Hatsue Tamura

Preparation and properties of C8H4S8-platinum(II) complexes and electrical conductivities of their oxidized species and X-ray crystal structure of C8H4S8(CH2CH2CN)2 as a pro-ligand compound

Abstract Using the C8H4S82− ligand [2-[(4,5-ethylenedithio)-1,3-dithiole-2-ylidene]-1,3-dithiole-4,5-dithionate(2-)] as an extended π-electron system, [NBun4]2[Pt(C8H4S8)2] and Pt(Et2S)2(C8H4S8) were prepared. They were oxidized by the ferrocenium, the decamethylferrocenium cation or iodine to form [NBun4]8[Pt(C8H4S8)2] (x=0.05−0.4) and Pt(C8H4S8) (Et2S)0.3I1.8, which exhibited electrical conductivities of 1.1–6.9 S cm−1, measured for compacted pellets at room temperature. The crystal structure of the pro-ligand compound. C8H4S8(CH2CH2CN)2, revealed a one-dimensional array of dimerized molecules constructed with some sulfur-sulfur non-bonded contacts.

Oxidation properties of Co(η5-C5H5)(C8H4S8) and Co(L)(C3S5) (L=η5-C5H5 and η5-C5Me5) and crystal structure of Co(η5-C5Me5)(C3S5)Br

Abstract Co(η5-C5H5)(C8H4S8) (C8H4S82−=2-{(4,5-ethylenedithio)-1,3-dithiole-2-ylidene}-1,3-dithiole-4,5-dithiolate(2−)) was prepared by a reaction of Co(η5C5H5)(CO)I2 with Na2C8H4S8 in ethanol. It was oxidized by iodine in benzene and by the ferrocenium cation in dichloromethane to afford [Co(η5-C5H5)(C8H4S8)]·I3 and [Co(η5-C5H5)(C8H4S8)][PF6]0.7, respectively, with the ligand-centered oxidation, which exhibited electrical conductivities of 0.19 and 0.16 S cm−1 for compacted pellets at r.t. Co(η5-C5H5)(C3S5) and Co(η5-C5Me5)(C3S5) (C3S52−=4,5-disulfanyl-1,3-dithiole-2-thionate(2−)) were oxidized by 0.5 molar amounts of bromine to give one-electron oxidized species, which were disproportionated to the unoxidized and the two-electron oxidized species in solution. The crystal structure of the one-electron oxidized species, Co(η5-C5Me5)(C3S5)Br, revealed a one-dimensional array of the molecules through sulfur–sulfur non-bonded contacts. This complex exhibits a strong antiferromagnetic interaction in the solid state, but behaves essentially as an insulator.

Preparation of Pt(II) and Pd(II) complexes coordinated with both a diimine ligand and a sulfur-rich dithiolate ligand and electrical conductivities of their oxidized species and X-ray crystal structure of Pd(N-butyl-pyridine-2-carbaldimine)(C3S5)

Abstract Pt(L)(C8H4S8) [L=2,2′-bipyridine (bpy) and N-butyl-pyridine-2-carbaldimine (Bu-pya); C8H4S82−=2-{(4,5-ethylenedithio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithionate(2-)], Pt(bpy)(C10–C6S8) [C10–C6S82−=2-{bis(dodecylthio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate (2-)], Pd(Bu-pya)(C8H4S8), and Pd(Bu-pya)(C3S5) [C3S52−=4,5-disulfanyl-1,3-dithiol-2-thionate(2-)] were prepared. They showed intense electronic absorption bands due to an intramolecular mixed metal/ligand-to-ligand charge transfer transition which is sensitive to a solvent. They exhibit oxidation potentials of −0.18 and +0.35 V (versus Ag/Ag+) with oxidation of the dithiolate ligand. They were oxidized by iodine or TCNQ (7,7,8,8-tetracyano-p-quinodimethane) to afford [Pt(L)(C8H4S8)](I3)x (x=0.9–1.0), [Pt(L)(C8H4S8)](TCNQ)y (y=0.6–0.8) (L=bpy, Bu-pya and C10–C6S8) and [Pd(Bu-pya)(C8H4S8)]·I5.1 and [Pd(Bu-pya)(C8H4S8)](TCNQ)0.4. The [Pt(L)(C8H4S8)]-oxidized complexes behave as electrical conductors with conductivities of 1.4×10−5–6.5×10−3 S cm−1 measured for compacted pellets at room temperature, while the [Pd(Bu-pya)(C8H4S8)]-oxidized species exhibit conductivities of (1.4–3.2)×10−3 S cm−1. The X-ray crystal structure of Pd(Bu-pya)(C3S5) revealed a one-dimensional array of the molecules constructed with some sulfur–sulfur non-bonded contacts.

