1,1′‐Di­acetyl‐3‐hydroxy‐2,2′,3,3′‐tetra­hydro‐3,3′‐bi(1H‐indole)‐2,2′‐dione

In the title compound, C₂₀H₁₆N₂O₅, both of the 1‐acetyl­isatin (1‐acetyl‐1H‐indole‐2,3‐dione) moieties are planar and form a dihedral angle of 74.1 (1)°. Weak intermolecular hydrogen bonds and C—H?π interactions stabilize the packing in the crystal.     

Potential anti-inflammatory diterpenes from Premna obtusifolia

Eleven new diterpenoids: pimaranes (1,2), rosanes (3) abietanes (4–7), icetexanes (8), and rearranged icetexanes (9–11), together with fifteen known diterpenes (12–26) and two known sesquiterpenes (27,28) have been isolated from the roots and twigs of Premna obtusifolia. The structures of these compounds were elucidated on the basis of spectroscopic analysis and X-ray crystallographic data of 8 and 9 were also determined. The antibacterial and anti-inflammatory activities of the isolates were evaluated.     

Synthesis,Crystal Structures and Properties of Tetrametallic Complexes: [M2(phen)4(FCA)2](ClO4)2·(H2O)2 (M=Zn or Co,phen=1,10‐phenanthroline,FCA=anion of 3‐ferrocenyl‐2‐crotonic acid)

Two new complexes [Zn₂(phen)₄(FCA)₂](ClO₄)₂·(H₂O)₂ ( 1 ) and [Co₂(phen)₄ (FCA)₂](ClO₄)₂·(H₂O)₂ (2) (FCA=anion of 3‐ferrocenyl‐2‐crotonic acid, phen=1,10‐phenanthroline) have been synthesized, and characterized by elemental analysis, IR, UV‐Vis spectra, thermal analyses, and single‐crystal X‐ray diffraction. Two M(II) (M=Zn or Co) ions are bridged by two FCA anions with syn‐anti bridging ligands, leading to dimeric cores, [M₂(phen)₄(FCA)₂]²⁺, and each M(II) ion is six‐coordinated in a distorted octahedral geometry by two chelate phen ligands and two μ₂‐carboxylate oxygen atoms from two FCA groups. The M(II)…M(II) intradimer distances are 0.4391 and 0.4462 nm in 1 and 2 , respectively. Electrochemical properties of the complexes have been discussed.     

1-Acetyl-3-[benzoyl(4-methoxy­phenyl)­methyl­ene]-2,3-di­hydro-1H-indol-2-one

In the title compound, C₂₅H₁₉NO₄, the indole moiety is not completely planar, the heterocyclic ring being distorted very slightly towards a half-chair conformation. The benzoyl and 4-­methoxy­phenyl substituents are individually almost planar and are in a bisecting and nearly perpendicular configuration, respectively, with respect to the plane of the indole moiety. The molecular and packing structures in the crystal are stabilized by intramolecular and intermolecular C—H⋯O interactions.     

Electrospun fiber mats of poly(3‐hydroxybutyrate), poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate), and their blends

Electrospinning of poly(3‐hydroxybutyrate) (PHB), poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV), and their blends was first carried out in chloroform at 50 °C on a stationary collector. The average diameter of the as‐spun fiber from PHB and PHBV solutions decreased with increasing collection distance and increased with increasing solution concentration and applied electrical potential. In all of the spinning conditions investigated, the average diameter of the as‐spun pure fibers ranged between 1.6 and 8.8 μm. Electrospinning of PHB, PHBV, and their blends was carried out further at a fixed solution concentration of 14% w/v on a homemade rotating cylindrical collector. Well‐aligned, cross‐sectionally round fibers without beads were obtained. The average diameter of the as‐spun pure and blend fibers ranged between 2.3 and 4.0 μm. The as‐spun fiber mats appeared to be more hydrophobic than the corresponding films and much improvement in the tensile strength and the elongation at break was observed for the blend fiber mats over those of the pure fiber ones. Lastly, indirect cytotoxicity evaluation of the as‐spun pure and blend fiber mats with mouse fibroblasts (L929) indicated that these mats posed no threat to the cells. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2923–2933, 2006     

Amidinokomplexe von Molybdän(V) und Rhenium(V) Die Kristallstruktur von [Cl4Mo{i-Prop-NC(Cl) N-i-Prop}]

Amidinocomplexes of Molybdenum (V) and Rhenium (V). Crystal Structure of [Cl₄Mo{i-Prop-NC(Cl) N-i-Prop}] Molybdenum pentachloride and rhenium pentachloride, respectively, react with di-isopropylcarbodiimide in CCl₄?suspensions forming the monomeric amidino complexes [Cl₄M{i-prop-NC(Cl)N-i-prop}] (M = Mo, Re). According to the i.r. spectra the C? Cl-amidino ligand is bonded as a chelate. The molybdenum complex is characterized by an X-ray structure determination. It crystallizes in the tetragonalic space group I4₁/a with 8 formula units in the unit cell (1538 independent, observed reflexions, R = 0.051) with the lattice constants a = 1119 and b = 2332 pm.     

X-ray crystallography and magnetic studies of a stable macrocyclic tetranitroxide. Intramolecular dimer of nitroxides in a constrained geometry of the upper rim of calix[4]arene

Synthesis, crystallography, and magnetic characterization of a stable macrocyclic tetranitroxide 1, a calix[4]arene, which is functionalized with four tert-butylnitroxides at the upper rim, is described. In solution, 1 has a 4-fold symmetric fixed cone conformation on the NMR time scale and small, but nonnegligible, exchange interactions between the radicals (30 K > /J/k/ >1.8 mK). In the solid state, dimerization of one diagonal pair of nitroxides leads to a pinched cone conformation for 1 with strong intradimer antiferromagnetic coupling with /J/k/ = 200-300 K (singlet-triplet energy gap, DeltaE(ST) approximately 1 kcal/mol).