Wakako Suzuki

Development of single-component molecular metals based on extended-TTF dithiolate ligands

The novel nickel complex with the extended-TTF dithiolate ligand [Ni(tmdt) 2 ] (tmdt 2- =trimethylenedithiotetrathiafulvalenedithiolate) is the first three-dimensional single-component molecular metal. Structures and physical properties of analogous single-component molecular conductors [Ni(dmdt) 2 ] (dmdt 2- =dimethyltetrathiafulvalenedithiolate), [Ni(eodt) 2 ] (eodt 2- =ethylenedioxytetrathiafulvalenedithiolate) and [Pd(C3-tdt) 2 ] [(C3-tdt) 2- =dipropylthiotetrathiafulvalenedithiolate] were examined. The structure of [Au(tmdt) 2 ] was determined by synchrotron radiation powder diffraction experiments and the MEM/Rietveld analysis. The single-component paramagnetic molecule [Cu(dmdt) 2 ] was also studied to clarify the possibility of single-component magnetic molecular conductors.

Molecular design and development of single-component molecular metals with extended TTF ligands

The novel neutral nickel complex with the extended TTF dithiolato ligand, trimethylenedithiotetrathiafulvalenedithiolate[tmdt 2 m = (S 6 C 9 H 6 ) 2 m ], have been synthesized. The single crystal of [Ni(tmdt) 2 ] was metallic down to 0.6 K. The crystal structure and electronic band structure calculation showed [Ni(tmdt) 2 ] is the first single-component molecular metal with three-dimensional Fermi surfaces. Metallic behavior was also found in the crystal of an analogous molecule, [Ni(dmdt) 2 ][dmdt 2 m = dimethyltetrathiafulvalenedithiolate]. Similar highly conducting systems, [Au(dmdt) 2 ] and the molecular conductor with localized S = 1/2 spins, [Cu(dmdt) 2 ] were also prepared. extended TTF ligand single-component molecular metal three-dimensional molecular metal

Development of Single-Component Molecular Metals and Magnetic Molecular Superconductors

In the design of new functional materials, molecular systems have high advantageous characters. Since the molecule tends to keep its nature even in the assembled state, it seems not so difficult to design the bi-functional systems by combining the molecular building blocks with different characters. A good example may be the magnetic organic conductors composed of organic π donors and magnetic anions. The ability to design a molecule in molecular systems is another advantageous feature. The nature of frontier molecular orbitals, dominating most of the electronic properties of molecular materials, can be controlled to some extent by suitable design of the molecule, which makes, in principle, the rational design of the functional molecular materials. The development of single-component molecular metal may be a good example showing the validity of “frontier orbital design”.

Molecular metals and superconductors based on transition metal complexes with dmit or extended-TTF ligands

The crystal structure of a high-pressure superconductor [(CH 3 ) 2 (C 2 H 5 ) 2 N] [Pd(dmit) 2 ] 2 at 10 kbar was determined by diamond-anvil cell to clarify the origin of unique P-T phase diagram of this system. The doubling of lattice spacing along the Pd(dmit) 2 stack was observed. The novel neutral nickel complex with the extended TTF dithiolato ligand, trimethylenedithiotetrathiafulvalenedithiolate[tmdt 2− =(S 6 C 9 H 6 ) 2− ], have been synthesized. The single crystal of [Ni(tmdt) 2 ] was metallic down to 0.6 K. The crystal structure and electronic band structure calculation showed [Ni(tmdt) 2 ] is the first single-component molecular metal with three-dimensional Fermi surfaces.