Preparation and properties of dinuclear bis[dicarbonyl(cyclopentadienyl)]diiron(II) complexes with SS coupled, dimerized sulfur-rich dithiolate ligands

Abstract Dinuclear bis[dicarbonyl(cyclopentadienyl)]diiron(II) complexes with the bridging, SS coupled, dimerized sulfur-rich dithiolate ligands, [Fe(C5H5)(CO)2(C3S5C3S5)Fe(C5H5)(CO)2] (1) and [Fe(C5H5)(CO)2(C8H4S8C8H4S8)Fe(C5H5)(CO)2] (2), were prepared by reactions of [Fe(C5H5)(CO)2I] with Na2[C3S5] or Na2[C8H4S8] [C3S52−=4,5-disulfanyl-1,3-dithiole-2-thionate(2-) and C8H4S82−=2-{(4,5-ethylenedithio)-1,3-dithiole-2-ylidene}-1,3-dithiole-4,5-dithionate(2-)] in ethanol, followed by oxidation in the air. The dinuclear structures of these complexes were established by the X-ray crystallography for 1 and by molecular weight and the electrospray mass spectra of 2. Complex 2 exhibited the (C8H4S8)2 ligand-centered oxidation at a low potential, and reacted with iodine to afford the oxidized species [Fe(C5H5)(CO)2(C8H4S8-C8H4S8)Fe(C5H5)(CO)2]Ix (x=6.0 and 10.5), of which the oxidized I10.5-species containing I3− and I5− ions exhibited electrical conductivity of 1.7×10−4 S cm−1 measured for a compacted pellet at room temperature.

Crystal structure of copper(II)mellitate, [Cu3.5C6(COO)5(COOH)(OH)2(H2O)8.5]·4.5H2O

The crystal structure of copper(II)mellitate, Cu3.5C12H29O27, has been determined by X-ray analysis. The complex crystallizes in the orthorhombic space groupIba2, with unit-cell dimensionsa=19.274(3),b=21.054(7),c=12.956(4) Å. The structure was deduced by the direct method with the help of the Patterson method and refined by the block-diagonal least-squares technique to a finalR value of 0.037 for 2995 observed reflections. Among six carboxyl groups of mellitic acid, five groups lose protons and form coordinate bonds to four copper atoms, and the remaining group forms hydrogen bonds to the water of crystallization and coordinated water. The configuration around copper is distorted-pyramidal, with the Cu-O bond distances of 1.896(7) to 2.425(7) Å.

