Volume 70, Issue 7

Selected dialkyl azulenedicarboxylates were prepared by carbo-bromination of alkyl azulenemonocarboxylates and subsequent alcoholysis or by alkoxycarbonylcarbene insertion of ethyl indane-2-carboxylate. The electrochemical behavior of the diesters was studied by means of differential pulse polarography and cyclovoltammetry. In-situ electroreduction of the azulenedicarboxylic esters led to the corresponding radical anions, the EPR spectra of which were recorded. For certain radical anions a rearrangement under migration of the functional group from the 5- into the 6-position was observed. The spin density distribution in these non-alternant π -electron systems as determined from the proton hyperfine structure (hfs) coupling constants was compared with the results of MO calculations and discussed with respect to the influence of substituents.

A copper(II) polymeric complex {[Cu(phen) 2 (CN)][Ag(CN) 2 ] · 3H 2 O} n , 1 (phen = 1,10-phenanthroline), has been prepared and structurally characterized. The compound crystallizes in the monoclinic space group P 2 1 / c with [Cu(phen) 2 (CN)] + and [Ag(CN) 2 ] − units and three water molecules. The cationic and anionic units are linked to each other through M- π and π – π interactions. The array is extended further by hydrogen bonding and π – π interactions to form a 3D network.

A new polyoxometalate (POM)-based inorganic–organic hybrid compound, [Ag 2 (bib) 3 ][H 2 SiW 12 O 40 ] ( 1 ), has been hydrothermally synthesized and characterized by routine methods. Single-crystal X-ray diffraction analysis reveals that inorganic supramolecular chains constructed of POM and [Ag 2 (bib) 3 ] subunits are fused together via the Ag cations forming a 3D supramolecular structure. The structure possesses the moganite-type topology. The photocatalytic properties have been investigated through the oxidative decomposition of Rhodamine-B dye.

Two new organically templated borates, [(1,10-phen)(H 3 BO 3 ) 2 ] ( 1 ) and [2-EtpyH][(B 5 O 6 (OH) 4 ] ( 2 ), were synthesized under mild solvothermal conditions and characterized by single-crystal X-ray diffraction, FT-IR, elemental analyses and thermogravimetry. Complex 1 is a co-crystal component in which B(OH) 3 molecules form crinkled tapes via hydrogen bonds, which in turn are packed in a two-dimensional framework with 1,10-phen molecules sandwiched between the framework of crinkled chains. The structure of complex 2 is composed of 2-ethylpyridinium cations [2-EtpyH] + and pentaborate anions [B 5 O 6 (OH) 4 ] – which are linked together with hydrogen bonds to form a three-dimensional supramolecular framework. The templating [2-EtpyH] + cations are situated in the cavities arising from the supramolecular pentaborate framework and interact also with the inorganic framework through hydrogen bonds.

The investigation of different oxide surfaces revealed that nanoporous silica (MCM-41) had the best catalytic activity for Paal–Knorr pyrrole synthesis. Despite the same composition, MCM-41 proved to be more effective than SiO 2 itself, probably due to a significantly higher surface area of the SiO 2 nanopores. The important features of this “clean” solvent-free protocol are the ease of recovery and the reuse of the catalyst for several cycles, operational simplicity, and easy product isolation and purification.

A series of 4-arylacetamido-2-amino- and 2-arylamino-1,3-thiazoles ( 4a – o ) were synthesized in a single step in high yields from ω -bromoacetoacetanilides and thiourea/phenyl thioureas and were characterized by spectral and analytical methods. The compounds were evaluated for their in vitro antibacterial antifungal and antioxidant activities. In vitro antimicrobial evaluation of these compounds indicated their specificity towards Gram-positive species. p -Tolyl and m -chlorophenyl substituents on the arylamino moiety (compounds 4b and 4g ) exhibited the lowest minimum inhibitory concentration values. The other compounds exhibited promising antimicrobial and moderate antioxidant activity.

