Uniform wrapping of copper(I) oxide nanocubes by self-controlled copper-catalyzed azide-alkyne cycloaddition toward selective carbon dioxide electrocatalysis.

Copper(I) oxide nanocubes were wrapped with an extremely uniform organic layer grown by self-controlled, Cu-mediated catalysis. This layer aided in retaining the initial cubic structure of the copper nanocubes during their use as a CO reduction electrocatalyst, resulting in high CO reduction selectivity by strong suppression of hydrogen evolution because of exclusion of water from the surface.

The [AgCuHBr(CCPh)(PPh)] : AgH silver hydride core protected by [CuAg(CCPh)(PPh)] motifs.

Copper alkynyl complexes [CuAg3(C[triple bond, length as m-dash]CAr)3(PPh3)3]+ (Ar = Ph, p-C6H4Me), in which three Ag(PPh3) units are bound among three C[triple bond, length as m-dash]CAr arms of trigonal-planar [Cu(C[triple bond, length as m-dash]CAr)3]2-, were selected as a protecting unit to cover the metal core of an atomically precise core-shell-type cluster. First, the formation of the protecting unit through the reaction of Cu(NCMe)4(PF6) with Ag(C[triple bond, length as m-dash]CAr) and PPh3 in a 1 : 3 : 3 ratio was confirmed. The reaction gave dimeric [CuAg3(C[triple bond, length as m-dash]CAr)3(PPh3)3]22+, in which the two planar [CuAg3(C[triple bond, length as m-dash]CAr)3(PPh3)3]+ units were stacked.

On-Surface Modification of Copper Cathodes by Copper(I)-Catalyzed Azide Alkyne Cycloaddition and CO Reduction in Organic Environments.

In this study, organic structures were introduced onto copper cathodes to induce changes in their electrocatalytic CO reduction activity. Poorly soluble organic polymers were distributed onto the copper surface as a thin layer by polymerizing monomeric precursors a copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) activated by anodization of the copper substrate. The resulting structure possesses copper surface atoms that are available to participate in the CO reduction reaction-comparable to close-contact organic structures-and stabilize the adsorption of organic layers through the CO reduction process.

Protonation and electrochemical properties of a bisphosphide diiron hexacarbonyl complex bearing amino groups on the phosphide bridge.

A bisphosphide-bridged diiron hexacarbonyl complex 3 with NEt2 groups on the phosphide bridge was synthesized to examine a new proton relay system from the NEt2 group to the bridging hydride between the two iron centers. As a precursor of the bridging moiety, peri-Et2NP-PNEt2-bridged naphthylene 5 was synthesized by the reaction of 1,8-dilithionaphthylene with two equivalents of Cl2PNEt2 followed by reductive P-P bond formation by magnesium. The reaction of the diphosphine ligand 5 with Fe2(CO)9 gave the diiron hexacarbonyl complex 3, in which the P-P bond of the ligand was cleaved to form the bisphosphide-bridge.

Eudesmane-type sesquiterpene glycosides: sonneratiosides A-E and eudesmol β-D-glucopyranoside from the leaves of Sonneratia alba.

Five eudesmane-type sesquiterpene glycosides, named sonneratiosides A-E (1-5), were isolated from the leaves of Sonneratia alba (Lythraceae). The aglycone of sonneratioside A was identified as cryptomeridiol also known as proximadiol. X-ray crystallographic analysis of sonneratioside A confirmed its structure and its absolute stereochemistry.

Novel chloride-centered Ag clusters featuring a cuboctahedral Ag skeleton.

Two novel chloride-centered Ag clusters with the same framework but different supporting phosphines are synthesized by the reaction of PhC[triple bond, length as m-dash]CAg, AgSbF, PPh (or P(p-Tol)), and NaBH in CHCl, followed by the addition of PhC[triple bond, length as m-dash]CH and NEt. The inner twelve Ag atoms of these two clusters are arranged in a rare cuboctahedral structure, which can be rationalized by considering a ligand effect. Through careful analysis, we find that the central chloride arises from a generally ignored but nonetheless existing reaction between CHCl and NEt, which is well recognized as the Menshutkin reaction.

An Alkynyl-Stabilized Pt Ag Cluster Featuring a Two-Dimensional Alkynyl-Platinum "Crucifix Motif".

The "staple motif" has been widely applied to depict and predict the structures of thiolate or alkynyl-protected gold nanoclusters. By contrast, the composition, dimensions, configuration, and functionality of the platinum-ligand motif has remained completely unknown. Herein, we report the synthesis and crystal structure of a novel luminescent Pt Ag (C≡CPh) (1) cluster, in which two-dimensional and two-functional alkynyl-platinum "crucifix motif" was observed.

An Atomically Precise Alkynyl-Protected PtAg Superatom Nanocluster and Its Structural Implications.

The synthesis and structure determination of an alkynyl-protected Pt-doped Ag superatom nanocluster, [PtAg (C≡CC H CH ) ](SbF )  (1), are reported. The metallic core of this cluster can be viewed as a concentric three-shell Russian doll comprising Pt@Ag @Ag , in which the missing icosidodecahedral Ag shell and a new structural unit, M , have been observed. On the surface of 1, 28 alkynyl groups and 4 SbF anions were found co-protecting it.

Synthesis and coordination chemistry of (PNEt)-bridged [2]ferrocenophanes.

The trivalent phosphorus-bridged [2]ferrocenophane complex 2 having NEt groups on the respective phosphorus centers was prepared, and its reactions as a diphosphine ligand were examined for iron and chromium carbonyl complexes. Both the phosphorus centers of 2 coordinated to Fe(CO) fragments to form (μ-2)-[Fe(CO)], while the bulkier Cr(CO) fragment formed only a monochromium complex [Cr(κ-2)(CO)]. Dissociation of CO from [Cr(κ-2)(CO)] changed the coordination mode of 2 from κ to κ to form [Cr(κ-2)(CO)] having a three-membered ring.

