Department of Chemistry, William Mong Institute of Nano Science and Technology, Bioengineering Graduate Program, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China, and Department of Polymer Science and Engineering, Key Laboratory of Macromolecular Synthesis and Functionalization of the Ministry of Education, Institute of Biomedical Macromolecules, Zhejiang University, Hangzhou 310027, China

Acetylenic polymers: syntheses, structures, and functions.

Disclosed is an organic electroluminescent device having long life, while exhibiting high luminous efficiency. Also disclosed are an illuminating device and a display, each using such an organic electroluminescent device. In the organic electroluminescent device, a compound represented by the general formula (A) which is suitable as a host material for a phosphorescent metal complex is used at least in one sublayer of a light-emitting layer.

Organic electroluminescent element, display device and lighting device

Xerographic photoreceptors charge acceptance and dark discharge photoinduced discharge photogeneration theories photogeneration in organic solids charge transport theories charge transport in polymers and related materials experimental techniques photoreceptor preparation photoreceptors fatigue summary and future requirements.

Organic Photoreceptors for Imaging Systems

https://www.rsc.org/suppdata/CC/b7/b717764j/b717764j.pdf

An imidazole-functionalized polyacetylene: convenient synthesis and selective chemosensor for metal ions and cyanide

In the chromatographic separation of enantiomers the order of elution is determined by the strength of diasteromeric interactions between the components of the mixture and a chiral stationary phase. For analytical purposes, it is ideal to have the minor component elute first, whereas in the preparative mode a faster elution of the major component is desirable. Here we describe a stationary phase constructed from a polyacetylene that bears 2,2'-bisphenol-derived side chains in which chirality can be switched in the solid state prior to use. Both the macromolecular helicity of the polymer backbone and the axial chirality of the side chains can be switched in the solid state by interaction with a chiral alcohol, but importantly are maintained after removal of the chiral alcohol because of a memory effect. The chiral stationary phase thus prepared was used to separate the enantiomers of trans-stilbene oxide with the enantiomer elution order determined by the preseparation treatment.

Switchable enantioseparation based on macromolecular memory of a helical polyacetylene in the solid state

Stereoregular polymerization of (o-ethoxyphenyl)acetylenes (OEPA) was performed using a [Rh(norbornadiene)Cl]2 catalyst in the presence of triethylamine to give poly((o-ethoxyphenyl)acetylene) (POEPA) bearing a cis-transoid form under mild conditions. The polymer underwent isomerization from the predominant cis form to the trans form when compressed at 200 kg/cm2 at room temperature. The polymers, obtained before and after the compression, were characterized in detail using laser Raman, diffuse reflective UV, ESR, and X-ray diffraction. The data suggested that the isomerization of the resulting polymer from the cis-transoid to the trans-transoid form was induced to give rise to the conjugated trans-planar zigzag structures, where unpaired electrons are stabilized as mobile electrons called solitons. The formation of the soliton radicals was confirmed by the motional narrowing of the line width observed in the ESR spectra of the compressed polymer. The trans conjugation length, n, (CC)n generated by the co...

Pressure-induced cis to trans isomerization of aromatic polyacetylenes. 2. Poly((o-ethoxyphenyl)acetylene) stereoregularly polymerized using a Rh complex catalyst

Stereoregular polymerization of (p-nitrophenyl)acetylene (pNPA) was performed using [Rh(norbornadiene)Cl]2 and [Rh(cyclooctadiene)Cl]2 catalysts to give poly((p-nitrophenyl)acetylene) (PpNPA), with a cis−transoid form under mild conditions. The polymer underwent isomerization from the predominant cis to trans form when compressed at 200 kg/cm2 at room temperature. The polymers, obtained before and after compression, were characterized using IR, CP MAS 13C NMR, ESR, and diffuse reflective UV methods. The data suggest that the isomerization of the resulting polymer from cis−transoid to trans−transoid form gives a conjugated trans planar zigzag structure. The trans conjugation lengths, n, in the polymer chain (CC)n after the compression were estimated as ca. 29 or 50, when polymers obtained with methanol or triethylamine as the polymerization solvents were used. The trans sequence length obtained by thermal treatment of the cis−transoid polymer was also found to have less conjugated sequences than that of th...