Three new acesulfamate salts, NaC 4 H 4 NO 4 S, RbC 4 H 4 NO 4 S and CsC 4 H 4 NO 4 S, were prepared by reactions in aqueous solutions and thoroughly characterized. Their crystal and molecular structures were determined by single crystal X-ray diffraction methods. They crystallize in the monoclinic space group P 2 1 / a with a = 7.2518(2), b = 8.9414(4), c = 10.5929(4) Å, β = 99.951(3)°, V = 676.52(4) Å 3 for the Na salt; a = 7.4663(3), b = 9.6962(4), c = 10.4391(4) Å, β = 95.150(3)°, V = 752.68(5) Å 3 for the Rb salt and a = 7.5995(4), b = 9.9439(4), c = 10.8814(6) Å, β = 91.298(5)°, V = 822.08(7) Å 3 for the Cs salt, and Z = 4 molecules per unit cell. The three compounds are isotypic to each other and to the previously reported potassium salt. The metal ions are in irregular polyhedral coordination with six neighboring acesulfamate anions through their nitrogen and carbonyl and sulfoxide oxygen atoms. The FTIR spectra of the compounds were also recorded and are briefly discussed.

The ternary indide Nd 39 Ir 10.98 In 36.02 was synthesized by arc-melting and characterized by single crystal X-ray diffraction. Nd 39 Ir 10.98 In 36.02 crystallizes with a new structure type: Pearson code oP172, Pbam , a = 3175.4(6), b = 3762.5(8), c = 378.02(8) pm, wR 2 = 0.0828, 5544 F 2 values, and 262 variables. Although the structure contains 44 crystallographically independent sites, it can easily be explained as an intergrowth structure of CsCl and AlB 2 related slabs. The larger indium atoms fill all distorted CsCl slabs. The trigonal prismatic (AlB 2 ) slabs have no uniform size. The larger ones are filled by indium and the smaller ones by the iridium atoms. Additionally, one trigonal prism shows a mixed occupancy by indium and iridium. The crystal chemistry of Nd 39 Ir 10.98 In 36.02 is discussed in the context of other intergrowth structures with the same simple slabs.

Two new complexes, [Ni(pydc)(H 2 O) 3 ] ( 1 ) and [Ni(cma)(H 2 O) 3 ] ( 2 ) (H 2 pydc = pyridine-2,6-dicarboxylic acid, H 2 cma = 2-(carboxymethoxy)benzoic acid), have been synthesized and structurally characterized. In both compounds, Ni II is surrounded by one tridentate chelate dianionic ligand (pydc 2 ˉ for 1 and cma 2 ˉ for 2 ) and three coordinated water molecules in a distorted octahedral geometry (NiNO 5 for 1 and NiO 6 for 2 ). The magnetic properties for 1 and 2 have been discussed in detail.

New hybrid molecules containing fluoroquinolone-barbiturate moieties were synthesized via simple routes, followed by characterization using various spectroscopic approaches. The THF solvent molecule was incorporated into compounds 2 and 3 through its oxygen atom based on its nucleophilicity. Facile displacement of the chloride ion in 4-oxoquinoline-3-carbonyl chloride by the nucleophilic methylene carbon of 1,3-dialkylbarbiturate/thiobarbiturate afforded the respective hybrids 5 and 6 .

Searching for new anti-inflammatory and analgesic agents, we have prepared a series of novel pyrazoles containing benzofuran and trifluoromethyl moieties. The pyrazole derivatives have been synthesized via two routes starting from 5-(3-(trifluoromethyl)phenyl azo) salicylaldehyde. The first route involved the synthesis of 2-acetylbenzofuran and then treatment with aldehydes to afford the corresponding chalcones. The cyclization of the latter chalcones with hydrazine hydrate led to the formation of new pyrazoline derivatives. The second route involved the synthesis of benzofuran-2-carbohydrazide and then treatment with formylpyrazoles, chalcones and ketene dithioacetal derivatives to afford the corresponding pyrazole derivatives. Some of the synthesized compounds exhibited anti-inflammatory and analgesic activities.