M 4 Ag 44 (p-MBA) 30 molecular nanoparticles, where M is an alkali metal, have recently been shown to have exceptional stability, which confers unique traits to this molecule. In particular, the synthesis is straightforward, produces a truly single-sized molecular product, and has a quantitative yield. Here we describe in detail the results of experimental and theoretical studies on the synthesis, structure, stability, and electronic and optical properties of M 4 Ag 44 (p-MBA) 30 , including ESI-MS, NMR, optical absorption, IR, TGA, and other measurements as well as DFT and TDDFT calculations. This work deepens our understanding of this important Ag molecule, which should facilitate its use in a wide range of fundamental studies and applications.

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The interchange reaction in blends of poly (ethylene terephthalate) (PET) and poly(m-xylylene adipamide) (MXD6) has been characterized in terms of changes observed in spectra obtained with a 600-MHz 1 H-NMR. The selective degradation of PET components in the blends was carried out in the NMR tubes prior to evaluation. Results indicate that there is no chemical reaction between the PET and MXD6 in the absence of sodium p-toluenesulfonate catalyst. The presence of the catalyst activates the interchange reaction between these two resins. A mathematical method was applied to calculate the degree of randomness of PET-MXD6 copolymer. In addition, the reaction degree was found to be affected by exposure temperature, time, shear rate, and catalyst concentration.

Hydrozirconation of 1-alkynyl pinacolboronates, 1, with HZrCp2Cl provides gem-borazirconocenes 2. The latter when treated with CuBr gives the homocoupled (1E,3E)-2,3-dibora-1,3-butadienes, 3, in good yield (62−67%). The reaction works even for hindered 2 (R = t-Bu). Structure 3 was assigned on the basis of NMR. Suzuki−Miyaura coupling of 3a (R = n-Bu) with PhI in the presence of CsF leads to the replacement of both boron groups by phenyl and hydrogen to give 6 in 76% yield. Zirconocene-mediated coupling of 1 leads to diastereomeric products:  (1E,3E)-1,3-dibora-1,3-butadienes, 4, in 7−26% isolated yields and (1E,3E)-1,4-dibora-1,3-butadienes, 5, in 17−34% isolated yields. The two isomers can be separated by selective precipitation of 5 from the reaction mixture in pentane (−20 °C) followed by silica gel chromatography to give pure 4. The reaction does not work when R in 1 is the t-Bu group. Assignments of structures for 4 and 5 were done on the basis of 1D and 2D NMR experiments. In addition, a single-crystal X-ray analysis of 5a showed it to be a highly planar and linearly oriented molecule. Suzuki−Miyaura coupling of 4a proceeded to replace the terminal boron group exclusively, while the internal boron group of 4a remained intact.

The acid H(2)B(12)(OH)(12) can be isolated as a crystalline solid by protonation of the hydroxylated borane anion, B(12)(OH)(12)(2)(-). This acidic compound has low solubility in water, conducts protons in the solid state, and has thermal stability to a temperature of 400 degrees C. The conductivity mechanism is a Grotthuss mechanism with a low activation enthalpy (9-13 kcal/mol). This new acid represents an addition to the class of oxoacids, of which sulfuric and phosphoric acid are the most prominent examples.