Presence Of Other Functionalities Research Articles

Blue-LED activated photocatalytic hydrogenation of nitroarenes with Cu2O/CuO heterojunctions.

This study describes how the optimization of Cu2O/CuO heterostructures can enhance their (photo)catalytic performance. More specifically, the evaluation of catalysts with different Cu2O/CuO molar ratios was used to optimize their performance for the hydrogenation of 4-nitrophenol under both blue-LED light and dark conditions. For the first time, we analyzed the effect of blue LED irradiation on this reaction and found that when blue LEDs are used as the light source, a Cu2O/CuO ratio of 0.15 results in rate constants 7 to 3 times higher than those of catalysts with either lower (0.01) or higher (0.42) ratios. Furthermore, this photocatalyst shows good stability, >70% after 5 cycles, and excellent chemoselectivity in the selective reduction of the nitro group in the presence of other functionalities, i.e. -COOH, -CONH2 and -OH.

Flake-like glass nanoparticles reinforced natural polymeric scaffold as a promising substrate for bone regeneration

Natural polymeric scaffolds with unique characteristics can be considered as the best candidates for tissue engineering applications. But improve the mechanical properties of these scaffolds is a critical factor. In the current study glass nanoparticles with a flake-like morphology were used as filler in the chitosan-alginate scaffold. To understand the effect of surface modification, silane groups were created on these nanoparticles. SEM, FTIR, TGA, and XRD were used for scaffolds characterization. Swelling, degradation and mechanical trials are the other analyses to scaffold examination. Grafting of silane on nanoparticles was successful and the grafting ratio was 2.2 wt%. Pore shape and size were changed by using pure and modified nanoparticles. The swelling and degradation trend of the scaffold had a decreasing manner by applying nanoparticles. The polymeric scaffold compression modulus has improved 2.09 times. Our results show that, although glass nanoparticles with plate structure can make scaffolds with better mechanical features the presence of other functionalities on their surface is the appropriate means to gain better mechanical behavior.

Atom Efficient Preparation of Zinc Selenates for the Synthesis of Selenol Esters under "On Water" Conditions.

We describe here an atom efficient procedure to prepare selenol esters in good to excellent yields by reacting [(PhSe)2Zn] or [(PhSe)2Zn]TMEDA with acyl chlorides under “on water” conditions. The method is applicable to a series of aromatic and aliphatic acyl chlorides and tolerates the presence of other functionalities in the starting material.

En Route to a Practical Primary Alcohol Deoxygenation.

A long-standing scientific challenge in the field of alcohol deoxygenation has been direct catalytic sp(3) C-O defunctionalization with high selectivity and efficiency, in the presence of other functionalities, such as free hydroxyl groups and amines widely present in biological molecules. Previously, the selectivity issue had been only addressed by classic multistep deoxygenation strategies with stoichiometric reagents. Herein, we propose a catalytic late-transition-metal-catalyzed redox design, on the basis of dehydrogenation/Wolff-Kishner (WK) reduction, to simultaneously tackle the challenges regarding step economy and selectivity. The early development of our hypothesis focuses on an iridium-catalyzed process efficient mainly with activated alcohols, which dictates harsh reaction conditions and thus limits its synthetic utility. Later, a significant advancement has been made on aliphatic primary alcohol deoxygenation by employing a ruthenium complex, with good functional group tolerance and exclusive selectivity under practical reaction conditions. Its synthetic utility is further illustrated by excellent efficiency as well as complete chemo- and regio-selectivity in both simple and complex molecular settings. Mechanistic discussion is also included with experimental supports. Overall, our current method successfully addresses the aforementioned challenges in the pertinent field, providing a practical redox-based approach to the direct sp(3) C-O defunctionalization of aliphatic primary alcohols.

Study of UltraHigh Performance Supercritical Fluid Chromatography to measure free fatty acids with out fatty acid ester preparation.

Most lipids are best characterized by their fatty acids which may differ in (a) chain length, (b) degree of unsaturation, (c) configuration and position of the double bonds, and (d) the presence of other functionalities. Thus, a fast, simple, and quantitative analytical technique to determine naturally occurring free fatty acids (FFA) in different samples is very important. Just as for saponified acylglycerols, the determination of FFA's has generally been carried out by high resolution gas chromatography (HRGC). The use of an open tubular capillary column coupled with a flame ionization or mass spectrometric detector provides for both high resolution and quantification of FFA's but only after conversion of all free fatty acids to fatty acid methyl esters (FAME) or pentafluorobenzyl esters. Unfortunately, volatilization of labile ester derivatives of mono- and poly-unsaturated FFA's can cause both thermal degradation and isomerization of the fatty acid during HRGC. The employment of a second generation instrument (here referred to as UltraHigh Performance Supercritical Fluid Chromatograph, UHPSFC) with high precision for modified flow and repeated back pressure adjustment in conjunction with sub-2μm various bonded silica particles (coupled with evaporative light scattering, ELSD, and mass spectrometric, MS, detection) for separation and detection of the following mixtures is described: (a) 31 free fatty acids, (b) isomeric FFA's, and (c) lipophilic materials in two real world fish oil samples. Limits of detection for FFA's via UHPSFC/MS and UHPSFC/ELSD versus detection of FAME's via HRGC/MS are quantitatively compared.

