Synthesis and properties of novel soluble polyamides having ether linkages and laterally attached p‐terphenyl units

A new ether‐bridged aromatic dicarboxylic acid, 2′,5′‐bis(4‐carboxyphenoxy)‐p‐terphenyl ( 3 ), was synthesized by the aromatic fluoro‐displacement reaction of p‐fluorobenzonitrile with 2′,5′‐dihydroxy‐p‐terphenyl in the presence of potassium carbonate, followed by alkaline hydrolysis. A set of new aromatic polyamides containing ether and laterally attached p‐terphenyl units was synthesized by the direct phosphorylation polycondensation of diacid 3 with various aromatic diamines. The polymers were produced with high yields and moderately high inherent viscosities (0.44–0.79 dL/g). The polyamides derived from 3 and rigid diamines, such as p‐phenylenediamine and benzidine, and a structurally analogous diamine, 2′,5′‐bis(4‐aminophenoxy)‐p‐terphenyl, were semicrystalline and insoluble in organic solvents. The other polyamides were amorphous and organosoluble and could afford flexible and tough films via solution casting. These films exhibited good mechanical properties, with tensile strengths of 91–108 MPa, elongations to break of 6–17%, and initial moduli of 1.95–2.43 GPa. These polyamides showed glass‐transition temperatures between 193 and 252 °C. Most of the polymers did not show significant weight loss before 450 °C, as revealed by thermogravimetric analysis in nitrogen or in air. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4056–4062, 2004     

4-正戊酰基三联苯的合成

以三联苯和正戊酰氯为原料,经Friedel-Crafts反应合成了4-正戊酰三联苯(2)。考察了反应温度、溶剂用量和反应时间对2收率的影响。最佳的反应条件为:三联苯100 mmol,反应温度10℃,溶剂二氯乙烷600mL,反应时间30 min。在此最佳反应条件下,2的收率为89%,纯度达90%(GC)。     

Rigid‐rod polyamides and polyimides prepared from 4,3″‐diamino‐2′,6′‐di(2‐naphthyl)‐p‐terphenyl and 2′,6′,3‴,5‴‐tetra(2‐naphthyl)‐4,4″‐diamino‐p‐quinquephenyl

A series of rigid‐rod polyamides and polyimides containing p‐terphenyl or p‐quinquephenyl moieties in backbone as well as naphthyl pendent groups were synthesized from two new aromatic diamines. The polymers were characterized by inherent viscosity, elemental analysis, FT‐IR, ¹H‐NMR, ¹³C‐NMR, X‐ray, differential scanning calorimetry (DSC), thermomechanical analysis (TMA), thermal gravimetric analysis (TGA), isothermal gravimetric analysis, and moisture absorption. All polymers were amorphous and displayed T_g values at 304–337°C. Polyamides dissolved upon heating in polar aprotic solvents containing LiCl as well as CCl₃COOH, whereas polyimides were partially soluble in these solvents. No weight loss was observed up to 377–422°C in N₂ and 355–397°C in air. The anaerobic char yields were 57–69% at 800°C. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 15–24, 1999     

Synthesis,Structure and Nickel Carbonyl Complexes of Dialkylterphenyl Phosphines

The experimental and computational characterization of a series of dialkylterphenyl phosphines, PR₂Ar′ is described. The new P-donors comprise five compounds of general formula PR₂Ar (R=Me, Et, iPr, c-C₅H₉ and c-C₆H₁₁); Ar = 2,6-C₆H₃-(3,5-C₆H₃-(CMe₃)₂)₂), and another five PR₂Ar′ phosphines containing the bulky alkyl groups iPr, c-C₅H₉ or c-C₆H₁₁, in combination with Ar′=Ar , Ar , or Ar ( L1 – L10 ). Steric and electronic parameters have been determined computationally and from IR and X-ray data obtained for the phosphines and for some derivatives, including tricarbonyl and dicarbonyl nickel complexes, Ni(CO)₃(PR₂Ar′) and Ni(CO)₂(PR₂Ar′). In the solid state, the free phosphines PR₂Ar′ adopt one of the three possible structures formally related by rotation around the C_ipso−P bond. Details on their relative energies and on the influence of the free phosphine structure on its coordination chemistry towards Ni(CO)_n (n = 2, 3) fragments has been obtained by experimental and computational methods.     