Preparation and oxidation of polarized Au(III) complexes having both the C-deprotonated-2-phenylpyridine (ppy) and a sulfur-rich dithiolate ligand and X-ray crystal structure of [Au(η2-C,N-ppy)(η2-S,S-C8H4S8)]·0.5DMF

Abstract [Au(ppy)(C8H4S8)] [ppy−=C-deprotonated-2-phenylpyridine(1-), C8H4S82−=2-{(4,5-ethylenedithio)-1,3-dithiole-2-ylidene}-1,3-dithiole-4,5-ditholate(2-)] and [Au(ppy)(C10–C6S8)] [C10–C6S82−=2-{bis(decylthio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5- dithiolate(2-)] were prepared. They showed an intense electronic absorption band due to an intramolecular mixed metal/ligand-to-ligand charge transfer transition which is sensitive to a solvent. They exhibit first oxidation potentials of −0.06 to +0.20 V (vs. Ag/Ag+) due to the dithiolate ligand-centered oxidation. They were oxidized by iodine or TCNQ (7,7,8,8-tetracyano-p-quinodimethane) to afford [Au(ppy)(C8H4S8)](I3) and [Au(ppy)(C10–C6S8)](I3) containing the I3− ion, [Au(ppy)(C8H4S8)](TCNQ)0.6 and [Au(ppy)(C10–C6S8)](TCNQ)0.5 containing the TCNQ − radical anion. Their oxidized complexes behave as electrical conductors with electrical conductivities of 2.0×10−2– 4.0×10−2 S cm−1 measured for compacted pellets at room temperature. The X-ray crystal structure of [Au(ppy)(C8H4S8)]·0.5DMF revealed a two-dimensional array of the molecules with some sulfur–sulfur non-bonded contacts.

η5-C5H5- and η5-C5Me5-metal complexes (M=Zr(IV) and Hf(IV)) with the sulfur-rich dithiolate C8H4S8 ligand and high electrical conductivities of their oxidized species

Abstract Zr(η 5 -C 5 H 5 ) 2 (C 8 H 4 S 8 ), [NMe 4 ][Zr(η 5 -C 5 H 5 )(C 8 H 4 S 8 ) 2 ], [NMe 4 ][Zr(η 5 -C 5 Me 5 )(C 8 H 4 S 8 ) 2 ], and [NMe 4 ][Hf(η 5 -C 5 Me 5 )(C 8 H 4 S 8 ) 2 ] (C 8 H 4 S 8 2− =2-{(4,5-ethylenedithio)-1,3-dithiole-2-ylidene}-1,3-dithiole-4,5-dithiolate(2-)) were prepared by reactions of Zr(η 5 -C 5 H 5 ) 2 Cl 2 , Zr(η 5 -C 5 H 5 )Cl 3 , Zr(η 5 -C 5 Me 5 )Cl 3 or Hf(η 5 -C 5 Me 5 )Cl 3 with [NMe 4 ] 2 (C 8 H 4 S 8 ) in tetrahydrofuran. They were oxidized by iodine or TCNQ (7,7,8,8-tetracyano- p -quinodimethane) in dichloromethane or in acetone to afford 1.0-, 1.3- or 1.8-electron oxidized complexes, [Zr(η 5 -C 5 H 5 ) 2 (C 8 H 4 S 8 )] + , [Zr(η 5 -C 5 H 5 )(C 8 H 4 S 8 ) 2 ] 0 , [M(η 5 -C 5 Me 5 )(C 8 H 4 S 8 ) 2 ] 0.3+ and [M(η 5 -C 5 Me 5 )(C 8 H 4 S 8 ) 2 ] 0.8+ (M=Zr(IV) and Hf(IV)) species having the I 3 − ion or the TCNQ − radical anion as a counter ion, with the C 8 H 4 S 8 ligand-centered oxidation. They exhibited electrical conductivities of 1.6×10 −1 –7.6×10 −4 S cm −1 measured for compacted pellets at room temperature. Particularly, [Zr(η 5 -C 5 H 5 ) 2 (C 8 H 4 S 8 )] + and [M(η 5 -C 5 Me 5 )(C 8 H 4 S 8 ) 2 ] 0.3+ (M=Zr(IV) and Hf(IV)) complexes as well as [Ti(L)(C 8 H 4 S 8 ) 2 ] 0.3+ (L=η 5 -C 5 H 5 and η 5 -C 5 Me 5 ) species showed high electrical conductivities (0.010–0.16 S cm −1 ).