Identification of the Sulfone Functionality in Protonated Analytes via Ion/Molecule Reactions in a Linear Quadrupole Ion Trap Mass Spectrometer

A tandem mass spectrometric method is presented for the rapid identification of drug metabolites that contain the sulfone functional group. This method is based on a gas-phase ion/molecule reaction of protonated sulfone analytes with trimethyl borate (TMB) that yields a diagnostic product ion, adduct-Me2O, at high reaction efficiency. A variety of compounds with different functional groups, such as sulfoxides, hydroxylamines, N-oxides, anilines, phenol, an aliphatic amine, and an aliphatic alcohol, were examined to probe the selectivity of this reaction. Except for protonated sulfones, most of the protonated compounds react very slowly or not at all with TMB. Most importantly, none of them give the adduct-Me2O product. A mechanism that explains the observed selectivity is proposed for the diagnostic reaction and is supported by quantum chemical calculations. The reaction was tested with the anti-inflammatory drug sulindac and its metabolite, sulindac sulfone, which were readily distinguished. The presence of other functionalities in addition to sulfone was found not to influence the diagnostic reactivity.

Novel Heterobimetallic Radiotheranostic: Preparation, Activity, and Biodistribution

A novel Ru(II) (arene) theranostic complex is presented. It is based on a 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid macrocycle bearing a triarylphosphine and can be tracked in vivo by using the γ emission of (153) Sm atoms. Notably, the heteroditopic ligand can be selectively metalated with ruthenium at the phosphorus atom despite the presence of other functionalities that are prone to metal coordination. Subsequent labeling with radionuclides such as (153) Sm can then be performed easily. The resulting heterobimetallic complex exhibits favorable solubility and stability properties in biologically relevant media. It also shows in vitro cytotoxicity in line with that expected for this type of metallodrug, and is nontoxic to the organism as a whole. As a proof of concept, initial studies in healthy mice were performed to obtain information about the uptake, biodistribution, and excretion of the radiolabeled complex.

ChemInform Abstract: Homoleptic Ruthenium(III) Chalcogenolates: A Single Precursor to Metal Chalcogenide Nanoparticles Catalyst.

AbstractNanocrystalline RuSe2, obtained by pyrolysis of a [Ru(SePh)3] polymer, catalyzes the selective reduction of nitrobenzenes (I) in the presence of other functionalities.

Homoleptic ruthenium(iii) chalcogenolates: a single precursor to metal chalcogenide nanoparticles catalyst

Eight homoleptic metal(III) arylchalcogenolate polymers [M(EPh-p-X)(3)](n) (M = Ru, Cr, and Mo) were characterized by PXRD. Structural solution of [Ru(SPh-p-tBu)(3)](n)1 was achieved by Rietveld refinement of the PXRD data. Pyrolysis of [Ru(SePh)(3)](n)4 produced nanostructured RuSe(2), which selectively catalyzed the reduction of nitro compounds in the presence of other functionalities.

Triboluminescence of spicules of hexactinellid sponges

325 Organosilicon spicules of hexactinellid sponges possess unique physical and chemical properties and, therefore, they attract the attention of experts of vari ous specialties: biologists, physicists, chemists, and materiologists [1–5]. The principal function of spi cules of hexactinellids is certainly a skeletal one. Still, their organizational traits imply presence of other functions. In particular, a hypothesis was suggested that these spicules perform the function analogous to that of the nervous system. The spicules may serve as waveguides transmitting optical, electric, or chemical signals and carry information on the state of the envi ronment to cells within a sponge [6].

ChemInform Abstract: Novel Routes for the Synthesis of Upper Rim Amino and Methoxycarbonyl Functionalized Calix(4)arenes Carrying Other Types of Functional Groups.

The selective functionalization of calix[4]arenes 1 by iodination at the upper rim in the presence of other functionalities is described. The resulting (partly) iodinated calix[4]arenes 2 are good starting materials for the preparation of both the corresponding carboxylic ester and amino derivatives 3 and 6, respectively.