Structure elucidation of secondary metabolites isolated from the leaves of Ixora undulate and their inhibitory activity toward advanced glycation end-products formation.

Three aromatic glycosides (1-3), two sulfur and nitrogen-containing compound glucosides (4, 5), and one flavonoid glycoside (6) were isolated from the leaves of Ixora undulata. Their structures were established by extensive 1D, 2D NMR, and HRESIMS experiments, and structure 4 was further confirmed by single crystal X-ray diffraction analysis. Of the assayed compounds, 7, 11 and 12 showed strong inhibitory activity toward advanced glycation end-products formation with IC50 values of 86.

Preparation and redox studies of α1- and α2-isomers of mono-Ru-substituted Dawson-type phosphotungstates with a DMSO ligand: [α1/α2-P2W17O61Ru(II)(DMSO)](8-).

Both α1- and α2-isomers of mono-Ru-substituted Dawson-type heteropolytungstates with a DMSO ligand, [α1-P2W17O61Ru(II)(DMSO)](8-) and [α2-P2W17O61Ru(II)(DMSO)](8-), are prepared from the α2-isomer of a monolacunary derivative, [α2-P2W17O61](10-). Reaction of [α2-P2W17O61](10-) with Ru(DMSO)4Cl2 under hydrothermal conditions produces [α2-P2W17O61Ru(II)(DMSO)](8-) as a main product together with [α1-P2W17O61Ru(II)(DMSO)](8-), [PW11O39Ru(II)(DMSO)](5-), and [P2W18O62](6-) as byproducts. By addition of KCl to the reaction mixture, K8[α2-P2W17O61Ru(II)(DMSO)] is isolated in a moderate yield.

Kinetic stabilization and reactivity of π single-bonded species: effect of the alkoxy group on the lifetime of singlet 2,2-dialkoxy-1,3-diphenyloctahydropentalene-1,3-diyls.

Kinetic stabilization and reactivity of π single-bonded species have been investigated in detail by generating a series of singlet 2,2-dialkoxy-1,3-diphenyloctahydropentalene-1,3-diyls (DRs). The lifetime at 293 K in benzene was found to increase when the carbon chain length of the alkoxy groups was increased; 292 ns (DRb; OR = OR' = OCH3) <880 ns (DRc; OR = OR' = OC2H5) <1899 ns (DRd; OR = OR' = OC3H7) ≈2292 ns (DRe; OR = OR' = OC6H13) ≈2146 ns (DRf; OR = OR' = OC10H21). DRh (OR = OC3H7, OR' = OCH3; 935 ns) with the mixed-acetal moiety is a longer-lived species than another diastereomer DRg (OR = OCH3, OR' = OC3H7; 516 ns).

Modified synthesis and supramolecular polymerization of rim-to-rim connected bisresorcinarenes.

The acid-catalyzed condensation reaction of resorcinol and bisdimethoxyacetals gave rise to rim-to-rim connected bisresorcinarenes in good yields. In the presence of ethanol, the homoditopic bisresorcinarenes assembled to form supramolecular polymers via hydrogen bonding interactions. The fibrous morphologies of the supramolecular polymers were confirmed by atomic force microscopy and scanning electron microscopy.

Formation of macrocyclic lactones in the Paternò-Büchi dimerization reaction.

Furan-2-ylmethyl 2-oxoacetates 1a,b, in which the furan ring and the carbonyl moiety were embedded intramolecularly, were synthesized from commercially available furan-2-ylmethanol and their photochemical reaction (hν > 290 nm) was investigated. Twelve-membered macrocyclic lactones 2a,b with C(i) symmetry including two oxetane-rings, which are the Paternò-Büchi dimerization products, were isolated in ca. 20% yield.

Synthesis of binuclear complexes bound in an enlarged tetraphosphamacrocycle: two diphosphine metal units linked in front-to-front style.

A large-hole tetraphosphamacrocycle 2, with four phosphorus centers separated at the corners of a 3.7 A wide and 9.7 A long rectangle, was synthesized by a stepwise cyclization reaction between PCl-bridged [1.

Cobalt-catalyzed trimethylsilylmethylmagnesium-promoted radical alkenylation of alkyl halides: a complement to the Heck reaction.

A cobalt complex, [CoCl2(dpph)] (DPPH = [1,6-bis(diphenylphosphino)hexane]), catalyzes an intermolecular styrylation reaction of alkyl halides in the presence of Me3SiCH2MgCl in ether to yield beta-alkylstyrenes. A variety of alkyl halides including alkyl chlorides can participate in the styrylation. A radical mechanism is strongly suggested for the styrylation reaction.

Ring-opening reaction of phosphorus-bridged [1]ferrocenophane via ring slippage from eta(5)- to eta(1)-Cp.

A reaction mechanism was investigated for a ring-opening reaction of RP(E)-bridged [1]ferrocenophane, where RP(E) = PhP(S) (3a), PhP (3b), and MesP (3c) (Mes = 2,4,6-trimethylphenyl). Irradiation of UV-vis light in the presence of an excess amount of P(OMe)(3) transformed 3a to [Fe(PhP(S)(eta(5)-C(5)H(4))(eta(1)-C(5)H(4)))(P(OMe)(3))(2)] (4a), in which one of the two cyclopentadienyl (Cp) rings of 3a changed its coordination mode from eta(5) to eta(1) and vacant coordination sites thus formed on the iron center were occupied by two P(OMe)(3) ligands. The molecular structure of 4a was determined by X-ray analysis, in which eta(1)-Cp adopted a 1-Fe-2-P-1,3-cyclopentadiene structure.