Effect of Nitrogen on the Structure and Composition of Primordial Organic Matter Analogs.

Organic molecules are ubiquitous in primitive solar system bodies such as comets and asteroids. These primordial organic compounds may have formed in the interstellar medium and in protoplanetary disks (PPDs) before being accreted and further transformed in the parent bodies of meteorites, icy moons, and dwarf planets. The present study describes the composition of primordial organics analogs produced in a laboratory simulator of the PPD (the Nebulotron experiment at the CRPG laboratory) with nitrogen contents varying from N/C < 0.

Fifty Shades of Phenanthroline: Synthesis Strategies to Functionalize 1,10-Phenanthroline in All Positions.

1,10-Phenanthroline (phen) is one of the most popular ligands ever used in coordination chemistry due to its strong affinity for a wide range of metals with various oxidation states. Its polyaromatic structure provides robustness and rigidity, leading to intriguing features in numerous fields (luminescent coordination scaffolds, catalysis, supramolecular chemistry, sensors, theranostics, etc.).

Copper(I) Bis(diimine) Complexes with High Photooxidation Power: Reductive Quenching of the Excited State with a Benzimidazoline Sacrificial Donor.

The reductive quenching of photoexcited photosensitizers is a very efficient way to achieve challenging reduction reactions. In this process, the excited photosensitizer is reduced by a sacrificial electron donor. This mechanism is rarely observed with copper(I) bis(diimine) complexes, which are nevertheless acknowledged as very promising photosensitizers.

Investigation of copper oxidation states in plasmonic nanomaterials by XAS and Raman spectroscopy.

Plasmonic core-shell-isolated nanoparticles are promising nanoplatforms for photocatalysis and for low detection analysis. This paper describes the characterization of a 2,2'-bipyridine phosphonate functionalized Ag@TiO nanocomposite which complexes copper ions by enhanced Raman spectroscopy and X-ray absorption (XANES and EXAFS). We distinguished Cu(i) from Cu(ii) complexes using shell-isolated nanoparticle enhanced Raman (SHINERS) combined with XAS spectroscopy.

Surface modification of plasmonic noble metal-metal oxide core-shell nanoparticles.

A comprehensive survey on the methods for the surface modification of plasmonic noble metal-metal oxide core-shell nanoparticles is presented. The review highlights various strategies for covalent attachment and electrostatic binding of molecules and molecular ions to core-shell nanoparticles with a focus on plasmonically active silver and gold nanoparticles encapsulated by SiO and TiO shells.

Functionalized core-shell Ag@TiO nanoparticles for enhanced Raman spectroscopy: a sensitive detection method for Cu(ii) ions.

This paper demonstrates the use of surface plasmon resonance of core-shell Ag@TiO2 particles in SHINERS experiments. A copper(ii) complex grafted onto Ag@TiO2 surface was probed by Raman spectroscopy using resonance excitation profiles vs. excitation wavelengths (514, 633 and 785 nm) to tune the Raman signals.

Non-photochemical catalytic hydrolysis of methyl parathion using core-shell Ag@TiO nanoparticles.

Highly water-dispersible core-shell Ag@TiO nanoparticles were prepared and shown to be catalytically active for the rapid degradation of the organothiophosphate pesticide methyl parathion (MeP). Formation of the hydrolysis product, -nitrophenolate was monitored at pH 7.5 and 8.

Phosphonate-Mediated Immobilization of Rhodium/Bipyridine Hydrogenation Catalysts.

RhL complexes of phosphonate-derivatized 2,2'-bipyridine (bpy) ligands L were immobilized on titanium oxide particles generated in situ. Depending on the structure of the bipy ligand-number of tethers (1 or 2) to which the phosphonate end groups are attached and their location on the 2,2'-bipyridine backbone (4,4'-, 5,5'-, or 6,6'-positions)-the resulting supported catalysts showed comparable chemoselectivity but different kinetics for the hydrogenation of 6-methyl-5-hepten-2-one under hydrogen pressure. Characterization of the six supported catalysts suggested that the intrinsic geometry of each of the phosphonate-derivatized 2,2'-bipyridines leads to supported catalysts with different microstructures and different arrangements of the RhL species at the surface of the solid, which thereby affect their reactivity.

Visible light assisted hydrogen generation from complete decomposition of hydrous hydrazine using rhodium modified TiO photocatalysts.

