Substitution reactions of 6I-O-p-tolylsulfonylcyclomaltoheptaose with alkyl- and arylamines in 1-... more Substitution reactions of 6I-O-p-tolylsulfonylcyclomaltoheptaose with alkyl- and arylamines in 1-methyl-2-pyrrolidinone and various pyrrolidinones were investigated. An unexpected reaction of the tosyl group with pyrrolidinones was observed resulting in products deriving from nucleophilic attack by the lactam carbonyl oxygen and further opening of the heterocyclic ring. The new compounds have been fully characterized by ESIMS and NMR analyses.
Pt nanoclusters have been generated by reaction of Pt vapour and mesitylene vapour and the role o... more Pt nanoclusters have been generated by reaction of Pt vapour and mesitylene vapour and the role of the mesitylene/platinum ratio and the Pt particle size has been evaluated, quenching the resulting mesitylene solvated Pt atoms with 1,3-divinyltetramethyldisiloxane (DVS) as additional ligand. The Pt particle sizes have been estimated on the basis of DOSY (Diffusion-Ordered SpectroscopY) analysis and information on their structure features have been obtained by combined use of 2D NMR techniques.
Hybrid halide perovskites have emerged as promising active constituents of next generation soluti... more Hybrid halide perovskites have emerged as promising active constituents of next generation solution processable optoelectronic devices. During their assembling process, perovskite components undergo very complex dynamic equilibria starting in solution and progressing throughout film formation. Finding a methodology to control and affect these equilibria, responsible for the unique morphological diversity observed in perovskite films, constitutes a fundamental step towards a reproducible material processability. Here we propose the exploitation of polymer matrices as cooperative assembling components of novel perovskite CH3NH3PbI3 : polymer composites, in which the control of the chemical interactions in solution allows a predictable tuning of the final film morphology. We reveal that the nature of the interactions between perovskite precursors and polymer functional groups, probed by Nuclear Magnetic Resonance (NMR) spectroscopy and Dynamic Light Scattering (DLS) techniques, allows the control of aggregates in solution whose characteristics are strictly maintained in the solid film, and permits the formation of nanostructures that are inaccessible to conventional perovskite depositions. These results demonstrate how the fundamental chemistry of perovskite precursors in solution has a paramount influence on controlling and monitoring the final morphology of CH3NH3PbI3 (MAPbI3) thin films, foreseeing the possibility of designing perovskite : polymer composites targeting diverse optoelectronic applications.
The use of permethylated beta-cyclodextrin as chiral solvating agent for NMR spectroscopy allowed... more The use of permethylated beta-cyclodextrin as chiral solvating agent for NMR spectroscopy allowed us to determine the enantiomeric purity of chiral aromatic hydrocarbons as well as the enantiomeric purity and absolute configuration of chiral trisubstituted allenes devoid of polar functional groups. The enantiomeric excesses of the trisubstituted allenes have been also determined by 195Pt NMR spectroscopy of the diastereoisomeric trans-dichloro[(S)-alpha-phenylethyl-amine](allene)Pt(II) complexes.
High resolution NMR spectroscopy gave very useful tools to compare hyaluronic acids (HAs) from di... more High resolution NMR spectroscopy gave very useful tools to compare hyaluronic acids (HAs) from different preparative routes, pointing out differences of molecular weights or the presence of residual low molecular weight components. INTRODUCTION Polysaccharides are relatively complex carbohydrates. They provide good mechanical properties for applications as fibers, films, adhesives, rheology modifiers, hydrogels, emulsifiers and drug delivery agents. Among polysaccharides, hyaluronic acid (HA) is known to be a polyanion alternating 2-acetamide-2-deoxy-β-D-glucopyranose and β-D-glucopyranuronic acid residues. It occurs in many living systems and its pharmacological relevance has been widely demonstrated. In view of the increasing interest in the industrial production of hyaluronate polymers, several theoretical and experimental investigations have been devoted to their solution properties, even if rheological data are conflicting in some cases as the consequence of HAs polyelectrolyte...
