(Dibenzoylmethanato)boron difluoride derivatives containing triphenylamine moieties: a new type of electron-donor/π-acceptor system for dye-sensitized solar cells.

(Dibenzoylmethanato)boron difluoride derivatives containing triphenylamine moieties were synthesized as a new type of electron-donor/π-acceptor system. These new compounds exhibited long-wavelength absorptions in the UV/Vis spectra, and reversible oxidation and reduction waves in cyclic voltammetry experiments. Their amphoteric redox properties are based on their resonance hybrid forms, in which a positive charge is delocalized on the triphenylamine moieties and a negative charge is localized on the boron atoms. Molecular orbital (MO) calculations indicate that their HOMO and LUMO energies vary with the number of phenylene rings connected to the difluoroboron-chelating ring. This is useful for optimizing the HOMO and LUMO levels to an iodine redox (I(-)/I3(-)) potential and a titanium dioxide conduction band, respectively. Dye-sensitized solar cells fabricated by using these compounds as dye sensitizers exhibited solar-to-electric power conversion efficiencies of 2.7-4.4 % under AM 1.5 solar light.

Bis(tetra-n-butyl-ammonium) bis-(5,6-dicyano-pyrazine-2,3-dithiol-ato-κS,S')palladium(II).

In the title complex, (C(16)H(36)N)(2)[Pd(C(6)N(4)S(2))(2)], the centrosymmetric dianion is planar, with an r.m.s. deviation of 0.034 (8) Å. The Pd(II) atom, lying on an inversion center, has a square-planar coordination geometry, with Pd-S bond lengths of 2.276 (3) and 2.294 (3) Å.

Synthesis and properties of terthiophene and bithiophene derivatives functionalized by BF2 chelation: a new type of electron acceptor based on quadrupolar structures.

Terthiophene and bithiophene derivatives functionalized by BF(2) chelation were synthesized as a new type of electron acceptor, and their properties were compared to those of bifuran and biphenyl derivatives. These new compounds are characterized by quadrupolar structures due to resonance contributors generated by BF(2) chelation. The bithiophene derivative has a strong quadrupolar character compared with the bifuran and biphenyl derivatives because their hydrolytic analyses indicated that the bithiophene moiety has a larger on-site Coulomb repulsion than the others. The terthiophene derivative has a smaller on-site Coulomb repulsion than the bithiophene derivative due to the addition of a thiophene spacer. These BF(2) complexes exhibit long-wavelength absorptions and according to measurements of ionization potentials and absorption edges they have energetically low-lying HOMOs and LUMOs. The crystal structure of the bithiophene derivative is of the herringbone type, with short F···S and F···C contacts affording dense crystal packing. n-Type semiconducting behaviour was observed in organic field-effect transistors based on these BF(2) complexes.

An unsymmetrical tetrathiafulvalene with a fused 1,2,5-thiadiazole ring and methylthio groups.

The title compound, 5-(4,5-dimethylthio-1,3-dithiol-2-ylidene)-1,3-diaza-2,4,6-trithiapentalene (4,5-dimethylthio [1,2,5]thiadiazolotetrathiafulvalene, molecular formula C(8)H(6)N(2)S(7)) crystallizes in the P2(1)/n space group with one molecule in the asymmetric unit. The molecular framework is planar within 0.19 A. The molecules form a head-to-tail type of pi-stacking dimer with an interplanar distance is 3.50(1) A, where methylthio groups face away from each other. The molecules are also linked by weak intermolecular S...S heteroatom interactions [3.497(1) and 3.572(1) A] to construct a unique one-dimensional molecular tape structure.

Synthesis, crystal structure, and electron-accepting property of the BF2 complex of a dihydroxydione with a perfluorotetracene skeleton.

A BF(2) complex containing an octafluorotetracene moiety was synthesized as a new type of electron acceptor. This compound exhibits a long-wavelength absorption based on the perfluorotetracene skeleton and high electron affinity due to its quadrupolar structure enhanced by fluorination. In the crystal, the molecules are arranged with short F...pi and F...F contacts affording a dense crystal packing. The BF(2) complex exhibited n-type semiconducting behavior.

A linear chain of water molecules accommodated in a macrocyclic nanotube channel.

