Kosuke Ueyama

Syntheses and electrical resistivities of TTF and TSF salts with tris(oxalato)silicate, -germanate, and -stannate

Abstract Several tetrathiafulvalene (TTF) and tetraselenafulvalene (TSF) salts of tris(oxalato)silicate, -germanate, and -stannate, (TTF) x [X(C 2 O 4 ) 3 ]·nCH 3 CN (x = 2 and n = 0.5 for M = Si and Ge, and x = 2.8 and n = 0 for M = Sn) and (TSF) 2 [M(C 2 O 4 ) 3 · nCH 3 CN (n 0 for M = Si, Sn and n = 0.5 for M = Ge), have been prepared by the reaction of (TTF) 3 (BF 4 ) 2 or (TSF) 3 (BF 4 ) 2 with [R 4 N] 2 [M(C 2 O 4 ) 3 ] (R = Et or n-Bu) in acetornitrile. Electrocrystallization for the TTF[Et 4 N] 2 [Sn(C 2 O 4 ) 3 ] and TSF[Et 4 N] 2 [Ge(C 2 O 4 ) 3 ] systems in acetonitrile afforded (TTF) 2.8 [Sn(C 2 O 4 ) 3 ]·0.5SH 3 CN and (TSF) 2 [Ge(C 2 O 4 ) 3 ], respectively. Electrical resistivities of the TTF salts as compacted samples at 25°C fall in the range 10 4 –10 5 Ω cm and those of the TSF salts in the range 10 3 –10 4 Ω cm. Electronic reflectance spectra of the TTF and TSF salts show bands at 13 30013 600 cm −1 and 11 40012 500 cm −1 due respectively to the (TTF ??? ) 2 and (TSF ??? ) 2 dimers. In addition, (TTF) 2.8 [Sn(C 2 O 4 ) 3 exhibited a band at 8900 cm −1 , ascribed to a charge transfer transition between neutral TTF and the TTF ??? radical cation. All the salts display weakly diamegnetic properties, consistent with the appearance of anisotropic weak ESR signals attributable to the TTF ??? and TSF ??? radical cations.

Preparation and electrical resistivities of tetrathiafulvalen (TTF) and tetraselenafulvalen salts with the [SnR2Cln]2-n anions (n = 3 or 4: R = Et or Ph) and X-ray crystal structure of [TTF]3[SnEt2Cl4]

Abstract Tetrathiafulvalen (TTF) and tetraselenafulvalen (TSF) salts with diorganochloro-stannate anions, [TTF][SnEt2Cl3] (1), [TTF]2[SnPh2Cl4] (2), [TTF]3[SnEt2Cl4] (3), [TTF]3.3[SnPh2Cl4] (4), [TSF]2[SnPh2Cl4] (5) and [TSF]3.3[SnPh2Cl4] (6), were prepared by the reactions of [TTF or TSF]3[BF4]2 with SnR2Cl2 (R = Et or Ph) in the presence of [Ph3PCH2Ph]Cl and by electrocrystallization of TTF or TSF in acetonitrile containing SnR2Cl2 and [Ph3PCH2Ph]Cl. All the salts behave as semiconductors with electrical resistivities of the order of 10–108 Ω cm as compacted samples at 25°C. Electronic reflectance spectra of the simple salts 1, 2 and 5, show a band due to the dimeric(TTF+)2 or (TSF+)2 unit in the 12,200–12,800-cm−1 region. The complex salt 3 exhibits a TTF+/TTF° charge-transfer (CT) band at 8700 cm−1, and the remaining complex salts, 4 and 6, both display CT bands between the radical cations and between the radical cation and the neutral donor molecule. The crystal structure of 3 was determined by a single-crystal X-ray diffraction. The tetragonal crystal, space group I4cm, has cell dimensions a = 11.710(3) A, c = 25.242(7) A, and Z = 4. The structure was solved by the heavy-atom method and refined to a final R value of 0.082 for 479 independent reflections with >F° > 3σ(F). TTF molecules exist as trimers, in which a slight lateral shift from the eclipsed TTF overlap occurs, although TTF molecules are arranged with equal spacing between them. The trimer units are located perpendicularly to each other, forming a two-dimensional layer. The [SnEt2Cl4]2− anion is disordered with respect to the two SnEt and two SnCl bonds.

Preparation and properties of TTF and TSF salts with planar platinum(II) and copper(II) oxalate anions

Abstract Tetrathiafulvalene (TTF) and tetraselenafulvalene (TSF) salts with bis(oxalato)platinate, dichloro(oxalato)platinate, and bis(oxalato)cuprate anions were prepared by the reaction of [TTF] 3 [BF 4 ] 2 or [TSF] 3 [BF 4 ] 2 with the oxalatometallates, either in acetonitrile or in dimethyl sulfoxide. These salts contain neutral TTF 0 or TSF 0 as well as the TTF• + or TSF• + radical cation. Electronic reflectance spectra of the salts show a band due to dimeric (TTF• + ) 2 or (TSF• + ) 2 in the 13100–14000 or 10500–12300 cm −1 region, as well as a band due to a TTF• + /TTF 0 or TSF• + /TSF 0 charge transfer transition in the 8600–8900 cm −1 range. X-Ray photoelectron spectra of the TTF salts with oxalato-platinates indicate the occurrence of some negative charge transfer from the TTF moiety to the platinate anion. It is also suggested that the planar bis(oxalato)cuprate anions in the TTF and TSF salts exist as a dimer based on the ESR spectra. All the salts behave as semiconductors with the electrical resistivities in the order 10 2 –10 4 Ω cm as compacted samples at 25 °C.

