Volume 70, Issue 5

Equiatomic Ce TX intermetallics with the hexagonal ZrNiAl type structure are formed with electron-rich transition metals ( T ) and X = Mg, Zn, Cd, Al, Ga, In, Tl, Sn, and Pb. Their crystal chemistry, chemical bonding, magnetic and electrical properties, and formation of solid solutions are reviewed. The results of 119 Sn Mössbauer spectroscopy, high-pressure studies, and hydrogenation reactions are presented.

Pyrazoles 4a–f , hydrazones 5a–c and 6a–c , pyrazolo[1,5- a ]pyrimidines 7a , b , and pyrazolo[3,4- b ]pyridine 8 were prepared in good yields (80–95 %) from the reaction of 6-substituted (H, Me, F) 3-formylchromones 1a–c with N -substituted hydrazines 2a–c and aminopyrazole 3 . The cytotoxicity of the synthesized compounds was assessed through the brine shrimp lethality assay. IC 50 values were between 80 and 300 μ m . Fluorine substitution decreased IC 50 values.

An organic-inorganic hybrid compound based on {PMo 12 } layers, [Ag(pz) 2 ] 6 [PMo 12 O 40 ] 2 ·3H 2 O 1 (pz = pyrazole), has been hydrothermally synthesized and characterized by elemental analysis, TG, IR spectroscopy, and single-crystal X-ray diffraction. Two crystallographically independent [PMo 12 O 40 ] 3– clusters are arranged in an AB–AB mode to give two kinds of supramolecular layers. The layers are further connected in a special alternating mode by [Ag(pz) 2 ] + linkers to form complex 3-D supramolecular network. Compound 1 exhibits good electrocatalytic activity in the reduction of hydrogen peroxide and shows fluorescence in the solid state at room temperature.

Alkyl-substituted ferrocenes are typical burning-rate catalysts in composite solid propellants, but their high migration tendency and volatility has impeded their extensive applications. By introducing the concept of ionic energetic compounds, eight new ionic binuclear ferrocenyl compounds, [FcCH 2 N(CH 3 ) 2 (CH 2 ) n N(CH 3 ) 2 CH 2 Fc] 2+ (X – 2 ) (Fc = ferrocenyl; X – = 1,1,3,3-tetracyano propenide; n = 3–10; the compounds being numbered consecutively 1 – 8 ), were prepared and characterized. The molecular structures of 1 , 2 , and 4 were determined by single-crystal X-ray diffraction, and their cations were studied by density functional theory calculations (DFT). Compounds 1 – 5 show high thermal stability but 6 – 8 are slightly volatile. The results of cyclic voltammetry studies suggest that each salt exhibits a quasireversible redox system. Catalytic effects of the new salts on thermal degradation of ammonium perchlorate (AP), 1,3,5-trinitro-1,3,5-triaza-cyclo-hexane (RDX), and 1,2,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), have been investigated by DSC and/or TG methods. The results show that the new compounds can bring the peak temperatures of both AP and RDX down significantly and enhance their heat release dramatically, indicating that the ferrocenyl salts possess high catalytic efficiency for the thermal decomposition of AP and RDX. Their catalytic activities are nearly equal to or higher than that of the corresponding nitrates and picrates, as well as their mononuclear counterparts. Compound 6 also efficiently catalyzes the thermal decomposition of hydroxyl-terminated polybutadiene (HTPB) and 1:1 mixtures of HTPB and AP.

