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The urgency of water remediation and the conversion of toxic pollutants into non-toxic compounds is increasingly crucial in our industrialized world. Heterogeneous catalysts based on metal nanoparticles, which are cost-effective, non-toxic, and readily available, have garnered significant attention in the market due to their unique catalytic properties. This study presents sol–gel-based hybrid silica matrices that encapsulate nickel, designed for the efficient reductive de-halogenation of tri-bromoacetic acid (TBAA), di-bromoacetic acid (DBAA), mono-bromoacetic acid (MBAA), tri-chloroacetic acid (TCAA), mono-chloroacetic acid (MCAA), and Chloroacetanilide (CAA). A detailed study of the product distribution from each halo-acetic acid (HAA) is presented. The study points out that other products are formed from Ni-catalyzed reduction reactions of HAAs, breaking the conventional rules of stepwise reduction mechanisms. The plausible mechanisms of the catalytic processes are discussed. [ABSTRACT FROM AUTHOR]

The kinetics of the reactions of H2 with rhodium and iridium nanoparticles (NPs), in aqueous suspensions, were studied by following their catalytic reduction of PW12O403−, POM. The reaction of H2 with the same size (∼2.5 nm) of two different nanoparticles was carried out to check how the nature of the nanoparticles affects the reaction kinetics. Herein we report the first kinetic measurement of H2 + Rh0 and Ir0 NPs in the absence of an electric field. A comparison of the apparent rate constants of the reactions Rh0-NPs and Ir0-NPs + H2 to the previously reported Pt0-NPs + H2 indicates that the rates decrease along the series k(Pt) > k(Rh) > k(Ir), though they are of the same order of magnitude. The adsorption of hydrogen and/or H atom can affect the structure of the M0-NPs. [ABSTRACT FROM AUTHOR]

The studies, relating to the straightforward electrosynthesis of novel polycarboxylated conducting polyCbz-films from one carboxylated Cbz-containing building block as new electro-oxidizabel peripheral species, are reported. The postpolymerization covalent grafting of biomolecules onto these fabricated conducting surfaces should pave the way for the development of numerous applications in the biosensing field.

Research has been conducted on octaethyl triptycenes. The synthesis of these compounds has been carried out via Diels-Alder reaction of benzynes and octaethylanthracene and the details are reported.

Research has been conducted on the 1,2,3,4,5,6,7,8-octaethylanthracene, 1,2,3,4,6,7,8-heptaethylfluorene, and 1,2,3,4,5,6,7,8-octaethylfluorene. The synthesis of these compounds has been carried out via Friedel-Crafts ethylations of 9,10-dihydroanthracene and fluorene and the results of the MM3 calculations indicate that two of the ethylated rings are conformationally independent.

Dimerization of tetraethylbenzyne afforded in low yield octaethylbiphenylene, together with a major product which was characterized as 2,3,4,5,3',4',5'-heptaethyl-2'-vinylbiphenyl. The similarity in rotational barriers suggests that a given tetrathylphenylene subunit does not markedly affect the rotational barrier of the ethyl groups of the other subunit.

Studies of the stereochemistry of polysubstituted benzene systems have been extensive, but there have been few studies on the static and dynamic stereochemistry of deca-substituted biphenyl derivatives. The static and dynamic stereochemistry of decasubstituted biphenyls, having 10 identical side chains of form CHsub2Y, is reported. The preparation, crystal structure, rotational barrier and solution conformation of biphenyl analog of hexaethylbenzene is also described.

The NMR spectra of several N-Boc-amino acids and their methyl esters indicate that hydrogen bonding stabilizes the syn-rotamers of the Boc-carbamate analogs of alpha-amino acids. Specifically, temperature- and concentration-dependent hydrogen bonding with carboxylic groups in solution was found to induce the formation of an unusual carbamate species corresponding to the syn-rotamer of unsaturated N-Boc-amino acids in addition to the expected product. This effect held true for all species studied, including N-Boc-alpha-aminobutyric acid, N-Boc-(4-methoxyphenyl)glycine and a saturated analog of N-Boc vinylglycine.

Three aci-reductones are synthesized, and their reaction with superoxide anion radical is an easy deprotonation. The triketone is the next important product in the reaction pathway giving reductone monoanion. At the central carbonyl the superoxide attacks which leads to oxidative cleavage and/or benzylic acid rearrangement. Several base catalyzed autoxidative processes occur that are substrate dependent.

Newly synthesized 4,4,6-trisubstituted-2-hydroxy- and -2-alkoxycyclohexa-2,5-dien-1-ones possess H, CH3, Ph, tert-butyl or OEt at C-6. The C-4 substituent moves regioselectively to C-5. The enol double bond is avoided despite the larger substituents at C-6. The electronic factors determine the regioselectivity of the dienone-phenol rearrangement.

An investigation of 1,3-dipolar cycloaddition of trimethylsilyldiazomethane with alpha,beta-unsaturated esters is presented. It is demonstrated that the distribution of 2-pyrazoline products is highly dependent on the relative configuration of the substituents on the 1-pyrazoline intermediate.

Research has been conducted on acylated tetrahydrobenzazepines. The authors report that the results of high-field NMR analysis of these compounds demonstrate the existance of the heterocyclic ring in the compounds in a chair conformation.

Research has been conducted on octakis(bromomethyl)naphthalene. The conformation, crystal structure and rotational barrier of this crowded multiarmed compound are discussed.