X-ray crystal structure and properties of tris(tetrathiafulvalenium)hexachloroplatinate

Abstract The title salt has been prepared by the diffusion of tetrathiafulvalene (TTF) and [NBun4]2[PtCl6] in acetonitrile. Crystals (black plates) are tetragonal, space group P4/mbm, with a=11.757(2), c=11.707(2) A, and Z=2. The block-diagonal least-squares refinement, based on 804 independent reflections with ∣Fo∣> 3σ(F), yields an R factor of 0.11. The structure is comprised of TTF-trimer units which are arranged perpendicularly to each other, forming a two-dimensional layer with somewhat close sulfur- sulfur contact among the trimers. The salt exhibits the electrical resistivity of 87 Ω cm as a compacted pellet at 25 °C. Binding energies of platinum 4f electrons of the [PtCl6]2− anion suggest an extreme reduction from the platinum(IV) state.

Crystal Structures and Electrical Properties of TTF Salts with TIN(IV) Chloride Anions

Several TTF salts with tin(IV) chloride anions have been prepared: [TTF][SnR2Cl3] (R = Me and Et), [TTF]2[SnR2Cl4] (R = Cl and Ph), [TTF]3[SnR2Cl4] (R = Cl, Me, and Et), and [TTF]3.3[SnPh2Cl4]. The...

Electrochemical reductions of substituted pyridinium 2-pyridylcarbonylmethylides, their Pt(II) complexes, and substituted n-(2-pyridylcarbonyl)methylpyridinium perchlorates

The title pyridinium salts and pyridinium ylide-platinum(II) complexes have been reduced through a one-electron process at more positive potentials by 0.3

Electrical properties and configurations of TTF and TSF salts with cis-dialkylbis(oxalato)stannate(IV) anions

0.6 V than the corresponding ylides. Both the reduced pyridinium salts and Pt(II)-ylide complexes reacted with dioxygen, followed by elimination of the N-methylene and ylide protons to form pyridinium ylides and Pt(II)-pyridinium ylide complexes containing the three-coordinate ylide carbon atom, respectively.

An sp2 ylide carbon-to-metal bonding: x-ray molecular structure of [PtII(NH2CH2CH2NH2)(C5H4NC(O)CNC5H3(CH3)2-3,5)]ClO4-2H2O

Abstract TTF and TSF salts with [ cis -R 2 Sn(C 2 O 4 ) 2 ] 2− , [TTF or TSF] 2.0−4.0 [ cis -R 2 Sn(C 2 O 4 ) 2 ] (R = Me and Et; C 2 O 4 2− = the oxalate anion) were prepared by the reaction of [TTF of TSF] 3 [BF 4 ] 2 with [ cis -R 2 Sn(C 2 O 4 ) 2 ] 2− in acetonitrile, and by electrolysis of TTF or TSF in acetonitrile solutions containing [NBu n 4 ] 2 [ cis -R 2 Sn(C 2 O 4 ) 2 ] as electrolytes. All the salts behave as typical seminconductors with electrical resistivities of 1 × (10 1 −10 7 ) Ω cm at 25°C as compacted pellets. TTF or TSF molecules (D) in the complex salts are stacked in a column with D• + /D• + and D• + /D O interactions in the solids, as discussed on the basis of electronic reflectance spectra. Electronic interactions between TTF and TSF moieties and the polarized [ cis -R 2 Sn(C 2 O 4 ) 2 ] 2− anions were observed in the infrared spectra.

Emission and electrochemical studies of 2-pyridylcarbonylmethylide-rhenium(I) complexes

An X-ray structure analysis for the title complex obtained by the reaction of PtIICL2(C5H4NC(O)CH+NC5H3(CH3)2-3.5) with ethylenediamine in water has revealed the presence of an ylide carbon atom which is coordinated to the platinum(II) ion with an sp2 configuration.

X-Ray crystal structures and properties of tris(tetrathiafulvalenium) tetrachlorodimethylstannate(IV) and tetrathiafulvalenium trichlorodimethylstannate(IV)

Abstract Re(I)Br(CO)3(2-pyridylcarbonylmethylide) and Re(I)Br(CO)3(2-acetylepyridine) were prepared by reactions of Re(I)Br(CO)5 with 2-pyridylcarbonylmethylides, C5H4NC(O)−CH+Z [+Z = +PPh3 (Yp), +AsPh3 (YAs), +SMe2 (Ys) and +NC5H4R−4 (YN-R; R = CN, Ph, H and Me)], and 2-acetylpyridine. These complexes are concluded to assume an octahedral geometry containing the chelation by the carbonyl oxygen and pyridyl nitrogen atoms and the facial-coordination of metal carbonyl groups on the basis of IR and 1H-NMR spectra. Although the 2-acetylpyridine complex gave no emission, the Yp, YAs, and Ys complexes showed an emission due to the metal-to-ligand charge transfer (MLCT) transition at 77 K in MeOH/EtOH (1 : 4 v/v). On the other hand, the YN-R complexes showed emissions due to both the MLCT and the intraligand CT transitions. All the present ylide complexes were oxidized at +0.71 to +0.82 V vs Ag/Ag+ in acetonitrile. The Yp, YAs, and YS complexes were reduced at − 1.91 to − 2.00 V, while reduction of the YN-R complexes occurred on the pyridinium ring of the ylides at less negative potentials ( − 1.68 to − 1.04 V).