The formation of the large protein structure known as "gluten" during dough-mixing and bread-making processes is extremely complex. It has been established that a specific subset of the proteins comprising gluten, the glutenin subunits, directly affects dough formation and breadmaking quality. Glutenin subunits have no definitive structural differences that can be directly correlated to their ability to form gluten and affect dough formation or breadmaking quality. Many protein structural studies, as well as mixing and baking studies, have postulated that disulfide bonds are present in the gluten structure and contribute to the process of dough formation through the process of disulfide-sulfhydryl exchange. Evidence presented here indicates that tyrosine bonds form in wheat doughs during the processes of mixing and baking, contributing to the structure of the gluten network. The relative contributions of tyrosine bonds and disulfide--sulfhydryl interchange are discussed.

The p-styrenyl substituent borne by the organoimido ligand in the Lindqvist derivative [NBu 4 ] 2 [Mo 6 O 18 (NC 6 -H 4 CHNCH 2 )] 1 allows the polyoxometalate complex to be introduced as a pendant group in polystyrene compositions via conventional free radical-induced copolymerization.

Osmium Osmium I 8100 Functionalized Heteropolyanions: High-Valent Metal Nitrido Fragments Incorporated into a Keggin Polyoxometalate Structure. -Three new nitrido-functionalized polyoxotungstates are synthesized which feature the incorporation of [Os VI ≡N] 3+ (III), [Re VI ≡N] 3+ (V), and [Re VII ≡N] 4+ fragments into the framework of a Keggin-type heteropolyanion. Compound (III) is characterized by 15 N, 31 P, and 183 W NMR and for (V) results obtained by EPR spectroscopy (confirming the paramagnetic character), cyclic voltammetry, and single crystal XRD (cubic, space group Im3m) are briefly reported. -(KWEN, H.; TOMLINSON, S.; MAATTA*, E. A.; DABLEMONT, C.; THOUVENOT, R.; PROUST, A.; GOUZERH, P.; Chem.

A new metathetical route to diazoalkane complexes is described which allows the introduction of such ligands into previously inaccessible environments. The method, which involves the exchange of oxo and [N2 CR2 ] ligands, is illustrated by the preparation of the first diazoalkane-polyoxometalate complex 1.

A series of solid sorbent materials, including alumina (Al 2 O 3 ), magnesia (MgO), titania (TiO 2 ), silica (SiO 2 ), and carbon, of widely varying physical properties, have been studied as sorbents for two toxic substances: sulfur dioxide gas (SO 2 ) and chemical warfare surrogate 2-chloroethyl ethyl sulfide (2-CEES, ClCH 2 CH 2 SCH 2 CH 3 ). Sorbent surface areas, average pore sizes, pore volumes, surface hydroxyl groups, and nitrogen adsorption-desorption isotherms were measured. Surface areas varied from 18 m 2 /g to over 1000 m 2 /g, pore volumes from 0.04 to 1.2 cm 3 /g, and pore diameters from 1.7 to 4.9 nm. Breakthrough studies of SO 2 and 2-CEES sorption yielded information about the effectiveness of each sorbent. Carbon samples worked well for 2-CEES but not SO 2 , while silica samples were poor for both. The best MgO and TiO 2 samples were good for both SO 2 and 2-CEES, and overall, the highest surface area (459 m 2 /g) TiO 2 sample was the superior sorbent. The important features for an effective sorbent under the conditions employed are high surface area and high pore volume, possessing isolated surface -OH groups, mesoporous nature, and a polar surface (Lewis base and Lewis acid sites).

Nanorods of magnesium oxychloride (Mg x (OH) y Cl z ·nH2O) and magnesium hydroxide (Mg(OH)2) have been produced from crystalline MgO. Concentrated aqueous magnesium chloride (MgCl2·6H2O), when allowed to react with MgO, yields oxychloride nanorods that can be converted into Mg(OH)2 nanorods using NaOH, with retention of the nanorod morphologies. A comparison of powdered MgO starting materials has shown that, by proper choice of reagent concentrations, temperature, and aging time, nanorods can be obtained in all cases, but nanocrystalline (NC)−MgO gives the highest yields and the highest aspect ratios (aspect ratios of about 60−90 in the oxychloride system). The higher surface area and higher reactivity of NC−MgO allow the rapid formation of nucleation sites in large numbers that subsequently grow into thin (∼170 nm) oxychloride nanorods. The nanorods of Mg x (OH) y Cl z ·nH2O and Mg(OH)2 were characterized by powder X-ray diffraction and transmission electron microscopy measurements.

Three examples of nitrido-functionalized polyoxometalate species are reported, namely (n-Bu4N)4[PW11O39(OsN)] (1), (n-Bu4N)4[PW11O39(ReN)] (2), and (n-Bu4N)3[PW11O39(ReN)] (3), which feature the incorporation of [OsVI identical to N]3+, [ReVI identical to N]3+ and [ReVII identical to N]4+ fragments, respectively, into the framework of a Keggin-type heteropolyanion.

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