Mohamed A. Abd-Alla

Arylidene Polymers. IX. Synthesis, Characterization, and Morphology of New Polyesters of Diarylidenecycloalkanones Containing Thianthrene Units

Abstract New polyesters containing thianthrene tetraoxide were synthesized by the interaction of 2,7-dichloroformylthianthrene-5,5′,10, 10′-tetraoxide with 2,5-bis(p-hydroxybenzylidene)cyclopentanone, 2,5-divanillylidenecyclopentanone, 2,6-bis(p-hydroxybenzyiidene)-cyclohexanone, 2,6-divanillylidenecyclohexanone, and 2,7-bis(p-hydroxybenzylidene)cycloheptanone by using the interfacial polycondensation technique. The resulting polyesters were characterized by elemental and spectral analyses. All the synthesized polymers readily dissolved at room temperature in dimethylsulfoxide. The thermal properties of the polymers were evaluated and correlated to their structural units by TGA and DSC measurements. X-ray analysis of polymers showed that all the polyesters are amorphous. Moreover, the morphology of a new high performance polyester, poly[oxycarbonyl-2,7-thianthrene-5,5′,10,10′-tetraox-idecarbonzeoxyl(2-methoxy-p-phenylene)methylidyne(2-oxo-1,3-cyclohexanediylidenemethylidyne)methylidene(3-methoxy-p-phenyle...

Arylidene Polymers. Ii. Synthesis and Characterization of Some New Polyesters of Diarylidenecyclopentanone

Abstract New polyesters formed by interfacial polycondensation of 2,5-bis(4-hydrox-ybenzylidene)cyclopentanone (I) and 2,5-bis(4-hydroxy-3-methoxybenzyli-dene)cyclopentanone (II) with 4,47prime;-diphenic, isophthaloyl, terephthaloyl, adi-poyl, suberoyl, and sebacoyl dichlorides were obtained. The yield and the values of the reduced viscosity of the produced polyesters were found to be affected by the type of organic phase, the quantitative ratio of organic to aqueous phase, the concentration of the hydrogen chloride acceptor, and the contribution of benzyltriethylammonium chloride as a catalyst. In order to characterize these polymers, the necessary model compounds were prepared from I, II, and benzoyl chloride. The resulting polyesters were confirmed by IR, elemental analysis, viscometry, DTA, DSC measurements, and thermogravi-metric analysis. The crystallinities of all polyesters were examined by x-ray analysis, and the electrical properties of the polyesters were tested.

Arylidene Polymers VII. Synthesis and Characterization of New Polyesters of Diarylidenecycloalkanones Containing an Azo Group in the Main Chain

A new interesting class of linear, unsaturated polyesters based on diarylidenecycloalkanones containing an azo linkage in the polymer main chain have been synthesized by interfacial polycondensation of 4,4′-azodibenzoyl chloride or 3,3′-azodibenzoyl chloride with 2,5-bis(p-hydroxybenzylidene)cyclopentanone, 2,5-divanillylidenecyclopentanone, 2,6-bis(p-hydroxybenzylidene)cyclohexanone and 2,6-divanillylidenecyclohexanone at ambient temperature. The resulting polyesters were characterized by elemental analyses, IR spectroscopy, solubility and viscometry measurements. The thermal properties of the polymers were evaluated by TGA and DSC measurements and correlated to their structural units. X-ray analysis of the polymers showed that polyesters based on the meta azo linkage were totally amorphous whereas, polyesters with the para azo linkage had some degree of crystallinity. The UV-visible spectra of certain polymers were measured in m-cresol solution and showed a characteristic absorption band at 438-465 nm due to n-π* transition. In addition, the electrical properties of all polyesters were measured.

New coordination polymers. Part 1.—Novel synthesis of poly(vinyl ketone) and characterization as chelating agent

Poly(vinyl ketone)(PVK) has been prepared by the oxidation of poly(vinyl alcohol)(PVA) with potassium permanganate in alkaline media (pH > 12) with a yield of 98.6%. The chemical structure of the synthesized macromolecule (PVK) has been elucidated by IR spectroscopy and microanalysis. Sol–gel transformation and or precipitation processes were observed when PVK was added to polyvalent metal ion electrolytes A mechanism for chelation consistent with the experimental results is suggested.

