Palladium-catalyzed reaction of aryl and alkenyl halides with terminal alkynes in the presence of silver(I) oxide as an activator furnishes various arylated or alkenylated alkynes in good to excellent yields. The similar coupling reaction is also found to proceed using tetrabutylammonium fluoride (TBAF) or tetrabutylammonium hydroxide (TBAOH) as an activator.

Palladium-catalyzed cross-coupling of aryl- or alkenylsilanols, silanediols, and silanetriols with a variety of iodoarenes by the catalysis of palladium(0) and in the presence of silver(I) oxide furnished the coupling products in good to excellent yields. The reactions of silanediols or silanetriols under similar conditions proceeded much faster than those of silanols to afford the corresponding coupling products in excellent yields within shorter reaction periods (5-12 h). The measurement of the X-ray diffraction (XRD) pattern of the silver residue after the reaction revealed that silver(I) oxide was converted to silver(I) iodide.

The reactions of aryl- and alkenylsilanols with organic halides are found to proceed in a catalyst system of 5 mol % of Pd(PPh3)4 and Ag2O (1 equiv) to give the corresponding coupling products in up to 84% yield.

The growth behavior of anodic porous alumina formed by anodizing in novel electrolyte solutions, the cyclic oxocarbon acids croconic and rhodizonic acid, was investigated for the first time. High-purity aluminum specimens were anodized in 0.1 M croconic and rhodizonic acid solutions at various constant current densities. An anodic porous alumina film with a cell size of 200-450 nm grew uniformly on an aluminum substrate by rhodizonic acid anodizing at 5-40 Am -2 , and a black, burned oxide was formed at higher current density. The cell size of the porous alumina increased with current density and corresponding anodizing voltage. Anodizing in croconic acid at 293 K caused the formation of thin anodic porous alumina films as well as black, thick burned oxides. The uniformity of the porous alumina improved by increasing the temperature of the croconic acid solution, and anodic porous alumina films with a uniform film thickness were successfully obtained. Our experimental results showed that the cyclic oxocarbon acids croconic and rhodizonic acid could be employed as a suitable electrolyte for the formation of anodic porous alumina films.Key words: Aluminum; Anodizing; Anodic Porous Alumina; Croconic Acid; Rhodizonic Acid IntroductionThe anodizing of aluminum in several different acidic solutions causes the formation of anodic porous alumina (i.e., porous anodic oxide film) with characteristic nanofeatures on aluminum substrates. Porous alumina consists of nano-scale hexagonal cells perpendicular to the substrate, and each cell possesses a nanopore at its center [1,2]. These cells are self-ordered by anodizing under appropriate electrochemical conditions, especially under a high electric field [3,4]. When anodic porous alumina is immersed in boiling distilled water after anodizing, the nanopores are filled by hydroxide (pore-sealing) [5,6]. The sealing process causes the formation of a highly crystalline hydroxide layer on the surface of the anodic oxide, and the hydroxide layer is highly dissolution-resistant in acidic and alkaline solutions. Using these characteristic structural and chemical properties, anodic porous alumina has been widely investigated for many applications: antireflection structures [7,8] [50] acid have been reported to date for the fabrication of anodic porous alumina. Oxalic and malonic acid anodizing have been reported to give rise to self-ordering behavior under suitable anodizing conditions. The organic and inorganic electrolytes used to fabricate anodic porous alumina possess low dissociation constant (pKa) in aqueous solution, except for glycolic and formic acid, are diacids or triacids. However, glycolic and formic acid form dimers via hydrogen bonding in aqueous solution and may behave like diacids [52,53]. The nanofeatures of anodic porous alumina, including cell size (i.e., interpore distance) and pore diameter, are limited by these electrolytes during anodizing. Therefore, the discovery of additional electrolytes is very important in expanding the applicability of porous alum...

Anodic oxide fabricated by anodizing has been widely used for nanostructural engineering, but the nanomorphology is limited to only two oxides: anodic barrier and porous oxides. Therefore, the discovery of an additional anodic oxide with a unique nanofeature would expand the applicability of anodizing. Here we demonstrate the fabrication of a third-generation anodic oxide, specifically, anodic alumina nanofibers, by anodizing in a new electrolyte, pyrophosphoric acid. Ultra-high density single nanometer-scale anodic alumina nanofibers (1010 nanofibers/cm2) consisting of an amorphous, pure aluminum oxide were successfully fabricated via pyrophosphoric acid anodizing. The nanomorphologies of the anodic nanofibers can be controlled by the electrochemical conditions. Anodic tungsten oxide nanofibers can also be fabricated by pyrophosphoric acid anodizing. The aluminum surface covered by the anodic alumina nanofibers exhibited ultra-fast superhydrophilic behavior, with a contact angle of less than 1°, within 1 second. Such ultra-narrow nanofibers can be used for various nanoapplications including catalysts, wettability control, and electronic devices.