Space for people, plants, and livestock? Quantifying interactions among multiple landscape functions in a Dutch rural region

Rural landscapes are often multifunctional, meaning that at one single location different goods and services are being provided. Multifunctionality is spatially heterogeneous as not all areas are equally suitable to supply multiple goods and services. This suitability depends on favourable biophysical and socio-economic conditions and interactions among landscape functions. The objective of this paper is to identify and quantify interactions among landscape functions in a diverse and dynamic rural region, the Gelderse Vallei in the Netherlands. To be able to study these interactions first seven landscape functions (residential, intensive livestock, cultural heritage, tourism, plant habitat, arable production, and leisure cycling) are quantified and mapped using landscape indicators. These landscape function maps are subsequently aggregated to identify and quantify multifunctionality. The results of these analyses are used to study three aspects of landscape function interactions (a) influence of landscape characteristics on function interactions, (b) interrelations among landscape functions and (c) effect of multifunctionality on the different landscape functions. Landscape functions do not equally interact with one another, some landscape functions are affected negatively by the presence of other functions while other landscape functions benefit from multifunctionality. At multifunctionality hot spots different landscape functions are present that are enhancing one another. Additionally, in our study area it appears that mainly locations with landscape functions that sub-optimally provide goods and services are strongly multifunctional. Quantification and an improved understanding of landscape interactions will help to design and evaluate spatial policies related to the provision of multiple goods and services by the landscape.

The First Conversion of Primary Alkyl Halides to Nitroalkanes under Aqueous Medium.

AbstractFor Abstract see ChemInform Abstract in Full Text.

The first conversion of primary alkyl halides to nitroalkanes under aqueous medium.

Primary nitroalkanes and alpha,omega-dinitroalkanes can be easily obtained in aqueous medium by reaction of the corresponding halo derivatives with silver nitrite. The procedure works well with both alkyl bomide and alkyl iodide and proceeds in satisfactory to good yields even in the presence of other functionalities, minimizing the formation of the undesired alkyl nitrites.

Analytical methods and steps to sample preparation for determination of molecular species of fatty acids.

The generation of the lipid-signal molecules diacylglycerol (DAG) and phosphatidic acid (PA) from phospholipids like phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylinositols (PIs) has been implicated in the transduction events essential for proliferation and differentiation in many cells. If the DAG or PA produced by cells is being generated by hydrolysis of a given phospholipid, then the fatty acid molecular species (MSFA) profile of the lipid-signal molecule should be nearly identical to that of the hydrolyzed phospholipid. Therefore, it is possible to find the source of stimulated DAG or PA by comparing the molecular species profile of the cellular DAGs or PAs to those of parent phospholipids (,). Lipids can be characterized by their fatty acids that differ in chain length, degree of unsaturation, configuration, and position of the double bonds, and the presence of other functionalities (see Note 1). High-performance liquid chromatography (HPLC) methods have been developed and are now routinely used to resolve most of the molecular species, either with or without derivatization. The nonderivatized HPLC procedures are fast and simple but relatively large amounts of lipids are required and the resolution is sometimes questionable. The derivatized HPLC procedures are more complex, but have a good resolution and are essential when diacyl, alkylacyl, and alkenylacyl subclasses have to be separated.

Halide Exchange: Preparation of Alkyl Chlorides

Abstract Primary alkyl bromides can be quantitatively converted into the corresponding chlorides under very mild reaction conditions. The neutral conditions required for such bromide displacements allow the presence of other functions on the substrate.

Fatty acid profiles of lipid samples.

Most lipids are best characterized by their fatty acids which differ in chain length, the degree of unsaturation, configuration and position of the double bonds, and the presence of other functionalities. The fatty acid profiles are currently most frequently determined by capillary gas chromatography of the methyl esters which are prepared by a variety of methods. These are discussed with an emphasis on more recent developments, along with the stationary phases used for the separations and the methods employed for identification of the fatty acids. HPLC is applied less frequently for ascertaining fatty acid profiles than GC, but a very large number of derivatives for ultraviolet and fluorescence detection have been proposed. This method continues to evoke increasing interest, particularly in conjunction with fluorescence detection. This technique enables attainment of greater sensitivities than with standard GC methods employing flame ionization detection. Extensive applications of it to the analysis of free fatty acids in blood and other biomedical samples are clearly discernible. Other methods, including supercritical fluid chromatography, have found only limited application for fatty acid profiling.

Novel Routes for the Synthesis of Upper Rim Amino and Methoxycarbonyl Functionalized Calix[4]arenes Carrying Other Types of Functional Groups

The selective functionalization of calix[4]arenes 1 by iodination at the upper rim in the presence of other functionalities is described. The resulting (partly) iodinated calix[4]arenes 2 are good starting materials for the preparation of both the corresponding carboxylic ester and amino derivatives 3 and 6, respectively.

Solvent effects in NMR spectroscopy—III : Chemical shifts induced by benzene in ketones

Proton chemical shifts determined in deuterochloroform and benzene solutions for a large number of ketones are consistent with the formation of a collision complex between carbonyl groups and benzene solvent molecules. The solvent shifts (Δ = δ CDCl 3 − δ C 6H 6 ) associated with carbonyl groups frequently remain dominant even in the presence of other functionalities and are approximately additive. As a general rule, Δ values are negative for protons lying in front of the carbonyl group and positive for protons lying behind the carbonyl group. Solvent shifts are therefore useful in establishing the spatial relationships between ketones and protons whose resonances can be discerned in both solvents. The preferred orientation of the 17β-acetyl group in 5α-pregnan-20-one has been deduced from solvent shifts.