A macrocyclic tetramer of 2-phenyl-1,3,4-oxadiazole was synthesized, and its self-assembly was investigated. The macrocycle was stacked to form a one-dimensional (1D) columnar structure containing water molecules. The nanotube self-assembled into a bundle, which grew into a molecular wire. The association of the water molecules in the tubular cavity resulted in shielding of the 1D chain of water molecules by the nanotube; these macrocyclic nanotube channels are promising candidates for nanotechnological applications.

(3Z,3'Z)-3,3'-(Ethane-1,2-diyl-idene)-bis[isobenzofuran-1(3H)-one].

The title compound, C(18)H(10)O(4), has been isolated as an impurity in commercially available 6,11-dihydr-oxy-5,12-naphth-acenedione. The title compound exhibits yellow fluorescence in the solid state. The mol-ecule has crystallographic inversion symmetry and is planar, with an r.m.s. deviation of 0.031 (1) Å. The crystal structure is stabilized by C-H⋯O hydrogen bonds and π-π stacking inter-actions between 3-methyl-eneisobenzofuran-1(3H)-one units [inter-planar distance 3.43 (1) Å].

1,4-Bis[(3,5-dimethoxy-phen-yl)ethyn-yl]benzene.

The title compound, C(26)H(22)O(4), is a derivative of 1,4-bis-(phenyl-ethyn-yl)benzene substituted by four meth-oxy groups on the terminal benzene rings. The mol-ecule is almost planar with an r.m.s. deviation of 0.266 Å. The dihedral angles between the two terminal benzene rings and the central benzene ring are 7.96 (6) and 13.32 (7)°. In the crystal structure, mol-ecules aggregate via C-H⋯O inter-actions, forming mol-ecular tapes along the a axis, which aggregate to form a herring-bone structure.

5,5'-Di-4-pyridyl-2,2'-(5-tert-butyl-m-phenyl-ene)bis-(1,3,4-oxadiazole).

The title compound, C(24)H(20)N(6)O(2), is a novel 1,3,4-oxadiazole derivative which has potential as an electron-transporting material in organic electroluminescent (EL) devices. In the crystal, the mol-ecular framework is almost planar with an r.m.s. deviation of 0.091 (4) Šand it exists in an E form. Intra-molecular C-H⋯O and C-H⋯N hydrogen bonds are observed between the benzene and 1,3,4-oxadiazole rings. The tert-butyl group is disordered over two sites, with occupancy factors of 0.78 (1) and 0.22 (1) for the major and minor orientations, respectively. In the crystal structure, mol-ecules aggregate via C-H⋯N inter-actions, forming mol-ecular tapes along the b axis, which aggregate to form a mol-ecular sheet via C-H⋯N inter-actions.

5-Isopropyl-idene-1,3-dithiolo[4,5-d][1,3]dithiole-2-thione.

The title compound, C(7)H(6)S(5), contains a 5-yl-idene-1,3-dithiolo[4,5-d][1,3]dithiole-2-thione framework, which is an important synthetic precursor of multi-dimensional organic superconductors and conductors. The mol-ecular framework is planar with an r.m.s. deviation of 0.012 Šfor the non-H atoms. In the crystal structure, mol-ecules are linked by short inter-molecular S⋯S inter-actions [3.501 (5) and 3.581 (4) Å], constructing a zigzag mol-ecular tape network along the c axis.

5-(1,3-Dithiolo[4,5-d][1,3]dithiol-2-yl-idene)-1,3-dithiolo[4,5-c][1,2,5]thia-diazole: an unsymmetrical tetra-thia-fulvalene with fused 1,2,5-thia-diazole and 1,3-dithiole rings.

The title unsymmetrical tetra-thia-fulvalene (TTF), C(7)H(2)N(2)S(7), contains fused 1,2,5-thia-diazole and 1,3-dithiole rings and is a component mol-ecule for conducting organic solids. The TTF mol-ecule is disordered crystallographically over two orientations related by an inversion center, where each site is half-occupied. The mol-ecule is almost planar with an r.m.s. deviation of 0.096 Å. In the crystal structure, mol-ecules are linked by short inter-molecular S⋯S inter-actions [3.47 (2), 3.507 (8) and 3.517 (13) Å].

Effect of a tridentate ligand on the structure, electronic structure, and reactivity of the copper(I) nitrite complex: role of the conserved three-histidine ligand environment of the type-2 copper site in copper-containing nitrite reductases.

