Search results for "Isophthalic acid"
showing 5 items of 5 documents
Synthesis and X-ray structure of amide-based macrocycles, catenanes and pretzelane
2001
The syntheses and crystal structure studies of amide-based catenanes derived from m-phenylene diacrylic acid and 5-acetoxy isophthalic acid (17% and 3% yield of 4a and 4b resp.) and octalactam macrocycles (21% yield of 3) are described. Hydrogen bonding patterns play a key role in the formation of the different conformations of octalactam 3. The crystal structures of 3 reveal a number of hydrogen-bonding interactions between the macrocycle and two different solvent molecules, which are presumably responsible for the different conformations. Furthermore, we report the X-ray structure of a catenane, which was converted into a “pretzelane” by bridging two phenolic hydroxy groups with a p-xylyl…
Effect of modulator connectivity on promoting defectivity in titanium–organic frameworks
2020
The recognition of defect chemistry as a true synthetic tool for targeted creation of defects and controllable performance remains limited by the pool of frameworks explored. The value of defect engineering in controlling the properties of defective frameworks has been beautifully exemplified and largely demonstrated with UiO-type materials based on Zr(iv) nodes. However, titanium–organic frameworks remain largely unexplored in this context arguably due to the complex chemistry in solution of Ti(iv) and the difficulties in growing crystalline solids. We report a systematic study on the ability of mono- and dicarboxylic modulators (benzoic and isophthalic acid) to promote defect creation in …
Oligo(phenylenevinylene)s with increased electron affinity: 1,3,4-oxadiazoles in the main chain
2001
Stilbenoid chromophores and 2,5-diaryl-1,3,4-oxadiazoles are compounds with wide technical importance. Their intense fluorescence is used in szintillators and optical whiteners and their semiconducting properties makes them valuable emissive or electron conducting layers in organic light emitting diodes (OLED). The synthesis and the electronic spectra of soluble oligo(phenylenevinylene)s with 1,3,4-oxadiazoles in the main chain are presented. The Huisgen reaction of tetrazole-terminated stilbenoid compounds with aromatic acyl chlorides yields model compounds, isophthalic acid dichlorides lead to soluble polymers with well-defined conjugated segments, as can be seen in the electronic spectra…
Aromatic dicarboxylate incorporated new di- and tetranuclear cobalt(II) complexes: Synthetic and structural aspects, and evaluation of properties and…
2020
Abstract The synthetic and structural aspects as well as evaluation of magnetic properties and catalytic activity toward aerial oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylbenzoquinone of three new, two di- and one tetranuclear cobalt(II) complexes, [Co2(cpdp)(Hphth)]∙5H2O (1), [Co2(cpdp)(Hisophth)] (2) and [Co4(cpdp)2(terephth)]∙4.5CH3OH·5.5H2O (3), based on a symmetrical multidentate ligand, N,N'-Bis[2-carboxybenzomethyl]-N,N'-Bis[2-pyridylmethyl]-1,3-diaminopropan-2-ol (H3cpdp) in combination with exogeneous aromatic dicarboxylic acids, such as phthalic acid (H2phth), isophthalic acid (H2isophth) and terephthalic acid (H2terephth) are reported. All three coordination compl…
Synthesis and Characterization of a New Class of Fully Aromatic Liquid Crystal Polymers
1999
Abstract A new fully aromatic LCP, obtained by polycondensation of N-(4-carboxyphenyl) trimellitimide and tert-butyl hydroquinone (FAPT), was previously described. The polymer shows very interesting physical and mechanical properties but a very high glass transition temperature which does not allow a good processability. In order to overcome this problem, a new class of LCPs, obtained by partial substitution of the dicarboxylic moiety with isophthalic acid, is described. The new thermoplastic materials were characterized from the physicochemical and mechanical point of view. All the polymers obtained with an isophthalic acid (FA-IA) content varying from 10 to 40% of the substituted moiety s…