It goes on the dicopper core! A monomeric γ-Keggin silicotungstate with a core that is bridged by two μ-1,1-azido ligands catalyzes oxidative alkyne homocoupling reactions whereby various kinds of aromatic and aliphatic alkynes are selectively converted into corresponding diynes (see picture).

The di- and tetranuclear metal sandwich-type silicotungstates of Cs10[(γ-SiW10O36)2{Zr(H2O)}2(μ-OH)2]·18H2O (Zr2, monoclinic, C2/c (No. 15), a = 25.3315(8) Å, b 22.6699(7) c 18.5533(6) β 123.9000(12)°, V 8843.3(5) Å3, Z 4), Cs10[(γ-SiW10O36)2{Hf(H2O)}2(μ-OH)2]·17H2O (Hf2, space group 25.3847(16) 22.6121(14) 18.8703(11) 124.046(3)°, 8974.9(9) Cs8[(γ-SiW10O36)2{Zr(H2O)}4(μ4-O)(μ-OH)6]·26H2O (Zr4, tetragonal, P41212 92), 12.67370(10) 61.6213(8) 9897.78(17)...

A novel dialuminum-substituted silicotungstate TBA3H[γ-SiW10O36{Al(OH2)}2(μ-OH)2]·4H2O (1, TBA = tetra-n-butylammonium) was synthesized by the reaction of potassium salt [γ-SiW10O36]8− (SiW10) with 2 equiv Al(NO3)3 in an acidic aqueous medium. It confirmed X-ray crystallographic analysis that compound 1 a monomer γ-Keggin {Al2(μ-OH)2} diamond core. The cluster framework maintained structure solution states. pyridine yielded TBA3[(C5H5N)H][γ-SiW10O36{Al(C5H5N)}2(μ-OH)2]·2H2O (2), and...

A series of 2,5-diaryl-3,4-diphenylsiloles, with various mono-substituted phenyl groups, extended pi-conjugated and heteroaryl groups as aryl at the 2,5-positions, has been prepared by a one-pot synthesis from bis(phenylethynyl)silanes based on intramolecular reductive cyclization followed palladium-catalyzed cross-coupling halides. Crystal structures chemical reactivities toward alkaline desilylation reactions have studied 2,5-bis(p-mono-substituted phenyl)silole derivatives to elucidate...

Catalytic alkane hydroxylation activities of the iron complex encapsulated into micropore Y-type zeolite and mesoporous zeolites, latter which were obtained by partial removal aluminum alkaline treatment, have been explored using H2O2 as oxidant. The with tris(pyridylmethyl)amine (=TPA) genuine was a more stable effective cyclohexane hydroxylating heterogeneous catalyst compared to corresponding copper analogue well non-encapsulated homogeneous Fe-TPA complex. chemical modification supports...

A stress-induced substance(s) (factor C) incubated with norepinephrine (NE) has strong flower-inducing activity in Lemna paucicostata. We isolated an essential component (FIF) of factor C, and clarified its chemical structure as 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid, α-ketol derivative linolenic which is formed via 9-hydroperoxy acid. Synthesized FIF showed after incubation NE C activity) equivalent to that the stressed Lemna. Jasmonic acid...

The reaction of the dinuclear peroxotungstate, [(n-C4H9)4N]2[{WO(O2)2}2(mu-O)] (II), with H2O2 gives novel mu-eta1:eta1-peroxo-bridging tungsten species, [(n-C4H9)4N]2[{WO(O2)2}2(mu-O2)] (I), which has been characterized by X-ray crystallography, elemental analysis, IR, Raman, UV-vis, and 183W NMR. Only I is active for epoxidation cyclic, internal, terminal olefins, whereas II inactive each. low XSO (XSO=(nucleophilic oxidation)/(total oxidation)) value (0.18+/-0.02) in comparison that...

A series of the copper(II) complexes with tripodal tetradentate tris(pyridyl 2-methyl)amine-based ligands possessing hydrogen-bonding 6-aminopyridine units (tapa, three amino groups; bapa, two mapa, one group) have been synthesized, and their a small molecule such as dioxygen azide studied spectroscopically structurally. The reaction Cu(II) NaN3 given mononuclear copper in an end-on mode, [Cu(tapa)(N3)]ClO4 (1a), [Cu(bapa)(N3)]ClO4 (2a), [Cu(mapa)(N3)]ClO4 (3a), [Cu(tpa)(N3)]ClO4 (4a) (tpa,...

A novel copper(II)−OOH complex with functional ligand that can form a hydrogen bond the distal oxygen of hydroperoxide has been designed and prepared as structural/functional model dopamine β-hydroxylases, whose spectroscopic characterization decomposition rates have indicated is activated through hydrogen-bonding interaction oxygen.

A novel hydroperoxo-copper(II) complex with a square-planar geometry has been prepared, which exhibited higher selectivity and catalytic reactivity for dimethyl sulfide, in contrast to that trigonal-bipyramidal one.

