the coupling of tetrazotised 1,8-diaminonaphthalene with 1,3-dicarbonyl compounds [acetylacetone,methylacetoacetate and acetoacetanilide] yielded a new series of tetradentate ligand systems. analytical, ir,1h nmr and mass spectral data indicate that the compounds exist in the intramolecularly hydrogen bondeddihydrazone form. dibasic tetradentate n2o2 coordination of these compounds in their [ml...

in this paper, tin dioxide nanoparticles were synthesized by a fast and simple co-precipitation method. for sno2 preparation, we used ammonia as precipitation agent and bis (acetylacetone) ethylene diamineas as capping agent. by changing in sncl4, acacen mole-ratio different morphologies were obtained. this semiconductor nanostructure has photo-catalyst activities and can degrade organic dyes a...

We demonstrated self-patterned solution-processed amorphous oxide semiconductor thin-film transistors (TFTs) using photosensitive sol-gels. The photosensitive sol-gels were synthesized by adding β-diketone compounds, i.e., benzoylacetone and acetylacetone, to sol-gels. The chemically modified photosensitive sol-gels showed a high optical absorption at specific wavelengths due to the formation o...

The X-ray structure of (Tl[Au(C(6)Cl(5))(2)])(n), 1, consists of 1-D linear polymer chains parallel to the crystallographic z axis. The crystal structure of 1 has channels that run parallel to these chains with interatom distances in the range 3.231-4.076 A. There are holes in these channels with diameters as large as 10.471 A, which can accommodate a variety of solvents. Complex 1 displays rev...

Despite the wide applicability of enantioselective Brønsted acid catalysis, experimental insight into transition states is very rare, and most of the mechanistic knowledge is gained by theoretical calculations. Here, we present an alternative approach (decrypting transition state by light = DTS-hν), which enables the decryption of the transition states involved in chiral phosphoric acids cataly...

Glucosamine has been selected as a cheap and readily available chiral scaffold for the synthesis of a series of novel enantiomerically pure bifunctional organocatalysts bearing a tertiary amino group in proximity to a (thio)urea group. The catalytic behaviour of these compounds, both as neutral and N-protonated species, was investigated using the addition of acetylacetone to β-nitrostyrene as a...

Acetylacetone dioxygenase from Acinetobacter johnsonii (Dke1) is a non-heme Fe2+ dependent enzyme which catalyzes the oxidative degradation of β-dicarbonyl compounds. It is a homotetramer with four active sites, each containing single metal ion. Since the active site is buried, knowledge on transport of the metal ion and reactants (products) is essential for understanding the enzyme mechanism. ...

AIM To examine formaldehyde release from three different root-canal sealers: one phenol resin, one epoxy resin and one paraformaldehyde containing zinc oxide eugenol cement. METHODOLOGY Formaldehyde was measured from freshly mixed material and from specimens allowed to set for 2 days or 2 weeks. Different mixing ratios and sample sizes were tested. Analysis was performed by reacting formaldeh...

A novel series of cyanopyridinyl tetrahydronaphthalene incorporated with different heterocycles were synthesized. The key compounds 2a,b were condensed with chloroacetone and ethyl chloroacetate to give 3a,b and 4a,b, respectively. Also condensation of 4a,b with hydrazine hydrate gave the corresponding hydrazide 5a,b. Reaction of 5b with different isothiocyanates gave the corresponding thiosemi...