New coordination polymers. Part 2.—Coordination of poly(vinyl ketone) with divalent metal ions

Coordination polymers of poly(vinyl ketone)(PVK) have been prepared with the metal ions Cu2+, Ni2+, Co2+, Cd2+ and Hg2+. They have been characterized by elemental analysis, IR spectroscopy, electronic spectroscopy and conductivity measurements. The metal contents in all polymers were found to be consistent with a 1:2 (metal: PVK ligand) stoichiometry. It was found that PVK behaves as a monobasic bidentate similar to that of poly(β-diketone). The bonding sites were ascertained, and the CuII, NiII, CoII, CdII and HgII polymeric complexes were formulated to assume tetrahedral geometry. The thermal behaviour of these coordination polymers was studied by thermogravimetric analysis in air, and the data showed that they are thermally stable up to 360 °C.

Synthesis and characterization of high-spin iron(III)-sulpha drug complexes and their biological activity

SummaryThe iron(III) complexes with sulphathiazole, sulphamethoxazole, sulphadiazine, sulphapyridine and sulphadimidine having the stoichiometric ratio 1:2 (metal:ligand) were prepared and characterized on the basis of elemental analysis, conductivity measurements and electronic absorption spectra. The infrared spectra of the complexes revealed that the terminal amino group of the sulpha molecules is not involved in coordination. Similarities in the position of iron-nitrogen and iron-oxygen stretching modes indicate identical configuration of the complexes prepared. Conductivity measurements showed that they are nonelectrolytes. X-ray powder diffraction patterns showed that two of them are crystalline and others are amorphous. Electron spin resonance and iron-57 Mössbauer measurements indicated that the complexes contain high-spin Fe3+ species. Thermogravimetric analyses showed that all complexes contain coordinated water which is lost at 141–160°C. All the complexes proved to possess higher bacteriostatic activity than the corresponding ligand.ZusammenfassungEs wurden die (Metall:Ligand) 1:2 Eisen(III)-Komplexe von Sulfathiazol, Sulfamethoxazol, Sulfapyridin und Sulfadimidin hergestellt und mittels Elementaranalyse, Leitfähigkeitsmessungen und Elektronenabsorptionsspektroskopie charakterisiert. Die IR-Spektren der Komplexe zeigten, daß die Amino-Gruppen der Sulfa-Moleküle nicht an der Koordination beteiligt sind. Ähnlichkeiten im Bereich der Eisen-Stickstoff- und Eisen-Sauerstoff-Streckschwingungen zeigten idente Konfiguration der Komplexe an. Leitfähigkeitsmessungen beweisen den Nichtelektrolytcharakter. Röntgen-Pulverdiagramme zeigten, daß zwei der Komplexe kristallin, die anderen hingegen amorph waren. High-Spin Eisen(III)-Spezies wurden mittels Elektrononspinresonanz und Eisen-57-Mössbauer-Messungen nachgewiesen. Die thermogravimetrische Analyse zeigte, daß alle Komplexe koordiniertes Wasser enthielten, das zwischen 141 und 160°C verloren wurde. Alle Komplexe zeigten eine höhere bakteriostatische Aktivität als die entsprechenden Liganden allein.