For developing broader application of biobased polymers, graft copolymers and comb polymers having poly(lactic acid) (PLA) side chains have been synthesized by using a macromonomer technique. PLA macromonomers (MMm) methacryloyl polymerizable group with different chain length an average m = 4, 6, 8, 12, 18, 30 were prepared via ring-opening polymerization l-lactide hydroxyethyl methacrylate (HEMA) initiator catalyzed Sn(Oct)(2). Radical behaviors these examined. copolymerization MMm (m 8),...

[Cu(terpy)]2+ complexes encapsulated into Na-Y zeolite ([Cu(terpy)]2+@Y) were prepared, and their catalytic activities for the oxidation of sulfides using hydrogen peroxide investigated. Several spectroscopic results, as well elemental analysis, demonstrated formation in supercages Y-zeolite. [Cu(terpy)]2+@Y exhibited high selectivity thioanisole methylphenylsulfoxide when H2O2 was used. The kinetic study this at catalyst suggests that reaction species with is rate-determining step....

Abstract

Ruthenium(II/III) complexes with tripodal tris(pyridylmethyl)amine ligands bearing one, two, or three pivalamide groups (MPPA, BPPA, TPPA: amide-series ligands) neopentylamine ones (MNPA, BNPA, TNPA: amine-series at the 6-position of pyridine ring have been synthesized and structurally characterized. The X-ray structure analyses single crystals these reveal that they complete an octahedral geometry ligand some monodentate ligands. prefer to form a Ru(II) complex, while give Ru(III) complex....

Abstract In order to clarify the effect of hydrogen bonding on stabilities (μ‐peroxo)dicopper complexes with a trans ‐μ‐1,2‐peroxo form, novel copper intramolecular interaction sites have been synthesized, and their spectroscopic properties thermal studied. The selected tripodal tetradentate ligands were tris(2‐pyridylmethyl)amine (TPA) derivatives bearing pivalamido amino groups at 6‐position pyridine ring in TPA, {[6‐(pivalamido)pyrid‐2‐yl]methyl}bis(pyrid‐2‐ylmethyl)amine (MPPA)...

A mononuclear copper(II)-hydroperoxo species has been generated by the reaction of Cu(I)-H2BPPA complex with dioxygen, which illustrates enzymatic process CuB site in DbetaM and PHM.

A new μ-η2:η2-peroxo dicopper(II) complex, [CuII2(αSp)2(μ-η2:η2-O2)(Bz-)]SbF6 (αSp = α-isosparteine, Bz- benzoate) was synthesized by oxygenation of [CuI(αSp)(CH3CN)]SbF6 with at −80 °C in acetone. X-ray crystallographic analysis the dark blue crystal revealed that "bridged butterfly core" is formed bridging bound axial position. The weaker σ-electron donation αSp causes coordination to stabilize butterfly-type species as an intermediate stepwise O2-activation bis(μ-oxo) dicopper(III) species.

Katalysator mit Kupferkopf: Ein monomeres γ-Keggin-Silicowolframat Bis-μ-1,1-azidodikupfer-Einheit katalysiert die selektive oxidative Homokupplung von aromatischen und aliphatischen Alkinen zu den entsprechenden Diinen (siehe Bild). Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2001/2008/z705126_s.pdf or from author. Please note: The publisher not responsible content functionality of any supporting supplied by authors. Any queries...

Treatment of dialkylbenzylsilanes (1) with trityl tetrakis(pentafluorophenyl)borate (TPFPB) afforded the corresponding silylium ions in equilibrium their intra- or intermolecular π-complexes, which underwent dehydrogenative annulation various alkenes to form 1,2,3,4-tetrahydro-2-silanaphthalenes (4) up 82% isolated yield. Sterically bulkier substituents on silicon atom tended increase yield cyclic products 4. The retained stereochemistry cases reactions using internal alkenes. use...

Hydrogen atom abstraction reactions have been implicated in oxygenation catalyzed by copper monooxygenases such as peptidylglycine alpha-hydroxylating monooxygenase (PHM) and dopamine beta-monooxygenase (DbetaM). We investigated mononuclear copper(I) copper(II) complexes with bis[(6-neopentylamino-2-pyridyl)methyl][(2-pyridyl)methyl]amine (BNPA) functional models for these enzymes. The reaction of [Cu(II)(bnpa)]2+ H2O2, affords a quasi-stable copper(II)-hydroperoxo complex,...

A novel dinuclear zirconium sandwich-type silicotungstate cluster of [(gamma-SiW(10)O(36))(2)Zr(2)(mu-OH)(2)](10-) (1) was synthesized by the reaction a divacant lacunary gamma-Keggin [gamma-SiW(10)O(36)](8-) with ZrOCl(2).8H(2)O. The anion consisted two units sandwiching diamond Zr(2)(mu-OH)(2) core, and each atom in 1 six-coordinated to mu-OH ligands four oxygen atoms units. core reacted methanol give corresponding monomethoxo derivative [(gamma-SiW(10)O(36))(2)Zr(2)(mu-OH)(mu-OCH(3))](10-) (2).