Search results for "visual_art"

Inside Back Cover: Metal- and Reagent-Free Dehydrogenative Formal Benzyl-Aryl Cross-Coupling by Anodic Activation in 1,1,1,3,3,3-Hexafluoropropan-2-o…

2018

Cover Picture: Metal‐ and Reagent‐Free Highly Selective Anodic Cross‐Coupling Reaction of Phenols (Angew. Chem. Int. Ed. 20/2014)

2014

Direct Metal‐ and Reagent‐Free Sulfonylation of Phenols with Sodium Sulfinates by Electrosynthesis

2019

A novel electrochemical strategy for the synthesis of aryl sulfones by direct sulfonylation of phenols with sodium sulfinates has been developed. The C,S-coupling products are of particular interest for chemical synthesis, material sciences and pharmaceutical sciences. By using this metal- and reagent-free electrochemical method, aryl and diaryl sulfones can be obtained directly in good yields. The established one-step protocol is easy to perform, scalable, inherently safe, and enables a broad scope, which is not limited by quinoid-forming substrates.

Cover Feature: Direct Metal‐ and Reagent‐Free Sulfonylation of Phenols with Sodium Sulfinates by Electrosynthesis (Chem. Eur. J. 28/2019)

2019

Sustainable access to biobased biphenol epoxy resins by electrochemical dehydrogenative dimerization of eugenol

2019

Limited fossil resources require innovative monomers and polymers derived from renewable feedstocks such as plant biomass. Thermosetting epoxy resins largely rely on petrochemical bisphenol-type monomers, which give high performance materials but are controversial due to their effects on human health. Herein, we present two biobased epoxy resins by direct dehydrogenative dimerization of eugenol, the main component of clove oil. Taking the Principles of Green Chemistry into account, we developed electrochemical dehydrodimerization at reticulated vitreous carbon (RVC) electrodes using methanol as environmentally benign solvent. Thus, fluorinated solvents such as 1,1,1,3,3,3-hexafluoroisopropa…

Palladium Supported on Cross-Linked Imidazolium Network on Silica as Highly Sustainable Catalysts for the Suzuki Reaction under Flow Conditions

2013

Highly cross-linked imidazolium-based materials, obtained by radical oligomerization of bis-vinylimidazolium salts in the presence of 3-mercaptopropyl-modified silica gel, were used as supports for palladium catalysts. Thanks to the high imidazolium loading these materials were able to support a high amount of the metal (10 wt%). Such materials were characterized by several techniques (13C magic angle spinning nuclear magnetic resonance, the Brunauer-Emmett-Teller technique, X-ray photoelectron spectroscopy, and transmission electron microscopy). The palladium catalysts displayed good activity allowing the synthesis of several biphenyl compounds in high yields working with only 0.1 mol% of …

Phase equilibria modelling of kyanite-bearing anatectic paragneisses from the central Grenville Province

2008

Kyanite-bearing paragneisses from the Manicouagan Imbricate Zone and its footwall (high-P belt of the central Grenville Province) preserve evidence of partial melting with development of metamorphic textures involving biotite-garnet ± kyanite ± plagioclase ± K-feldspar-quartz. Garnet in these rocks displays a variety of zoning patterns with respect to Ca. Pseudosection modelling in the Na O-CaO-K O-FeO-MgO-Al O - SiO -H O-TiO -O (NCKFMASHTO) system using measured bulk rock compositions accounts for the textural evolution of two aluminous and two sub-aluminous samples from the presumed thermal peak to conditions at which retained melt solidified. The prograde features are best explained by p…

Successive alkalinity producing system for the treatment of acid sulphate soil runoff: preliminary results of a field trial

2005

A successive alkalinity producing system (SAPS) has been investigated as a potential passive treatment option for acid, metal containing runoff from acid sulphate soil. A pilot-scale system was installed at an agricultural land site in Rintala embankment area in mid-western Finland. The experimental layout consists of three parallel treatment units: two different SAPS cells and one limestone-filled cell for comparison of performance. The SAPS cells are composed of a bottom layer of limestone and a top layer of compost supplemented with sand. One of the SAPS cells contains sulphate-rich, waste gypsum mixed with the compost layer in order to enhance the metal reduction by sulphate reducing-ba…

Potential use of grapevine cv Askari for heavy metal phytoremediation purposes at greenhouse scale

2020

Grapevine varieties possess desirable characteristics for phytoremediation purposes. We investigated the potential of grapevine cv Askari in phytoremediation of heavy metal (HM) pollutions. In total 80 grapevine seedlings were exposed to four levels of HM stress (mild, low, moderate, and severe) in greenhouse condition during two growing years (2018 and 2019). The HM concentrations (Zn, Cu, Cd, Cr, and Pb) were subsequently determined in the soils, roots, and grapevine aboveground parts (AGPs), and then phytoextraction and phytostabilization potential assessment indices, i.e., biological absorption coefficient (BAC), bioconcentration factor (BCF), and translocation factor (TF), were calcula…

Major and trace elements in Boletus aereus and Clitopilus prunulus growing on volcanic and sedimentary soils of Sicily (Italy)

2017

The aim of this study was to determine and compare the content of 28 elements (Ag, Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sb, Se, Sr, Tl, U, V and Zn) in fruiting bodies of Boletus aereus Bull. and Clitopilus prunulus P. Kumm collected from eleven unpolluted sites of Sicily (Italy) and, also to relate the abundance of chemical elements in soil with their concentration in mushrooms. Median concentrations of the most abundant elements in Boletus aereus ranged from 31,290 μg/g (K) to 107 μg/g (Zn) in caps and from 24,009 μg/g (K) to 57 μg/g (Zn) in stalks with the following abundance order: K > Na > Ca > Mg > Fe > Al > Rb > Zn. The s…