Tsunehisa Okuno

Preparation and properties of two-legged ladder polymers based on polydiacetylenes

A novel diacetylene derivative, N,N′-bis[5-(3-tolylaminocarbonyloxy)-1,3-pentadiynyl]-N,N′-diphenyl-1,4-phenylenediamine (1), was prepared, where two diacetylene groups were connected by a 1,4-phenylenediamine moiety. The molecules stacked one-dimensionally and showed solid-state-polymerization reactivity above 80 °C. The decay of the monomers at 100 °C proceeded gradually without a marked induction period and was fully completed after 400 h. The obtained polymer was a crystalline solid judged by powder X-ray diffraction (PXRD) patterns and SEM imaging. The conjugated π-system of the obtained polymer was classified as a two-legged conjugated ladder. The polymer showed a broad absorption from the visible to the near IR region, indicating a decrease in the optical band gap of ca. 1.0 eV, because of the expansion of the π-conjugated system from a one-dimensional system to a ladder. The ladder polymer showed high conductivity after I2 doping from σ293K = 5 × 10−12 S cm−1 to 1.2 × 10−5 S cm−1. The conductivity depended heavily on the pressure of iodine and reached σ373K = 2.3 × 10−1 S cm−1. The activation energy of the ladder polymer was also estimated as 360 meV.

Solid State Polymerization of Diacetylenes Incorporating Ynamine Moiety

Novel ynamine compounds, 5-hydroxy-1-(phenothiazine-10-yl)-1,3-pentadiyne (1), its S-oxide (2) and S-dioxide (3), were prepared. Compound 2 was found to show thermal reactivity to give polydiacetylene, however 1 and 3 did not show any reactivity. Compound 2 stacks along the c axis, forming a columnar structure. The condition of molecular arrangement satisfied Baughmans criterion. Significant intermolecular contact between the oxygen atoms of sulfoxide groups and the adjacent sulfur atoms was recognized.

4-(Prop-2-yn-1-yl-oxy)benzaldehyde.

In the title molecule, C10H8O2, all non-H atoms are essentailly coplanar (r.m.s. deviation = 0.0192 Å), indicating an effective conjugation of the carbonyl group, the benzene ring and the lone pair of the propynyloxy O atom. In the crystal, π–π stacking interactions [centroid–centroid distance = 3.5585 (15) Å] connect molecules into inversion dimers which are linked by Csp—H⋯O=C hydrogen bonds, forming a ladder-like structure.

10-(Prop-1-yn-1-yl)-10H-phenothia-zine.

In the title compound, C15H11NS, the asymmetric unit comprises one half-molecule; a mirror plane passes through the S atom, the ynamine fragment, the methyl C atom and one methyl H atom. The phenothiazine moiety has a butterfly conformation and the central six-membered ring has a boat conformation. The dihedral angle between the benzene rings is 149.40 (4)°. The crystal structure is stabilized by van der Waals interactions.

2-Methyl-3-(10H-pheno-thia-zin-10-yl)buta-1,3-diene-1,1,4,4-tetra-carbo-nitrile.

In the title compound, C21H11N5S, the phenothiazine unit has a butterfly structure, and the central six-membered ring adopts a boat conformation. The dihedral angle between the benzene rings is 127.64 (6)°, which is smaller than those reported for similar compounds because of the steric repulsion between the phenothiazine and its tetracyano-1,3-butadiene substituent. The dicyanovinyl groups are almost orthogonal to one another, making a dihedral angle of 80.58 (6)°. In the crystal, the molecules are aligned along the b axis. Four kinds of weak C—H⋯N interactions are recognized, one of which connects the molecules into a one-dimensional array and the remaining three link these arrays.

10-(6-Hy­droxy­hexa-2,4-diyn-1-yl)-10H-phenothia­zine 5-oxide

The title compound, C18H13NO2S, has two independent molecules (A and B) with similar conformations in the asymmetric unit. Both phenothiazine moieties have a butterfly structure [dihedral angles between benzene rings = 155.17 (7) and 161.71 (7)°, respectively], and the central six-membered rings have a boat form. In the crystal, the A and B molecules stack alternately along the b axis. The A and B molecules are linked by O—H⋯O=S hydrogen bonds, forming zigzag chains along [10-1].

Crystal structure of 4-(prop-2-yn-1-yl-oxy)benzo-nitrile.

In the title compound, C10H7NO, the dihedral angle between the aromatic ring and the prop-2-yn-1-yloxy grouping is 9.47 (10)°. The bond lengths indicate electronic conjugation between the cyano group, the benzene ring and the propynyloxy oxygen atom. In the crystal, a hydrogen bond between the acetylenic C—H atom and the cyano nitrogen atom link the molecules into wave-like [30-1] C(11) chains. These chains are connected by Csp 2—H⋯πac (πac is the acetylinic C—C triple bond) close contacts [2.794 (1) Å], resulting in a rolling sheet structure parallel to the ac plane and aromatic π–π stacking interactions between the sheets [centroid–centroid distance = 3.593 (2) Å] generate a three-dimensional network.

A new polymorph of 1,3-bis­(penta­fluoro­phen­yl)urea

The title compound, C13H2F10N2O, has been previously described in the space group Pbca with Z = 8 [Jai-nhuknan et al. (1997 ▶). Acta Cryst. C53, 455–457]. The current P212121 polymorph was obtained from a tetrahydrofuran solution. The pentafluorophenyl rings make dihedral angles of 50.35 (6) and 54.94 (6)° with the urea fragment, in close accord with those reported for the first polymorph. In the crystal, both of the N—H groups donate H atoms to the same carbonyl O atom, forming a one-dimensional molecular array along the a axis. There are close contacts between perfluorophenyl C atoms within the array [3.228 (3) Å] and halogen bonds are also observed between the arrays [F⋯F = 2.709 (2) and 2.7323 (18) Å].

Transannular S···N interactions in 10-ethynyl-10H-phenothiazine 5-oxide and 5,5-dioxide.

The title compounds, C14H9NOS, (1), and C14H9NO2S, (2), are oxidation products of the parent compound 10-ethynyl-10H-phenothiazine. They differ with respect to transannular interactions, the intramolecular S···N contact being shorter in (2). Intermolecular Csp-H···O hydrogen bonds were detected in both crystals, and (1) was found to form stronger hydrogen bonds. These results are in agreement with the lower acidity of Csp-H in (2), caused by an increase in π-electron density due to the transannular S···N interaction.

9-Ethynyl-9H-carbazole

The title compound, C14H9N, is the second crystallographically characterized example of an ynamine with an H atom in the C-terminal position. There are two independent molecules (A and B) in the asymmetric unit. The structures of both molecules are essentially planar (r.m.s. deviation = 0.0312 and 0.0152 Å). The N—Csp bond lengths are 1.353 (4) and 1.350 (4) Å, and those of the acetylene bonds are 1.189 (4) and 1.190 (4) Å. The Csp—H bond lengths are 0.95 (5) and 0.97 (4) Å. These geometries are consistent with those of the previously reported ynamine characterized by crystallography. In the crystal, the molecules stack along the c axis, forming two kinds of columnar structures. The acetylene C atoms of molecule A have a short contact [3.341 (4) Å and 3.396 (4) Å] with an adjacent molecule A at the C—C bond of the fused part, which originates in π–π stacking interaction; no remarkable spatial contact is recognized within the stacking of molecule B.