Mesogenic Properties of Aromatic Oligoesters Derived from Kink-Structured Monomers

Novel liquid crystalline oligomers were prepared using different compositions of kink-structured aromatic dicarboxylic acids, aromatic diols, and 4-hydroxybenzoic acid via high-temperature polycondensation. The reaction products were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and polarized optical microscopy. As a result, the samples containing kinked units with phenyl or naphthalene moiety had a broad processing window limited by the melting process and the isotropization, whereas one based on diphenic acid was almost entirely in an amorphous state. The surface properties of the oligomers were evaluated by wetting measurements using a static contact angle analysis.

Direct Synthesis of Polyaromatic Cyclophanes Containing Bis-Methylene-Interrupted Z-Double Bonds and Study of Their Antitumor Activity In Vitro

An original synthetic route was developed for the preparation of previously unknown unsaturated polyaromatic macrolactones containing a 1Z,5Z-diene moiety in 48–71% yields and with >98% stereoselectivity. The method is based on intermolecular cyclocondensation of aromatic dicarboxylic acids with α,ω-alka-nZ,(n+4)Z-dienediols (1,12-dodeca-4Z,8Z-dienediol, 1,14-tetradeca-5Z,9Z-dienediol, 1,18-octadeca-7Z,11Z-dienediol) mediated by N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC)/4-dimethylaminopyridine (DMAP). The unsaturated diols were prepared by successive homo-cyclomagnesiation of tetrahydropyran ethers of O-containing 1,2-dienes with EtMgBr in the presence of Mg metal and the Cp2TiCl2 catalyst (10 mol.%) and subsequent treatment with 0.1 equiv. of para-toluenesulfonic acid of pyran ethers formed after the acid hydrolysis of magnesacyclopentanes. The resulting cyclophanes exhibited high cytotoxic activity in vitro against Jurkat, K562, U937, and HL60 cancer lines. Additionally, the synthesized products were studied for their effect on mitochondria, ability to induce apoptosis, and influence on the cell cycle using modern flow cytometry methods.

Screening and characterization of a novel reversible 4-hydroxyisophthalic acid decarboxylase from Cystobasidium slooffiae HTK3

Owing to carboxylation activity, reversible decarboxylases can use CO2 as a C1-building block to produce useful carboxylic acids. Although many reversible decarboxylases can synthesize aromatic monocarboxylic acids, only a few reversible decarboxylases have been reported to date that catalyze the synthesis of aromatic dicarboxylic acids. In the present study, a reversible 4-hydroxyisophthalic acid decarboxylase was identified in Cystobasidium slooffiae HTK3. Furthermore, recombinant 4-hydroxyisophthalic acid decarboxylase was prepared, characterized, and used for 4-hydroxyisophthalic acid production from 4-hydroxybenzoic acid.

Synthesis and characterization of new cardo poly(ether amide)s containing 9(10H)-anthrone units

A new aromatic diamine, 10,10-bis[4-(4-aminophenoxy)phenyl]-9(10 H)-anthrone (BAPA) has been synthesized from anthrone via three-step procedure. Direct phosphorylation polycondensation of BAPA with various aromatic dicarboxylic acids produced a series of cardo poly(ether amide)s with inherent viscosities of 0.97–1.29 dL g−1. All the polymers were readily soluble in polar solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide (DMAc), and pyridine at room temperature, and afforded transparent, strong, and flexible films upon casting from DMAc solvent. The resulting poly(ether amide)s had glass transition temperatures of 254–316°C, 10% weight loss temperatures of 495–524°C, and char yields of 55–70% at 800°C in nitrogen. These polymers were amorphous and their films exhibited tensile strengths of 81.6–104.7 MPa, tensile moduli of 1.8–2.4 GPa, and elongations at break of 8–15%.