It is postulated that the copper(I) nitrite complex is a key reaction intermediate of copper containing nitrite reductases (Cu-NiRs), which catalyze the reduction of nitrite to nitric oxide (NO) gas in bacterial denitrification. To investigate the structure-function relationship of Cu-NiR, we prepared five new copper(I) nitrite complexes with sterically hindered tris(4-imidazolyl)carbinols [Et-TIC = tris(1-methyl-2-ethyl-4-imidazolyl)carbinol and iPr-TIC = tris(1-methyl-2-isopropyl-4-imidazolyl)carbinol] or tris(1-pyrazolyl)methanes [Me-TPM = tris(3,5-dimethyl-1-pyrazolyl)methane; Et-TPM = tris(3,5-diethyl-1-pyrazolyl)methane; and iPr-TPM = tris(3,5-diisopropyl-1-pyrazolyl)methane]. The X-ray crystal structures of all of these copper(I) nitrite complexes were mononuclear eta(1)-N-bound nitrite complexes with a distorted tetrahedral geometry. The electronic structures of the complexes were investigated by absorption, magnetic circular dichroism (MCD), NMR, and vibrational spectroscopy. All of these complexes are good functional models of Cu-NiR that form NO and copper(II) acetate complexes well from reactions with acetic acid under anaerobic conditions. A comparison of the reactivity of these complexes, including previously reported (iPr-TACN)Cu(NO2) [iPr-TACN = 1,4,7-triisopropyl-1,4,7-triazacyclononane], clearly shows the drastic effects of the tridentate ligand on Cu-NiR activity. The copper(I) nitrite complex with the Et-TIC ligand, which is similar to the highly conserved three-histidine ((His)3) ligand environment in the catalytic site of Cu-NiR, had the highest Cu-NiR activity. This result suggests that the (His)3 ligand environment is essential for acceleration of the Cu-NiR reaction. The highest Cu-NiR activity for the Et-TIC complex can be explained by the structural and spectroscopic characterizations and the molecular orbital calculations presented in this paper. Based on these results, the functional role of the (His)3 ligand environment in Cu-NiR is discussed.

Diethyl 2,3-dihydro-thieno[3,4-b]-1,4-dioxine-5,7-dicarboxyl-ate.

The title compound, C(12)H(14)O(6)S, is a dicarboxylic acid diethyl ester of 3,4-ethyl-enedioxy-thio-phene, which is a component of electrically conductive poly(3,4-ethyl-enedioxy-thio-phene) (PEDOT). The ethyl-ene group is disordered over two sites with occupancy factors 0.64 and 0.36. Both the carbonyl groups are coplanar with the thio-phene ring. The mol-ecules form centrosymmetric dimers with an R(2) (2)(12) coupling by inter-molecular C-H⋯O hydrogen bonds [3.333 (5) Å] at the ethoxy-carbonyl groups. The dimer units are arranged to form a ribbon-like mol-ecular sheet.

3,8-Bis(4-chloro-phen-yl)-4,7-dimethyl-tricyclo-[4.2.2.0]deca-3,7-diene.

The title tricyclic diene, C(24)H(22)Cl(2), is the product of thermal ring-opening of a corresponding basketane (penta-cyclo-[4.4.0.0(2,5).0(3,8).0(4,7)]deca-ne) derivative. The cyclo-butene ring is planar to within 0.0032 (12) Šand its geometry is normal. The two 4-chloro-phenyl groups are oriented in an approximately face-to-face conformation with a dihedral angle of 44.14 (6)° between them. The 4-chloro-phenyl group bonded to the cyclo-butene ring lies almost in the plane of the cyclo-butene ring, with a dihedral angle of 8.29 (17)° between the ring planes. The average intra-molecular C⋯C distance between the two C=C bonds is 2.92 Å. In the crystal structure, the mol-ecules are well separated with no close C-H⋯Cl or C-H⋯π inter-molecular inter-actions.

1,4-Bis[(2,6-dimethoxy-phen-yl)ethyn-yl]benzene.

The title compound, C(26)H(22)O(4), is a derivative of 1,4-bis-(phenyl-ethyn-yl)benzene substituted by four meth-oxy groups at the terminal benzene rings. The asymmetric unit consists of two half-molecules; one centrosymmetric molecule is planar but the other is non-planar, with dihedral angles of 67.7 (1)° between the central benzene ring and the terminal benzene rings. In the crystal structure, mol-ecules form a zigzag mol-ecular network due to π-π [the inter-planar and centroid-centroid distances between the benzene rings are 3.50 (1) and 3.57 (1) Å, respectively] and C-H⋯π inter-actions (2.75 Å). Introduction of the four meth-oxy groups results in the supra-molecular architecture.