Pressure-Induced Cis to Trans Isomerization of Poly((p-nitrophenyl)acetylene) Prepared Using Rh Complex Catalysts. Extension of π Conjugation Length

Stereoregular polymerization of (p-3-methylbutoxy)phenylacetylene (p3MBPA) was successfully performed with a [Rh(NBD)Cl] 2 catalyst to afford poly(p-3-methylbutoxy)phenylacetylene (Pp3MBPA) having a cis-transoid form in high yields when ethanol or 1-butanol in the presence of triethylamine was used as the polymerization solvent. The resulting cis polymer was composed of a pseudohexagonal structure called columnar as π-conjugated self-assembly or π-conjugated self-organization in the solid state. The columnar polymer underwent isomerization from the predominant cis to trans form when compressed at 100 kg/cm 2 at room temperature. The pristine polymer and the compressed polymer were characterized in detail using 1 H NMR, wide-angle X-ray diffraction, laser Raman, electron spin resonance, and diffuse reflective UV-vis methods. Consequently, the data showed that the absorption maximum of the π-conjugated columnar polymer appears in an extremely longer wavelength region, ie., at 490 nm, despite the cis form compared with 450 nm of the amorphous cis form. In the solid state, a large blue shift of the absorption maximum was found to be induced when the columnar structure was destroyed by compression to produce a trans-transoid form which has planar zigzag π-conjugation sequences. The pristine columnar polymer showed the λ max as an entire absorption at notably longer wavelength so that the chromophore of the π-conjugated columnar polymer is not to be simply attributed to the primary structure, e.g., a repeated double-single bond structure, but rather should be ascribed to that of aggregated molecules called the π-conjugated columnar as self-assembly or self-organization. This explanation is a new concept with respect to the color of π-conjugated columnar polymers and is very important for the molecular design of electroluminescense (EL) and nonlinear optical (NLO) materials which are used at present in the solid state.

Origin of color of π-conjugated columnar polymers. 1. Poly(p-3-methylbutoxy)phenylacetylene prepared using a [Rh(norbornadiene)Cl]2 catalyst

o-Trifluoromethyl(phenylacetylene) (oTFMPA) was successfully polymerized by a Rh complex, [Rh(norbornadiene)Cl]2 catalyst, in the presence of triethylamine as the polymerization solvent under mild conditions. Structural differences between the Rh polymer and the Mo polymer prepared with a metathesis initiator, MoOCl4−n-Bu4Sn−EtOH, using the same monomer were compared using laser Raman, 1H and 19F NMR, solution and diffuse reflective UV, and electron spin resonance (ESR) methods. The Rh complex produces the aromatic polyacetylene bearing regular head-to-tail, ordered trans sequences where more mobile unpaired electrons generated through the rotational scission of the cis CC bonds are stabilized, although the Rh catalyst is known to selectively generate the cis−transoid isomer. The Mo-based initiators produce also complete trans−transoid polyacetylene involving irregular head-to-head and/or tail-to-tail units of ca. 32% disordered trans sequences, where less mobile unpaired electrons are stabilized in the i...

Polymerization of o-Trifluoromethyl(phenylacetylene) Initiated by [Rh(norbornadiene)Cl]2 and MoOCl4−n-Bu4Sn−EtOH Catalysts. Formation of Order and Disorder Trans Sequences

The stereospecific polymerization of o- and p-methoxyphenylacetylenes (MOPAs) with [Rh(norbornadiene)Cl] 2 as a catalyst in the presence of an organic base (triethylamine) at 30°C is reported, together with the detailed characterization using resonance Raman, diffuse reflection UV, and ESR spectroscopic methods. The resulting polymers were shown to selectively have a cis-transoid form. It was found, interestingly, that the resultant aromatic polyacetylenes in the cis form are easily isomerized to those in the trans form when a pressure of ca. 100∼200 kg/cm 2 was exerted on the solid polymers at room temperature.

Pressure-induced cis to trans isomerization of poly(ortho- and para-methoxyphenylacetylene)s prepared by [rh(norbornadiene)Cl]2 catalyst. A Raman, UV, and ESR study

Takeyuki Sone

Papers

Pressure-induced cis to trans isomerization of aromatic polyacetylenes. 2. Poly((o-ethoxyphenyl)acetylene) stereoregularly polymerized using a Rh complex catalyst

Pressure-Induced Cis to Trans Isomerization of Poly((p-nitrophenyl)acetylene) Prepared Using Rh Complex Catalysts. Extension of π Conjugation Length

Origin of color of π-conjugated columnar polymers. 1. Poly(p-3-methylbutoxy)phenylacetylene prepared using a [Rh(norbornadiene)Cl]2 catalyst

Polymerization of o-Trifluoromethyl(phenylacetylene) Initiated by [Rh(norbornadiene)Cl]2 and MoOCl4−n-Bu4Sn−EtOH Catalysts. Formation of Order and Disorder Trans Sequences

Pressure-induced cis to trans isomerization of poly(ortho- and para-methoxyphenylacetylene)s prepared by [rh(norbornadiene)Cl]2 catalyst. A Raman, UV, and ESR study