Novel soluble and heat-resistant polyamides derived from 4-(4-diphenylphosphino) phenyl-2,6-bis(4-aminophenyl)pyridine and various aromatic dicarboxylic acids

New diamine, 4-(4-diphenylphosphino)phenyl-2,6-bis(4-aminophenyl)pyridine, was prepared, and the related polyamides (PAs) bearing 2,6-diphenylpyridyl units and pendant diphenylphosphinophenyl groups were synthesized by direct polycondensation of this diamine and various aromatic diacids in N-methyl-2-pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. The resulting PAs with inherent viscosities of 0.78–1.06 dL g−1 are readily soluble in polar aprotic solvents such as NMP, N, N-dimethylacetamide, and dimethylsulfoxide as well as less polar solvents such as m-cresol and pyridine. All the PAs are amorphous and could be solution-cast into transparent, flexible, and tough films, which have tensile strengths of 68.2–88.8 MPa, tensile moduli of 1.9–2.4 GPa, and elongations at break of 5.4–10.3%. These polymer films also exhibit high optical transparence with the UV cutoff wavelength in the 361–412 nm range. These PAs display glass transition temperatures of 316–332°C, 10% mass loss temperatures of 524–553°C, and more than 48% residues at 800°C in nitrogen, respectively. Their high char yields and good limited oxygen index values ranging from 39 to 44 indicate the prepared PAs show good thermal stability and flame-retardant property.

Binaphthyl-Based Macrocycles as Optical Sensors for Aromatic Diphenols

The synthesis of several rigid, homochiral organic macrocycles possessing, respectively, average molecular D2 and D3 symmetries, is described. They have been obtained from aromatic dicarboxylic acids, in combination with an axially-chiral, suitable dibenzylic alcohol, derived from 1,1′-binaphthyl-2,2′-diol (BINOL) using one-pot esterification reactions in good isolated yields. NMR and circular dichroism (CD) spectroscopies detect the structural and shape variability in the scaffolds, reflected both in terms of the changes in chemical shifts and the shape of selected proton resonances, and in terms of the variation of the CD signature related to the dihedral angle defined by the binaphthyl units embedded in the rigid cyclic skeleton. The D2 cyclic adducts are able to form stable complexes with aromatic diphenols, with binding strengths that are dependent on small variations in the spacing units, and therefore on the shapes of the internal cavities of the cyclic structures.

Monitoring the structure–reactivity relationship in epoxidized perilla and safflower oil thermosetting resins

The reactivity of epoxidized perilla oil and epoxidized safflower oil with two aromatic dicarboxylic acids was studied. The presence of S–S bonding at the β position of the carboxylic group increases the reactivity of the acidic proton toward epoxy ring opening.

Effects of two benzenedicarboxylic acids on the construction of CdII coordination polymers incorporating a flexible N-donor ligand

Compared with the monomorphic type of ligand, combining mixed ligands in one coordination polymer offers greater tunability of the structural framework. Employment of N-heterocyclic ligands and aromatic polycarboxylates is an effective approach for the construction of metal–organic frameworks (MOFs). Two new coordination polymers incorporating both 2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole (imb) and benzenedicarboxylic acid isomers, namely, catena-poly[[[di-μ-chlorido-bis[(2-carboxybenzoato-κ2 O 1,O 1′)cadmium(II)]]-bis{μ-2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole-κ2 N:N′}] dihydrate], {[Cd(C8H5O4)Cl(C11H10N4)]·H2O} n , (I), and poly[[aqua(μ2-benzene-1,3-dicarboxylato-κ3 O 1,O 1′:O 3){μ2-2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole-κ2 N:N′}cadmium(II)] dihydrate], {[Cd(C8H4O4)(C11H10N4)(H2O)]·2H2O} n , (II), have been prepared and structurally characterized by single-crystal X-ray diffraction. In polymer (I), imb ligands bridge CdII ions, forming a one-dimensional chain, and 2-carboxybenzoate anions coordinate to the CdII ions in a terminal fashion. Polymer (II) exhibits a two-dimensional network structure in which imb ligands and the benzene-1,3-dicarboxylate anions join CdII ions co-operatively. This indicates that changing of the aromatic dicarboxylic acids can result in polymers with different compositions and architectures. Moreover, their IR spectra, PXRD (powder X-ray diffraction) patterns, thermogravimetric analyses and fluorescence properties were also investigated.

Synthesis and properties of new 2,3,5,6-tetraaminopyridine based polyheteroarylenes

Two new polyheteroarylenes (polydiimidazopyridines) based on 2,3,5,6-tetraaminopyridine and aromatic dicarboxylic acids were synthesized and characterized. The polymers show high viscosity properties and exceptional thermooxidative stability. Polydiimidazopyridine containing a phosphoric acid group possesses excellent filmforming properties and can be processed to proton conducting membranes that have record high proton conductivity in the temperature range of 20-200 °C after doping with orthophosphoric acid.