5,5-Bis(4-methoxy-phen-yl)-2,8-bis-[3-(trifluoro-meth-yl)phen-yl]-5H-cyclo-penta-[2,1-b:3,4-b']dipyridine.

The title compound, C(39)H(26)F(6)N(2)O(2), showed two melting transitions 477.4 and 506.5 K in a differential scanning calorimetry (DSC) study. The first of these can be attributed to a melting phase transition arising from the rotation of two trifluoro-methyl groups. In the crystal structure, both trifluoro-methyl groups are disordered over two sites with occupancy factors of 0.660 (17) and 0.340 (17) for the major and minor orientations, respectively. The introduction of trifluoro-methyl groups inhibits π-stacking between the diaza-fluorene (cyclo-penta-[2,1-b:3,4-b']dipyridine) units. Three short F⋯O contacts between 2.80 (3) and 2.95 (1) Šare observed in the crystal structure.

63Cu NMR spectroscopy of copper(I) complexes with various tridentate ligands: CO as a useful 63Cu NMR probe for sharpening 63Cu NMR signals and analyzing the electronic donor effect of a ligand.

63Cu NMR spectroscopic studies of copper(I) complexes with various N-donor tridentate ligands are reported. As has been previously reported for most copper(I) complexes, 63Cu NMR signals, when acetonitrile is coordinated to copper(I) complexes of these tridentate ligands, are broad or undetectable. However, when CO is bound to tridentate copper(I) complexes, the 63Cu NMR signals become much sharper and show a large downfield shift compared to those for the corresponding acetonitrile complexes. Temperature dependence of 63Cu NMR signals for these copper(I) complexes show that a quadrupole relaxation process is much more significant to their 63Cu NMR line widths than a ligand exchange process. Therefore, an electronic effect of the copper bound CO makes the 63Cu NMR signal sharp and easily detected. The large downfield shift for the copper(I) carbonyl complex can be explained by a paramagnetic shielding effect induced by the copper bound CO, which amplifies small structural and electronic changes that occur around the copper ion to be easily detected in their 63Cu NMR shifts. This is evidenced by the correlation between the 63Cu NMR shifts for the copper(I) carbonyl complexes and their nu(C[triple bond]O) values. Furthermore, the 63Cu NMR shifts for copper(I) carbonyl complexes with imino-type tridentate ligands show a different correlation line with those for amino-type tridentate ligands. On the other hand, 13C NMR shifts for the copper bound 13CO for these copper(I) carbonyl complexes do not correlate with the nu(C[triple bond]O) values. The X-ray crystal structures of these copper(I) carbonyl complexes do not show any evidence of a significant structural change around the Cu-CO moiety. The findings herein indicate that CO complexation makes 63Cu NMR spectroscopy much more useful for Cu(I) chemistry.

(E)-2-(2,6-Dichloro-phen-yl)-2-(phenyl-imino)acetamide.

In the title compound, C(14)H(10)Cl(2)N(2)O, which is an important synthetic precursor of a human immunodeficiency virus type 1 (HIV-1) inhibitor, the dihedral angle between the 2,6-dichloro-phenyl ring and the phenyl ring is 69.4 (1)°. In the crystal structure, the mol-ecules form centrosymmetric dimers via N-H⋯O hydrogen bonds with an R(2) (2)(8) motif. The dimers are connected by inter-molecular C-H⋯O and C-H⋯π inter-actions.

6,11-Dihydroxy-naphthacene-5,12-dione.

The mol-ecule of the title compound, C(18)H(10)O(4), is centrosymmetric and planar. A long phenolic O-H bond is observed [1.19 (9) Å], which is involved in an intra-molecular hydrogen bond between the phenolic and quinonoid O atoms. The mol-ecules pack in a herringbone pattern and are linked to each other via inter-molecular C-H⋯O hydrogen bonds (2.73-2.77 Å).

Synthesis, characterization and FET properties of novel dithiazolylbenzothiadiazole derivatives.

Dithiazolylbenzothiadiazoles easily obtained have high electron affinity and the FET device of a trifluoromethylphenyl derivative exhibited a good n-type performance with high electron mobility.