Fully bio- and CO2-sourced non-isocyanate polyurethanes (NIPUs) were synthesized by reaction of carbonated soybean oil (CSBO) either with biobased short diamines or amino-telechelic oligoamides derived from fatty acids to achieve respectively thermoset thermoplastic NIPUs. Biobased vegetable oils first obtained metal-free coupling reactions CO2 epoxidized under supercritical conditions (120 °C, 100 bar) before complete characterization FTIR, 1H NMR, electrospray ionization mass spectroscopy...

To avoid predation, holothuroids produce feeding-deterrent molecules in their body wall and viscera, the so-called saponins. Five tropical sea cucumber species of family Holothuriidae were investigated order to study saponin content two different organs, Cuvierian tubules. Mass spectrometry techniques (MALDI- ESI-MS) used detect analyze The smallest number saponins was observed Holothuria atra, which contained a total four congeners, followed by leucospilota, Pearsonothuria graeffei...

Volatile impurities contained in polyethyleneimine (PEI), and identified as ethyleneimine dimers trimers, are reported. These N-based molecules show a strong reducing character, demonstrated by the change electrical conductivity of organic (semi)conductors exposed to PEI vapor. The results prove that electron transfer rather than dipole effect at electrode interface is origin work-function modification PEI-based layers. As service our authors readers, this journal provides supporting...

Despite offering robust mechanical properties, polymer networks suffer from a lack of recyclability, reshaping, and healability. Designing stiff remendable that can repair under mild conditions remains challenge to extend their field applications. Herein, we describe simple approach design nonisocyanate-based polyurethane network featuring multiresponsiveness (to humidity temperature) outstanding healing as obtained by combining iminoboronate boroxine chemistry. In spite the presence...

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication the EditorNEXTIncorporation of Different End Groups in Conjugated Polymers Using Functional Nickel InitiatorsAlfons Smeets†, Karlien Van den Bergh†, Julien De Winter‡, Pascal Gerbaux‡, Thierry Verbiest†, and Guy Koeckelberghs*†View Author Information† Laboratory Molecular Electronics Photonics, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium‡ Mass Spectrometry Center, Organic Chemistry...

Shape-memory polymers (SMPs) are a class of stimuli-responsive materials that have attracted tremendous attention in various applications, especially the medical field. While most SMPs thermally actuated, relating to change thermal transition (e.g., melting temperature), can be actuated upon exposure light emerging. Recently, there has been new interest into multiple order cover range applications for these smart materials. In this work, poly(ester-urethane)s (PURs) made heating-responsive...

Developing intrinsic self-healing polymeric materials is of great interest nowadays to extend material lifetime and/or prevent the replacement damaged pieces. Spontaneously humidity-sensitive healable polymer network built around dynamic covalent B-O bonds was templated by using iminoboronate-based boroxine derivatives. Taking advantage boroxine/boronic acid equilibrium and iminoboronate chemistry, it possible construct able self-heal without requiring any energy-demanding external...

Excessive pollen harvesting by bees can compromise the reproductive success of plants. Plants have therefore evolved different morphological structures and floral cues to narrow spectrum feeding visitors. Among "filtering" mechanisms, chemical mechanical protection might shape bee-flower interactions restrict exploitation a specific suite visitors such as observed in Asteraceae. Asteraceae is indeed only occasionally exploited generalist bee species but plentifully foraged specialist ones...

SUMMARY More than 100 triterpene glycosides (saponins) have been characterized in holothuroids the past several decades. In particular, Holothuria forskali contains 26 saponins its Cuvierian tubules and 12 body wall. This high diversity could be linked to a chemical defense mechanism, most commonly accepted biological role for these secondary metabolites. We performed an integrated study of body-wall H. forskali. The are mainly localized epidermis mesothelium wall appear released when...

Polythiophenes with alcohol, tosylate, azide, ethynylene, carboxylic acid, and amine end groups were prepared by a combination of functionalized nickel initiators postpolymerization reactions. The azide ethynylene polymers subsequently used in click reaction to produce conjugated block copolymer. Finally, triblock-copolymer was synthesized means chain growth polymerization initiated binuclear initiator.

