University of Windsor

About: University of Windsor is a education organization based out in Windsor, Ontario, Canada. It is known for research contribution in the topics: Population & Argumentation theory. The organization has 10654 authors who have published 22307 publications receiving 435906 citations. The organization is also known as: UWindsor & Assumption University of Windsor.

Unexpected intermediates and products in the C-F bond activation of tetrafluorobenzenes with a bis(triethylphosphine)nickel synthon: direct evidence of a rapid and reversible C-H bond activation by Ni(0).

Abstract: The reaction of (PEt(3))(2)Ni(eta(2)-C(14)H(10)), a source of the reactive Ni(PEt(3))(2) moiety, with 1,2,4,5-F(4)C(6)H(2) yields a mixture of three C-F bond activation products that include the unexpected products (PEt(3))(2)NiF-2,3,5,6-F(4)C(6)H and (PEt(3))(2)NiF-2,3,5-F(3)C(6)H(2). Monitoring the reaction mixture via (19)F and (1)H NMR also reveals the presence of the C-H bond activation product, (PEt(3))(2)NiH-2,3,5,6-F(4)C(6)H which is produced in a rapid equilibrium reaction. This observation provides insight into the steps necessary to modify nickel complexes for selective C-F bond activation in a variety of polyfluorinated aromatic substrates, but also expands the potential of simple nickel compounds for C-H bond activation and functionalization reactions.

Diagenesis and reservoir-quality evolution of fluvial sandstones during progressive burial and uplift: Evidence from the Upper Jurassic Boipeba Member, Reconcavo basin, northeastern Brazil

Abstract: The reservoir quality of fluvial sandstones of the Upper Jurassic Boipeba Member, Reconcavo basin, northeastern Brazil, is highly heterogeneous and controlled by eodiagenesis under semiarid climate, mesodiagenesis during burial to a depth of 3500 m, and telodiagenesis due to local uplift. Eodiagenesis resulted in mechanical compaction, calcite cementation, clay infiltration, and limited grain dissolution, whereas mesodiagenesis resulted in the precipitation of calcite cement and quartz over growths, intergranular quartz-grain dissolution, chloritization and illitization of smectite, and albitization of feldspars. Sandstones continuously buried at maximum burial depths of about 1600 m (T = 65°C) since 125 Ma display a relatively greater degree of mesogenetic modifications and, on average, poorer reservoir quality than sandstones that were buried deeper (2100 m, T = 75°C) prior to uplift, but only since 13 Ma. Uplift, which affected the sequence along the western border of the basin, has resulted in telogenetic dissolution of framework silicates and formation of kaolinite. Relatively good reservoir quality in the deeply buried sandstones occurs when (1) the grains are coated with a thin layer of chloritized infiltrated smectite, (2) there is little or no pseudomatrix, and (3) there are widely scattered patches of eogenetic calcite cement that supported the framework of sandstones against compaction.

Langmuir and Langmuir−Blodgett Films of Perylene Tetracarboxylic Derivatives with Varying Alkyl Chain Length: Film Packing and Surface-Enhanced Fluorescence Studies

Abstract: The synthesis, film-packing properties in Langmuir and Langmuir−Blodgett (LB) films, and surface-enhanced fluorescence (SEF) of a new family of perylene tetracarboxylic derivatives (PTCD) are reported. The molecular organization on water subphase is extracted from surface pressure−area (π−A) isotherms recorded under varying compression speeds and subphase temperatures. It was found that the π−A isotherms are temperature dependent and the area per molecule decreases with increasing temperature of the subphase. The effect is more pronounced for molecules with longer lateral chains. The isotherm for these molecules can reach high pressures, indicating strong packing on the water surface. The presence of hysteresis with and without collapsing of the film indicates the formation of aggregates on the water surface. Further, the shift to smaller areas per molecule for successive compressions shows that the aggregates are stable. The π−A isotherms were found to be independent of the compression speed. The area va...