Crucial model synthetic and mechanistic studies directed toward the development of methodology for the construction of the maleic anhydride moiety of the CP-molecules are described. Studies directed toward the stereoselective attachment of the upper side chain, culminating in the discovery of long-range stereochemical control, are also discussed. In addition, a first-generation strategy toward ...

In the crystal structure of the title 1:1 adduct, C(12)H(8)N(2)·C(14)H(6)O(7), the carboxyl groups are involved in inter-molecular O-H⋯O hydrogen bonds, which link the mol-ecules into centrosymmetric dimers. These dimers are further linked by inter-molecular O-H⋯N hydrogen bonds. C-H⋯O inter-actions also occur between the 1,10-phenanthroline (phen) and 4,5-dicarb-oxy-naphthalene-1,8-dicarb-oxy-...

In recent years, the interest for bio-sources is rising exponentially and tannins extracts are one of the most interesting, easily-available, phenolic building blocks. The condensed tannins or proanthocyanidins are already known for their polymerization chemistry, which is the basis for several natural-based materials (e.g., adhesives, foams). In the present work we aim to observe the behavior ...

Modification of Styrene-maleic anhydride copolymer, synthesized in toluene using benzoyl peroxide (BPO) as initiator, through graft copolymerization of hydrophilic monomer, acrylic acid, (AAc), has been carried out in aqueous medium by chemical and gamma radiation methods. Optimum conditions pertaining to maximum percentage of grafting were evaluated as a function of different reaction paramete...

Three Bi-doped vanadyl pyrophosphate catalysts were prepared via dihydrate route (VPD method), which consisted of different preparation methods including mechanosynthesis, mechanochemical treatment, and the conventional reflux method. The catalysts produced by the above three methods were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and temperature programmed re...

Modification of yeast ribosomes with dimethylmaleic anhydride, a reagent for protein amino groups, is accompanied by loss of polypeptide-synthesizing activity. This activity can be recovered by incubation at pH 6, which produces regeneration of the modified amino groups. Dimethylmaleic anhydride modification also causes the dissociation of proteins from the ribosomes. Protein-deficient ribosoma...

Introduction In 1950, the chemists Otto Paul Hermann Diels, from Germany, and Kurt Alder, originally born in Prussia and then moved to Germany after World War I, received the Nobel Prize in chemistry for the discovery of a new way to synthesize cyclic molecules. Aptly titled the Diels-Alder Cycloaddition Reaction, this new mechanism allowed conjugated dienes to undergo addition reactions with a...

Boric acid-pyridine mixture is presented as mild catalyst for polycondensation of semi-esters of ethylene glycol, in situ-generated by “cyclic anhydrideediol” reaction scheme from maleic, succinic and phthalic anhydrides. This catalyst system was demonstrated to give colorless polyesters in low molecular weights (Mn: 1650e1950 Da) within 4 h at 130 C 1H NMR spectra of the polyesters derived fro...

Iron oxide nanoparticles (NPs) with diameters of 16.1, 20.5, and 20.8 nm prepared from iron oleate precursors were coated with poly(maleic acid-alt-1-octadecene) (PMAcOD). The coating procedure exploited hydrophobic interactions of octadecene and oleic acid tails while hydrolysis of maleic anhydride moieties allowed the NP hydrophilicity. The PMAcOD nanostructure in water and the PMAcOD-coated ...

Jute fiber/polyethylene biocomposites were prepared using a hot press molding technique. The effects of maleic anhydride, clay, and silica on the physical, mechanical, and thermal properties of jute fiber-reinforced polyethylene (PE) biocomposites with different fiber loadings (5, 10, 15, and 20 wt.%) were investigated. The biocomposites were characterized by Fourier transform infrared spectros...