Diastereomers of copper(II) complexes exhibiting difference in coordination geometry by R- or S-1-phenylethylamine ligands in the solid state and structural conversion of crystals into solutions

Abstract Crystal structures and electronic and circular dichroism (CD) spectra of copper(II) complexes, meso trans-[CuL2(R-phenea)(S-phenea)] (1) and optically active trans-[CuL2(S-phenea)2] (2) (L=5,5-diphenylhydantoinate and phenea=1-phenylethylamine), are reported. The present complexes are the first diastereomers that are different in the degree of tetrahedrally distorted square planar [CuN4] coordination geometries, depending on chirality of phenea ligands. In the solid states, the distortion angles θim and θam defined by the angles which CuN(L) and CuN(phenea) made with the mean coordination plane are θim=12.5° and θam=10.1° for 1 and θim=6.6° and θam=8.4° for 2, respectively. Considerably large distortion of the [CuN4] chromophore of 1 is attributed to alternate arrangement (methyl–phenyl–(Cu)–methyl–phenyl) of substituent groups in phenea ligands, in contrast with symmetric arrangement (methyl–phenyl–(Cu)–phenyl–methyl) for 2. The diffuse reflectance spectra of 1 and 2 in the solid states exhibit a peak at 17 500 and 18 500 cm−1, respectively, and the lower wavenumber peak of 1 is consistent with larger distorted [CuN4] chromophore. In contrast, the absorption spectra of 1 and 2 in chloroform solutions exhibit a peak at 16 100 and 16 000 cm−1, respectively. Then, the similar spectra reflect structural similarity between 1 and 2 in solutions. For the first time, we have successfully estimated the distortion angles in solution to be θim=13° and θam=11° by angular overlap model on the basis of analyses of the CD spectrum of 2.

Crystal structure and magnetic properties of [NMe4]4[Mn2(C3S5)4] (C3S2−5 = 4,5-dimercaptoc-1,3-dithiole-2-thionate)

Abstract The crystal structure of [NMe4]4[Mn2(C3S5)4] (C3S2−5 =4,5-dimercapto-1,3-dithiole-2-dithiole-2-thionate(2−) has been determined by X-ray analysis. The comlex crystallizes in the othorhombic space group Pbca (N0. 61) with a = 23.699(2), b = 22.107(2), c = 10.106(2) A , V = 5294.6(13) A 3 and Z = 8 (for an assymetric (NMe4]2[Mn(C3S5)2] unit). The structure was refined to R (Rw) = 6.2% (6.7%) using 3122 observed reflections with |Fo|>;sσ(F)0. The [Mn2(C3S5)4]4− anion has a centrosymmetric binuclear structure. Each Mn(II) atom is located in a slightly distorted trigonal-bipyramiadl coordination environment bonded to four sulfur atoms of the two C23S5 ligands and to one sulfur atom of the other centrosmmetrically related Mn(C3S5 moiety. The intermolecular S3.S contacts (3.545 A) build up a three-dimensional network of anions. The magnetic susceptibilities in the temperature range 4.2–100 K are well reproduced by the equation for the binuclear structure with J = −5.1 cm−1 and g = 2.00. A weak antiferromagnetic interaction operates between the Mn(II) ions bridging sulfur atoms.

Reaction of oxazoles. Formation of abnormal Diels–Alder adducts of 5-methoxy-4-(p-nitrophenyl)oxazoles with tetracyanoethylene, and X-ray crystal structure of one of the products

The reaction of 2-alkyl or -aryl substituted 5-methoxy-4-(p-nitrophenyl)oxazoles (1) with tetracyanoethylene gave 2-substituted methyl 3,3,4,4-tetracyano-5-(p-nitrophenyl)-4,5-dihydro-3H-pyrrole-5-carboxylates (2) as formal [3 + 2] cycloadducts; these were produced via a zwitterionic mechanism involving oxazole ring opening.