A5091511715- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Supramolecular Chemistry and Complexes
- Crystallography and molecular interactions
- Molecular Sensors and Ion Detection
- Chemical Synthesis and Analysis
- Carbohydrate Chemistry and Synthesis
- Recycling and Waste Management Techniques
- Luminescence and Fluorescent Materials
- Microplastics and Plastic Pollution
- Metal-Organic Frameworks: Synthesis and Applications
- Nanofabrication and Lithography Techniques
- Supramolecular Self-Assembly in Materials
- Molecular spectroscopy and chirality
- Innovative Microfluidic and Catalytic Techniques Innovation
- biodegradable polymer synthesis and properties
- Mass Spectrometry Techniques and Applications
- Biochemical and Structural Characterization
- Advanced Polymer Synthesis and Characterization
- Synthesis and Catalytic Reactions
- Multicomponent Synthesis of Heterocycles
- Advanced NMR Techniques and Applications
- Synthesis of Organic Compounds
- Phytochemical compounds biological activities
- Covalent Organic Framework Applications
University of Salerno
2016-2024
The presence in seawater of low-molecular-weight polyethylene (PE) and polydimethylsiloxane (PDMS), synthetic polymers with high chemical resistance, has been demonstrated this study for the first time by developing a novel methodology their recovery quantification from surface seawater. These polymer debris (SPD) very low molecular weights sizes nano- micro-metre range have escaped conventional analytical methods. SPD easily recovered water samples (2 L) through filtration nitrocellulose...
Optical chirality sensing has gained significant attention in recent years. Within this field, the quest for stereodynamic chiroptical probes capable of detecting cryptochiral guests presents a formidable challenge. Macrocycles exhibiting planar have emerged as promising candidates amplifying guests. In study, we demonstrate that formation host-guest complexes between molecules and chiral prismarenes triggers electronic circular dichroism (ECD) signals via complexation-induced amplification....
The confinement of substrates inside the cavity self-assembled capsules makes it possible to effectively catalyze organic reactions in a way that is analogous how enzymes work biological systems. Due steric constraints, solvent exclusion, intermediates stabilization, and conformational control substrates, chemical taking place confined space may exhibit unique processes. As result, fundamental rules reactivity are frequently broken. hexameric capsule CR, an intriguing supramolecular assembly...
The confused-prism[5]arene macrocycle (c-PrS[5]Me ) shows conformational adaptive behavior in the presence of ammonium guests. Upon guest inclusion, 1,4-bridged naphthalene flap reverses its planar chirality from pS to pR (with reference pS(pR)4 enantiomer). Stereoselective directional threading is also observed axles, which up/down stereoisomers homochiral (pR)5 -c-PrS[5]Me pseudorotaxanes are formed.
Peptoids are oligomers of N-substituted glycines with predictable folding and strong potentials as guest-binding receptor molecules. In this contribution, we investigate the structural features a series designed symmetric cyclic octamer peptoids (with methoxyethyl/propargyl side chains) free hosts reveal their morphologic changes in presence sodium alkylammonium guests tetrakis[3,5-bis(trifluoromethyl)phenyl]borate salts, reporting first case reversible adaptive switching between defined...
Formation of stable porous frameworks based on cyclic peptoids can be triggered by strategic choice appropriate side chains. In this contribution we demonstrate that substitution distal propargyl chains with methoxyethyl groups in a fully propargylated octamer peptoid (cyclo-(Npa)8 1) greatly improves the solid state stability inducing permanent one-dimensional porosity compound (cyclo-[(NPa)3(Nme)]2 2, Npa = N-(propargyl)glycine, Nme N-(methoxyethyl)glycine). both compounds macrocycles...
The investigation of the solid state assembly propargyl substituted hexa- and octacyclic peptoids highlights effect ring size in determining packing arrangement macrocycles. A layered is obtained case hexacyclic peptoid 1 a tubular 2. Guest molecules either intercalate between layers as or are located within nanotube
The hexameric resorcinarene capsule is able to promote carbocation catalysis inside its cavity.
Cone-shaped calix[4]arene-tetrol 3 has the ability to form open structures due presence of four OH groups at upper rim, which allows construction H-bonded supramolecular organic frameworks (SOFs). In water, SOF-1 is formed, contains hydrophilic channels (mean diameter 8.5 Å) contoured by p-phenolic groups. acetonitrile, SOF-2 smaller hydrophobic 6.6 delimited aromatic walls. The Na+@3 complex, hosts acetonitrile molecules in calixarene cavities, and dibromo-calix[4]arene-diol 5 give rise...
