Materials Literature
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A convenient procedure for the synthesis of porphyrin derivative dyads is described. The dyads consist of a free base porphyrin covalently linked to a zinc porphyrin or ferrocene by an amide bond. 5-(4-Substituted phenyl)-10,15,20-tris(4-methylphenyl) porphyrins were synthesized from meso-(4-methylphenyl) dipyrrometha…
The HF/6-31G* level of theory was used to calculate relaxed potential energy surfaces for 12 analogs of disaccharides. The analogs were made by replacing glucose with tetrahydropyran and fructose with 2-methyltetrahydrofuran. Molecules had zero, one or two anomeric carbon atoms, and di-axial, axial-equatorial, and di-…
Hydroxy phenyl-substituted cyclotriphosphazenes were synthesized by reacting hexachlorocyclotriphosphazene with sodium phenolate and monosodium bisphenolate. The derivatives, consisting of a mixture of multi-substituted and partly chain-extended cyclophosphazenes, with overall functionality close to the targeted value…
Ionic species can be stabilized in the water core of a water-in-CO2 microemulsion in supercritical fluid CO2; by mixing two microemulsions containing Ag+ and X− ions separately, silver halide (AgX) nanoparticles were synthesized in supercritical CO2; the water-in-CO2 microemulsion may provide a reaction system for a w…
Solubilities of diuron in 19 organic solvents are reported. These are combined with the solubility in water and the vapour pressure of diuron to give 19 values of water–solvent partitions, P, and 19 values of gas–solvent partitions, L. Coefficients in the general solvation equations i and ii are known for all 38 of th…
Poly(tetrafluoroethylene) (PTFE) films with surface grafted poly(ethylene glycol) (PEG) chains were prepared by two methods: (1) UV-induced graft copolymerization of methoxy poly- (ethylene glycol) monomethacrylate (PEGMA) onto the plasma-pretreated PTFE films; and (2) coupling of the hydroxyl groups of PEG via ester…
After isothermal crystallization, poly(ethylene terephthalate) (PET) showed double endothermic behavior in the differential scanning calorimetry (DSC) heating scan. During the heating scans of semicrystalline PET, a metastable melt which comes from melting thinner lamellar crystal populations formed between the low an…
Three studies are reported here: (i) dilatometric experiments on pressure amorphization of polycrystalline hexagonal ice (ice Ih) of different grain-size; (ii) interpretation of the stability of water-B against its transformation to water-A (Johari et al., Science, 1996, 273, 90) in terms of the time required for the…
Molybdenum cofactor (Moco) biosynthesis is an evolutionarily conserved pathway in archaea, eubacteria, and eukaryotes, including humans. Genetic deficiencies of enzymes involved in this biosynthetic pathway trigger an autosomal recessive disease with severe neurological symptoms, which usually leads to death in early…
Polyester matrix composites reinforced using nonwoven coir or oil palm empty fruit bunch fiber mats were manufactured. Fibers were used unmodified, chemically modified by acetylation, or treated with silane or titanate coupling agents. Composite test pieces were exposed to decay fungi in unsterile soil for up to 12 mo…
Manganese-exchanged Al-MCM-41 modified by the chiral salen ligand [(R,R)-(−)-N,N′-bis(3,5-di-tert-butylsalicylidene)cyclohexane-1,2-diamine] can be used as an enantioselective heterogeneous epoxidation catalyst using iodosyl benzene as oxygen donor. Epoxidation of (Z)- and (E)-stilbene is studied in detail and experim…
This article describes the solution behavior of model amphiphilic linear-dendritic ABA block copolymers that self-assemble in aqueous media and form micelles with highly branched nanoporous cores. The materials investigated are constructed of poly(ethylene glycol), PEG, with molecular weight 5,000 or 11,000 as the wat…
The absorption and CD spectra of a series of Fréchet (compounds 7-10) and backfolding (compounds 11-12) dendrimers derived from enantiopure (S)-2,2′-dihydroxy-1,1′-binaphthalene have been recorded (THF) in the range 200-350 nm. All the compounds examined show a positive couplet between 200 and 240 nm (1B transition of…
The luminescence emission of a new dipyridyl-containing Eu(III) cryptate complex is modulated by pH, due to protonation of the polyamine chain strategically inserted within the ligand backbone.
It is now well known that the addition and trimming of oligosaccharide side chains during post-translational modification play an important role in determining the fate of secretory, membrane, and lysosomal glycoproteins. Recent studies have suggested that trimming of oligosaccharide side chains also plays a role in t…
Overview of IC Interconnects. Behavior of Copper Impurity Atoms. Copper-Related Defects in Silicon. Chemistry and Electrochemistry. Copper in Inorganic Dielectrics. Copper in Organic Dielectrics (Polymers). Diffusion and Compound Formation. Layered Structures Containing Copper. Copper for IC Metallization. Future Dire…
The heptadentate ligand 2POAP combines two bridging alkoxide oxygen donors with diazine and pyridine terminal nitrogen donors in a linear array with the binding sites positioned critically to accommodate three metal centres, but on reaction with Mn(ClO4)2·6H2O a strict self assembly process occurs, producing a unique…
The co-ordination properties toward Na+, Ca2+, Zn2+, Cu2+ and Gd3+ of six ligands containing pendant functionalities attached to the common 1,4,7,10-tetraazacyclododecane macrocyclic ring have been studied by means of potentiometric and microcalorimetric methods. Stability constants for the 1,4,7,10-tetra(methylcarbam…
Dianionic members of the Mn12 family of single-molecule magnets have been prepared by two-electron reduction of the neutral cluster; the [PPh4]2[Mn12O12(O2C CHCl2)16- (H2O)4] representative has been shown to possess an S = 10 ground state and to exhibit out-of-phase ac susceptibility signals diagnostic of single-molec…
A series of titania modified mesoporous silicate MCM-41 (MCM-TiO2) samples with variable Ti/Si ratios have been synthesized from tetrabutyltitanate and calcined MCM-41. The samples were characterized by powder X-ray diffraction (XRD), FTIR spectroscopy, thermal analysis (DTA–TG), nitrogen adsorption–desorption at 77 K…