Arylidene polymers: 15. Optical band gap and structural relationship of new polyester films of dibenzylidenecyclohexanone

Abstract The optical properties of poly[oxyisophthaloyloxy-(2-methoxy-p-phenylene methylidene-(2-oxo-1,3-cyclohexanediylidene) methylidyne-(3-methoxy-p-phenylene)] (I) and poly[oxysebacoyloxy-(2-methoxy-p-phenylene)methylidene-(2-oxo-1, 3-cyclohexanediylidene)methylidene-(3-methoxy-p-phenylene)] (II) polymer films were studied. The transmission and absorption measurements were carried out in the energy range 1.9–3.2 eV at 300 K. The data on absorption coefficient versus photon energy were analysed and interpreted in terms of the Tauc model, (α h ω) 1 2 = B 1 2 ( h ω − E opt g ) . Analysis of experimental results shows that the absorption characteristics give a good fit to the Tauc model, and indicates that both polymers I and II have an indirect band gap. The values of the optical gap Eoptg and the slope of the Tauc plots B 1 2 were determined. The study shows that the indirect allowed optical transitions are the predominant transitions in the optical absorption process. From the data a correlation between optical band gap and polymer structure was observed and discussed.

Arylidene Polymers VIII. Synthesis, Characterization and Morphology of New Polyesters Based on 2,7-Diarylidenecycloheptanone

New polyesters have been synthesized via interfacial polycondensation of 2,7-bis(p-hydroxybenzylidene)cycloheptanone I with 4,4′-diphenic, isophthaloyl, tere-phthaloyl, adipoyl and sebacoyl dichlorides at ambient temperature. In order to characterize these polyesters a model compound II was prepared from I and benzoyl chloride. The resulting polyesters were characterized by IR, 1H-NMR, elemental analyses, viscometry, solubility measurements, DSC and thermogravimetric analyses. The crystallinity of the polymers was examined by X-ray analysis. The morphology of a high performance polyester namely poly[oxyisophthaloxy-p-phenylenemethylidyne (2-oxy-l,3-cycloheptanediylidene)methylidyne-p-phenylene] has been investigated by scanning and transmission electron microscopy.

Arylidene Polymers XIII—Synthesis, Characterization and Morphology of New Unsaturated Polycarbonates via Phosgenation of Diarylidenecycloalkanones

A new interesting class of linear unsaturated polycarbonates based on 2,5-bis(p-hydroxybenzylidene) cyclopentanone I, 2,5-divanillylidenecyclopentanone II, 2,6-bis(p-hydroxybenzylidene) cyclohexanone III, 2,6-divanillylidenecyclohexanone IV and 2,7-bis(p-hydroxybenzylidene) cycloheptanone V have been prepared. An inter-facial phosgenation technique carried out at ambient temperature was used for the synthesis of the polycarbonates. The resulting polycarbonates were characterized by elemental analyses, infrared spectroscopy, 1H nuclear magnetic resonance spectral analyses, viscometry, differential scanning calorimetry and thermogravimetric analysis measurements. The majority of the polycarbonates were soluble in halogenated solvents. The crystallinity of all the polymers was examined by X-ray analysis. In addition, the electrical properties of the polycarbonates were tested. Furthermore, the morphology of selected examples of the polycarbonates was examined by scanning electron microscopy.

Arylidene polymers: 11. Synthesis of poly[2,5-bis(m-nitrobenzylidene)-cyclopentanone sulphide] and some theoretical studies on its monomer unit

Abstract Nitration of 2,5-bis( p -chlorobenzylidene)cyclopentanone (I) afforded the corresponding 2,5-bis( p -chloro- m -nitrobenzylidene)cyclopentanone (II). Polymerization of II with Na 2 S in N -methylpyrrolidone gave poly[2,5-bis(3-nitrobenzylidene)cyclopentanone sulphide]. The monomer was characterized by infra-red and 1 H nuclear magnetic resonance spectroscopy and elemental analysis. The polymer formed was confirmed by elemental analysis, infra-red spectroscopy, viscometry, differential thermal analysis measurements, thermogravimetry and X-ray analysis. An isothermal electrical conductivity test of the new polysulphide polymer indicates that it has a value of about 3.2 × 10 −3 ohm −1 cm −1 at 390 K. Using the Pariser-Parr-Pople method the CO oxygen atom in compound II has a partially positive charge in the normal state, reduced and oxidized forms. The ionization potential and the electron affinity are not altered by replacing the sulphur atom, i.e. 9.55 (9.56) and 7.94 (7.77).