Friedel-Crafts benzoylation of N-methylpyrrole 2 can run inside the confined space hexameric resorcinarene capsule C. The bridged water molecules at corner C act as H-bonding donor groups to polarize C-Cl bond benzoyl chlorides 3a-f. Confinement effects on regiochemistry FC are observed. nature para-substituents 3a-f and their ability establish H-bonds with work synergistically steric constrictions imposed by drive products 4a-f. QM investigations indicate that cavity C, has a bimolecular...
In this paper, we report the synthesis, structural characterization, and solvatochromic properties of a N-linked p-pyridiniumcalix[4]arenediol derivative 1. solid state, 1 forms dimeric assembly stabilized by network weak H-bonding interactions involving acetonitrile solvent molecules. solution, shows peculiar negative solvatochromism which was rationalized with aid TD-DFT calculations. The species responsible for phenomenon is monodeprotonated betainic form easily formed at pH close to neutrality.
Calix[6]arenes disubstituted at the methylene bridges, which are stable in cone or 1,2,3-alternate conformation, form pseudorotaxanes with dialkylammonium axles. The wheel-based 10-100 times more than those obtained native conformationally mobile calix[6]arene wheel, as a consequence of their higher degree preorganization. threading calix[6]arenes is unprecedented literature. Therefore, very peculiar NMR features here evidenced for this process involving less symmetrical implies...
The synthesis of calix[4]- and -[6]arene derivatives P6(H)22+·(Cl–)2, V4(H)24+·(Cl–)2·(I–)2, V6(H)24+·(Cl–)2·(I–)2 bearing N-linked pyridinium (P) viologen (V) units at the upper rim is described here. A rare example an anionic conformational template reported for p-pyridiniumcalix[6]arene P6(H)22+, which adopts a 1,3,5-alternate conformation in presence chloride anions. Derivatives V6(H)24+·(Cl–)2·(I–)2, V4(H)24+·(Cl–)2·(I–)2 show negative solvatochromism, while their UV–vis acid–base...
Calix[6]arenes bearing adamantyl groups at the exo-rim form pseudorotaxanes with dialkylammonium axles paired to weakly coordinating [B(ArF)4]− anion. The exo-adamantyl give rise a more efficient threading respect exo-tert-butyl ones, leading apparent association constants than one order of magnitude higher. This improved stability has been ascribed favorable van der Waals interactions exo-adamantyls versus exo-tert-butyls cationic axle. endo-OH functions less endo-OR in line what was known...
Chiral mono- and bis-(thio)urea supramolecular organocatalysts were studied in the enantioselective vinylogous addition reaction of 2-trimethylsilyloxyfuran (TMSOF) to carbonylic compounds; corresponding chiral γ-hydroxymethyl-butenolides are obtained good yields with high enantiomeric excesses. The catalyst structure, as well conditions, strongly influence efficiency reaction. conformational features mono(thio)urea catalysts 2 3 bis(thio)urea 7 8 investigated by DFT calculations along...
We obtained Multi-QACs (quaternary ammonium compounds) by introducing tetraalkylammonium groups on the wider rim of resorcin[4]arenes. These new compounds exhibit significant bacteriostatic activity and a surprising multivalent effect.
We recently introduced calix[
The synthesis of the triple-calix[6]arene derivative 6 in which three calix[6]arene macrocycles are linked to a central 1,3,5-trimethylbenzene moiety is reported. Derivative able give multiple-threading processes presence dialkylammonium axles. formation pseudo[2]rotaxane, pseudo[3]rotaxane, and pseudo[4]rotaxane by threading one, two, three, respectively, calix-wheels has been studied 1D 2D NMR, DOSY, ESI-FT-ICR MS/MS experiments. use directional alkylbenzylammonium axle led stereoselective...
Hexahexyloxycalix[6]arene 2b leads to the endo-cavity complexation of linear and branched alkylammonium guests showing a conformational adaptive behavior in CDCl3 solution. Linear n-pentylammonium guest 6a+ induces cone conformation at expense 1,2,3-alternate, which is most abundant conformer absence guest. In different way, guests, such as tert-butylammonium 6b+ isopropylammonium 6c+, select 1,2,3-alternate favored (6b+/6c+⊂2b1,2,3-alt), but other complexes adopts conformations, namely,...
Hexamethoxycalix[6]arene 3 forms a directional pseudorotaxane complex with the chiral axle (S)-(α-methyl-benzyl)benzylammonium 2+. Between two (endo-chiral)-2+@3 and (exo-chiral)-2+@3 stereoisomers, former is preferentially formed. This result confirms validity of “endo-α-methyl-benzyl rule”, previously reported by us. DFT calculations suggest that C-H … π interactions between methyl group 2+ calixarene aromatic rings, determine stereoselectivity threading process toward preference”. An...