Poly(aryl ether)s containing o‐terphenyl subunits. III. Random copoly(ether imide)s

The synthesis of a new diamine monomer, N‐n‐butyl 3,12‐diamino‐5,6,9,10‐tetrahydro[5]helicene‐7,8‐dicarboxylic imide (4), that contains a helically locked, U‐shaped 4′,4″‐o‐terphenyl moiety is described. The monomer was polymerized with 3,3′,4,4′‐oxydiphthalic dianhydride and 2,2‐bis[4‐(4‐aminophenoxy)phenyl]propane to form a series of copoly(ether imide)s (5a–e). The incorporation of 4 into the poly(ether imide)s varied the glass‐transition temperature of the copolymers of which it was a part. There was a tendency to form macrocyclic materials at higher molar percentages of 4 during polymerization. The fluorescence of all the copoly(ether imide)s gradually decreased as the content derived from monomer 4 increased in the polymer. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 758–763, 2000     

On the influence of the chiral side linking bridge type upon the synclinic vs. anticlinic balance in the case of 2′,3′-difluoroterphenyl derivatives

A homologous series of new ferro- and antiferroelectric liquid crystals, containing 2′,3′-difluorosubstituted terphenyl core as a mesogenic core, has been recently synthesised. Synthetic routes and mesomorphic properties were described. Liquid crystal phases were preliminarily determined by thermomicroscopic and microcalorimetric measurements and verified by dielectric measurements and miscibility methods. Temperatures and enthalpies of phase transitions are given.     

Chemoselective one‐pot synthesis of terphenyl derivatives by sequential directed C―H functionalization–Suzuki coupling

A simple and efficient route for the preparation of terphenyl derivatives via palladium‐catalyzed sequential directed C―H arylation/Suzuki–Miyaura cross‐coupling in ‘one‐pot’ has been developed. 4,4′‐(Cyclohexane‐1,1‐diyl)diphenol is an essential ligand. This reaction can tolerate a series of functional groups and provides the terphenyl derivatives in moderate to good yield. Copyright © 2014 John Wiley & Sons, Ltd.     

Electronic absorption and emission spectral data and fluorescence quantum yields of bridgedp-oligophenylenes,bi- to deciphenyls,and related furans and carbazoles

Absorption and fluorescence emission spectral data, as well as fluorescence quantum yields (_f), were determined for 41p-oligophenylene compounds containing 2–6, 8, and 10 benzene rings. Of 29 compounds containing carbon-bridged rings (fluorenes), 28 were dialkylated on each bridge for improved solubility and photostability. Absorption maxima for oligophenylenes were observed at wavelengths as long as 366 nm, emission maxima to 437 nm, and molar extinction coefficients () as large as 153,000 L/mol-cm; all three exceeded predicted maximum values for the corresponding unbridged oligophenylenes. The substitution of furan for benzene or carbazole for a fluorene (two examples each) bathochromically shifted absorption and emission maxima. Dialkylated carbon bridges bathochromically shifted absorption and emission maxima, and lowered _f in biphenyl and in one terphenyl analogue, but appeared to cause no diminution of _f in higher oligophenylenes. Bis(2-methoxyethyl) substitution on the bridges, incorporated to provide solubility in polar solvents, lowered _f in all examples. Tertiary alkyl substituents on terminal rings bathochromically shifted the absorption and emission maxima and generally increased _f. The loose bolt effect, which lowers _f in mononuclear substituted benzenes, may operate in 9,9-dialkylfluorenes, but not in 2,7-di-t-butylfluorene or in higher oligophenylenes. Cyclic ether and methoxy substituents as auxofluors on terminal rings generally bathochromically shifted absorption and emission maxima and increased and _f. Cyano substituents bathochromically shifted absorption and emission maxima, and increased , but lowered _f slightly.     

A Convenient Synthesis of Triquinacene

We have recently reported the synthesis of a derivative of triquinacene (2,3-dihydrotriquinacen-2-one (14)⁴) from Thiele's acid (1). Although this new synthetic route is simple in concept, it suffers from a large number of chemical steps. We wish to communicate an important overall simplification of this synthetic scheme which makes readily available triquinacene (22) and several of its derivatives.