Hydrogen is considered to be an ideal energy carrier, which produces only water when combined with oxygen and thus has no detrimental effect on the environment. While the catalytic decomposition of hydrous hydrazine for the production of hydrogen is well explored, little is known about its photocatalytic decomposition. The present paper describes a highly efficient photochemical methodology for the production of hydrogen through the decomposition of aqueous hydrazine using titanium dioxide nanoparticles modified with a Rh(i) coordinated catechol phosphane ligand (TiO-Rh) as a photocatalyst under visible light irradiation.

Comparison of Zirconium Phosphonate-Modified Surfaces for Immobilizing Phosphopeptides and Phosphate-Tagged Proteins.

Different routes for preparing zirconium phosphonate-modified surfaces for immobilizing biomolecular probes are compared. Two chemical-modification approaches were explored to form self-assembled monolayers on commercially available primary amine-functionalized slides, and the resulting surfaces were compared to well-characterized zirconium phosphonate monolayer-modified supports prepared using Langmuir-Blodgett methods. When using POCl3 as the amine phosphorylating agent followed by treatment with zirconyl chloride, the result was not a zirconium-phosphonate monolayer, as commonly assumed in the literature, but rather the process gives adsorbed zirconium oxide/hydroxide species and to a lower extent adsorbed zirconium phosphate and/or phosphonate.

Design and optimization of a phosphopeptide anchor for specific immobilization of a capture protein on zirconium phosphonate modified supports.

The attachment of affinity proteins onto zirconium phosphonate coated glass slides was investigated by fusing a short phosphorylated peptide sequence at one extremity to enable selective bonding to the active surface via the formation of zirconium phosphate coordinate covalent bonds. In a model study, the binding of short peptides containing zero to four phosphorylated serine units and a biotin end-group was assessed by surface plasmon resonance-enhanced ellipsometry (SPREE) as well as in a microarray format using fluorescence detection of AlexaFluor 647-labeled streptavidin. Significant binding to the zirconated surface was only observed in the case of the phosphopeptides, with the best performance, as judged by streptavidin capture, observed for peptides with three or four phosphorylation sites and when spotted at pH 3.

Facile P,N-heterocycle synthesis via tandem aminomethylation-cyclization of H-phosphinate building blocks.

Various heterocycles containing phosphorus and nitrogen are easily synthesized from readily available H-phosphinate building blocks. Aminomethylation of these H-phosphinates is followed by in situ cyclization through substitution or cross-coupling to produce novel heterocycles in moderate to good yields.

Synthesis of P,N-heterocycles from omega-amino-H-phosphinates: conformationally restricted alpha-amino acid analogs.

P,N-heterocycles (3-hydroxy-1,3-azaphospholane and 3-hydroxy-1,3-azaphosphorinane-3-oxide) are synthesized in moderate yield from readily available omega-amino-H-phosphinates and aldehydes or ketones via an intramolecular Kabachnik-Fields reaction. The products are conformationally restricted phosphinic analogs of alpha-amino acids. The multigram-scale syntheses of the H2N(CH2)(n)PO2H2 phosphinic precursors (n = 1, 2, 3) and some derivatives are also described.

Synthesis and antiviral properties of some polyphenols related to Salvia genus.

An efficient synthesis of the acid part of salvianolic acid E 2 is described. Compound 2 was obtained from vanillin in 10 steps and 21% overall yield. During the synthesis of 2 an unexpected 5-oxo-4b,9b-dihydroindano[1,2-b]benzofuran rac-12 was isolated.

The total synthesis of fukiic acid, an HIV-1 integrase inhibitor.

A successful synthesis of fukiic acid is described in 7% overall yield (6 steps from veratraldehyde). rac-Fukiic acid was found to be a potent inhibitor of HIV-1 integrase but did not reveal any antiviral activity in the MT-4 cells assay.

Synthesis and biological activities of a series of 4,5-diaryl-3-hydroxy-2(5H)-furanones.

A series of thirteen 4,5-diaryl-3-hydroxy-2(5H)-furanones were synthesized. They were evaluated for their antioxidant potencies and inhibitory properties of 5-lipoxygenase, cyclooxygenases, HIV-1 integrase and PC3 cell proliferation. New hits were discovered either in the anti-proliferation test or in the HIV anti-integrase test.

Synthesis and HIV-1 integrase inhibitory activities of caffeic acid dimers derived from Salvia officinalis.

The synthesis of two caffeoyl-coumarin conjugates, derived from sagecoumarin, has been accomplished, starting from ferulic acid, isoferulic acid and sesamol. Both compounds exhibited potent inhibitory activities at micromolar concentrations against HIV-1 integrase in 3'-end processing reaction but were less effective against HIV-1 replication in a single-round infection assay of HeLa-beta-gal-CD4+ cells.