Zusammenfassung: Die Reaktion von 1,5-Bis(trimethylsilyl)-1,3,5-trimethylbiuret mit Di- bzw. Monochlorphosphanen führte unter Bildung von Me 3 SiCl zu den 1,3,5-Trimethyl-1,3,5-triaza-2 σ 3 λ 3 -phosphorinan-4,6-dionen 1 – 4 bzw. zu den 1,5-Bis(phosphano)-1,3,5-trimethylbiuret-Derivativen 5 und 6 . Verbindungen 1 , 2 und 4 wurden mittels Einkristall-Röntgenstrukturanalyse charakterisiert. Alle Heterozyklen wiesen eine flache Boot-Konfiguration auf, wobei das Phosphoratom und das gegenüberstehende Stickstoffatom außerhalb der Ebene der restlichen Atome lagen. Oxidation der σ 3 λ 3 P-Derivative mit dem 1:1-Harnstoff/Wasserstoffperoxid-Addukt lieferte die entsprechenden 2-Oxo-2 σ 4 λ 5 -phosphorinan-4,6-dionen 8 – 11 und die 1,5-Bis(phosphoryl)biuret-Derivate 12 und 13 . Die Spirophosphorane 15 – 22 wurden bei der Reaktion von 1 – 4 mit Tetrachlor- o -benzochinon, und von 1 , 3 und 4 mit Hexafluoraceton gebildet. Verbindungen 20 und 21 enthalten einen Oxaphosphetanring, der durch die elektronegativen CF 3 -Gruppen stabilisiert wird. Verbindung 22 wurde aus 21 durch Verlust der Trimethylsilylgruppe gebildet.Außer 21 wurden alle Oxaphosphetane über ihre 1 H-, 13 C-, 19 F- und 31 P-NMR-Spektren und mittels E.I.-Massenspektrometrie characterisiert. Auch für 20 wurde eine Einkristall-Röntgenstrukturanalyse durchgeführt; die Koordination am Phosphor ist stark verzerrt trigonal bipyramidal, wobei der Oxetanring eine axiale und eine equatoriale Lage am Phosphor besetzt. Die Reaktion von 1 mit 1-Trifluormethyl-2-(heptafluorisopropyl)-biacetyl lieferte 23 anstatt eines Oxaphosphetans wie 20 .

A new series of 6-amino-5-(aryldiazenyl)- N 1 , N 3 -dimethyl-2-thioxo-pyrimidin-4-one derivatives 17 – 27 and the N 1 -methyl-azothiopyrimidine analog 28 were synthesized from the pyrimidine derivatives 4 and 5 , respectively, via diazotization reaction, with various amines. The platinum(II) metal complexes [bis(4-amino- N 3 -methyl-6-oxo-2-thioxo-pyrimidin-1-yl)]Pt(II) ( 29 ) and [(6-amino-5-(4- R -phenyl)diazenyl)- N 1 ,N 3 -dimethyl-2-thioxo-pyrimidin-4-one)]Pt(II)Cl 2 derivatives 30 – 33 were prepared from the treatment of 5 and the azo analogs 17 and 21–23 with PtCl 2 , respectively. Analogously, 5 and 17 were treated with RuCl 3 ·3H 2 O to give the Ru(III) complexes 34 and 35 , respectively. The newly synthesized compounds were assayed against HIV-1 and HIV-2 in MT-4 cells. The results revealed that 26 and 30 were the only compounds in the series inhibiting HIV replication in cell cultures with an IC 50 value of >2.07 and >3.02 μg mL –1 , respectively. The molecular modeling interactions of 26 with some amino acids of HIV reverse transcriptase were studied. In addition, the antibacterial activity of 17 – 35 and 31 – 33 against Staphylococcus aureus and Escherichia coli was evaluated.

An effective one-pot synthesis of benzene derivatives using a Diels–Alder reaction of activated acetylenes with phosphoryl-2-oxo-2 H -pyrans is described. The latter compounds were synthesized in good yield via the reaction of dialkyl acetylenedicarboxylates and alkyl bromides in the presence of trialkyl phosphites under solvent-free conditions at 50 o C.

Reaction of [Me 4 N] 2 [Cd(TeTol) 4 ] (Tol = 4-tolyl) with two equivalents of [Cu(PPh 3 ) 2 NO 3 ] gave a new soluble tellurolate-bridged heterobimetallic complex of [Cd( μ -TeTol) 4 {Cu(PPh 3 ) 2 } 2 ] ( 1 ) in which two [Cu(PPh 3 ) 2 ] + fragments are chelated at opposite edges of a tetrahedral [Cd(TeTol) 4 ] 2– moiety via the tellurium atoms. Complex 1 is air and optically stable. The nonlinear optical absorption ( α 2 = 7.4 × 10 –4 cm W –1 mol –1 ) and refraction ( n 2 = 2.3 × 10 –9 cm 2 W –1 mol –1 ) were determined by z -scan techniques with 7 ns pulses at 532 nm.