two minima DE(s-trans – s-cis) = + 0.26 Kcal/mole s-trans s-cis

  15. TTF-(SMe)OX DFT B3LYP 6-31+G(d) C=C dist DE(s-trans – s-cis) = + 0.63 Kcal/mole A 1.366(12) B 1.325(12) C 1.359(13) I 0.428 eV II 0.338 eV III 0.002 eV IV 0.454 eV IV A 6:1 salt with Mo6Cl14 C s-trans III B II A s-cis I A B s-trans C b-type slabs

  16. B B A C C A B B C A C A TTF-(SMe)OX Why B stays neutral ? Conductivity Thermopower electrostatic interaction oxazoline Semiconducting behavior C. Réthoré, M. Fourmigué, E. Lopes, M. Almeida, E. Canadell, N. Avarvari, unpublished results

  17. Role of structural disorder on the conductivity • Magneto-chiral anisotropy effect in molecular conductors • Chiral resolution of racemic mixtures of anions TTF-OX and Derivatives Why the chirality of TTF-OX and Derivatives is interesting? Enantioselective homogenous catalysis with TTF-PHOX • Allylic substitution, Imines hydrogenation, etc. • Influence of the TTF oxidation state on the catalytic process Chiral molecular materials Work in progress●●● New complete series of mixed valence salts Use of paramagnetic anions Use of thiazolines instead of oxazolines (s-trans more stable) Metallic complexes of TTF-(SMe)-OX and TTF-(PR2)-OX Use of TTF-bis-oxazolines (TTF-BOX)

  18. Acknowledgements Céline Réthoré PhD student Dr. Augustin Madalan Postdoc Dr. Marc Fourmigué Collaborations Dr. E. Canadell ICMAB, Barcelona, Spain Dr. P. Auban-Senzier LPS, Orsay University, France CNRS - Université d'Angers Région Pays de la Loire Dr. M. Almeida Dr. E. Lopes ITN, Sacavem,Portugal Prof. R. Llusar E. Guillamon Torres Univ. of Castellon, Spain LNCMP, Toulouse, France Dr. G. L. J. A. Rikken Dr. F. Agbossou-Niedercorn Dr. I. Suisse Laboratoire de Catalyse, Lille, France

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