Abstract Nowadays, numerous experimental and theoretical studies are devoted to the research field of polythiophenes other electroconjugated polymers due huge potentialities those conducting polymers. Synthetic procedures now developed reach highest control over both polymerization analytical methodologies allowing an in‐depth straightforward characterization polymer samples without any required doubt. Mass spectrometry in particular MALDI‐ToF measurements definitively suitable meet...

Spinochromes are principally known to be involved in sea urchin pigmentation as well for their potentially interesting pharmacological properties. To assess biological role physiology, experiments undertaken on crude extracts from four species and isolated spinochromes order test antibacterial, antioxidant, inflammatory cytotoxic activities. First, the antibacterial assays show that use of representatives effects inaccurate. The purified showed a decrease growth strains with an intensity...

Abstract Marine organisms have developed a high diversity of chemical defences in order to avoid predators and parasites. In sea cucumbers, saponins function as repellents many species produce these cytotoxic secondary metabolites. Nonetheless, they are colonized by numerous symbiotic amongst which the Harlequin crab, Lissocarcinus orbicularis , is one most familiar Indo-Pacific Ocean. We here identify for first time nature molecules secreted cucumbers attracting symbionts: kairomones...

Abstract The organocatalytic coupling of CO 2 with oxetanes is investigated under solvent‐free conditions. influence the main reaction parameters (type system, pressure, and temperature) on yield, product formed, selectivity are discussed. An onium salt combined a fluorinated alcohol promotes efficient selective synthesis α,ω‐hydroxyl oligocarbonates by at 130 °C pressure as low MPa. NMR characterizations were correlated matrix‐assisted laser desorption/ionization time‐of‐flight mass...

We report a novel class of star-shaped multiazobenzene photoswitches comprising individual photochromes connected to central trisubstituted 1,3,5-benzene core. The unique design such C3-symmetric molecules, consisting conformationally rigid and pseudoplanar scaffolds, made it possible explore the role electronic decoupling in isomerization azobenzene units. our tris-, bis-, mono(azobenzene) compounds limits π-conjugation between switches belonging same molecule, thus enabling efficient...

Abstract Current evidence suggests that pollen is both chemically and structurally protected. Despite increasing interest in studying bee–flower networks, the constraints for bee development related to nutritional content, toxicity digestibility as well their role shaping of interactions have been poorly studied. In this study we combined bioassays generalist Bombus terrestris on Cirsium , Trifolium Salix Cistus genera with an assessment toxicity, pollen. Microcolonies showed significant...

Artificial enzymes based on polystyrene copolymers featuring a metal complex within their structure, so-called Single Chain Nanoparticles (SCNPs), are currently discussed as hybrid heterogeneous/homogeneous catalysts. Using styrene (derivative) building blocks,...

Abstract Well‐defined amphiphilic PCL‐ b ‐PDMAEMA block copolymers were successfully synthesized by a combination of ATRP and “click” chemistry following either commutative two‐step procedure or straightforward one‐pot process using CuBr · 3Bpy as the sole catalyst. Compared to traditional coupling method, combining click even in “one‐pot” allows preparation diblock characterized narrow molecular weight distribution quantitative conversion azides alkynes into triazole functions. Moreover,...

Self-destruction: Attachment of a photoreactive RuII complex to guanine-containing oligonucleotide has led an innovative biomolecular tool for gene silencing studies. This conjugate can be selectively photo-cross-linked with its complementary strand but undergoes self-inhibition (or "seppuku") process in the presence noncomplementary target (see picture), which is attractive strategy avoid undesired secondary photoeffects. The design specific DNA or RNA damaging agents may achieved by...

Cobalt-mediated radical coupling (CMRC) is successfully applied to poly(vinyl acetate) (PVAc) and poly(N-vinylpyrrolidone) (PNVP) precursors for the first time. The process based on addition of isoprene onto polymer chains preformed by controlled polymerization with cobalt complexes (CMRP). extents were high (>90%) moderate (75−80%) PVAc PNVP precursors, respectively. Effects length conditions used in step efficiency are discussed. Mass spectrometry (MS) nuclear magnetic resonance (NMR)...