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The stereochemical features of 2,8,14,20-tetrakis(d-leucyl-d-valinamido)resorc[4]arenecarboxylic ... more The stereochemical features of 2,8,14,20-tetrakis(d-leucyl-d-valinamido)resorc[4]arenecarboxylic acid and the N-succinyl-l-alanyl-l-alanyl-l-prolyl-l-phenylalanine-4-nitroanilide polypeptide substrate were investigated by nuclear magnetic resonance spectroscopy. Proton selective relaxation parameters gave the basis for the inhibitory activity of resorcin[4]arene in the hydrolysis of the polypeptide substrate by α-chymotrypsin. Results showed that an interaction between the resorcin[4]arene and α-chymotrypsin does occur, and involves the hydrophobic moiety of the macrocycle. This interaction is further reinforced by polar groups located on the side chains of the resorcin[4]arene, whereas the macrocycle-polypeptide substrate interaction is negligible. Conformational analysis and interaction studies carried out by molecular modeling are in good agreement with the NMR data, thus providing an additional support to the rationalization of the inhibitory potential of resorcin[4]arenes on th...
This chapter will describe the general features and main categories of chiral solvating agents (C... more This chapter will describe the general features and main categories of chiral solvating agents (CSAs) for NMR spectroscopy, spanning from low-medium sized CSAs to macrocyclic ones. CSAs based on chiral ionic liquids (CILs) will be introduced in view of their increasing popularity, and, finally, a short paragraph will be dedicated to special applications of CSAs in particular experimental conditions. Several valuable works, which are mainly devoted to investigate enantiodifferentiation mechanisms by NMR, will not be discussed. The main objective is to identify the current trend in the research areas dedicated to the development of new CSAs for NMR spectroscopy.
Substitution reactions of 6I-O-p-tolylsulfonylcyclomaltoheptaose with alkyl- and arylamines in 1-... more Substitution reactions of 6I-O-p-tolylsulfonylcyclomaltoheptaose with alkyl- and arylamines in 1-methyl-2-pyrrolidinone and various pyrrolidinones were investigated. An unexpected reaction of the tosyl group with pyrrolidinones was observed resulting in products deriving from nucleophilic attack by the lactam carbonyl oxygen and further opening of the heterocyclic ring. The new compounds have been fully characterized by ESIMS and NMR analyses.
Pt nanoclusters have been generated by reaction of Pt vapour and mesitylene vapour and the role o... more Pt nanoclusters have been generated by reaction of Pt vapour and mesitylene vapour and the role of the mesitylene/platinum ratio and the Pt particle size has been evaluated, quenching the resulting mesitylene solvated Pt atoms with 1,3-divinyltetramethyldisiloxane (DVS) as additional ligand. The Pt particle sizes have been estimated on the basis of DOSY (Diffusion-Ordered SpectroscopY) analysis and information on their structure features have been obtained by combined use of 2D NMR techniques.
Hybrid halide perovskites have emerged as promising active constituents of next generation soluti... more Hybrid halide perovskites have emerged as promising active constituents of next generation solution processable optoelectronic devices. During their assembling process, perovskite components undergo very complex dynamic equilibria starting in solution and progressing throughout film formation. Finding a methodology to control and affect these equilibria, responsible for the unique morphological diversity observed in perovskite films, constitutes a fundamental step towards a reproducible material processability. Here we propose the exploitation of polymer matrices as cooperative assembling components of novel perovskite CH3NH3PbI3 : polymer composites, in which the control of the chemical interactions in solution allows a predictable tuning of the final film morphology. We reveal that the nature of the interactions between perovskite precursors and polymer functional groups, probed by Nuclear Magnetic Resonance (NMR) spectroscopy and Dynamic Light Scattering (DLS) techniques, allows the control of aggregates in solution whose characteristics are strictly maintained in the solid film, and permits the formation of nanostructures that are inaccessible to conventional perovskite depositions. These results demonstrate how the fundamental chemistry of perovskite precursors in solution has a paramount influence on controlling and monitoring the final morphology of CH3NH3PbI3 (MAPbI3) thin films, foreseeing the possibility of designing perovskite : polymer composites targeting diverse optoelectronic applications.
The use of permethylated beta-cyclodextrin as chiral solvating agent for NMR spectroscopy allowed... more The use of permethylated beta-cyclodextrin as chiral solvating agent for NMR spectroscopy allowed us to determine the enantiomeric purity of chiral aromatic hydrocarbons as well as the enantiomeric purity and absolute configuration of chiral trisubstituted allenes devoid of polar functional groups. The enantiomeric excesses of the trisubstituted allenes have been also determined by 195Pt NMR spectroscopy of the diastereoisomeric trans-dichloro[(S)-alpha-phenylethyl-amine](allene)Pt(II) complexes.
High resolution NMR spectroscopy gave very useful tools to compare hyaluronic acids (HAs) from di... more High resolution NMR spectroscopy gave very useful tools to compare hyaluronic acids (HAs) from different preparative routes, pointing out differences of molecular weights or the presence of residual low molecular weight components. INTRODUCTION Polysaccharides are relatively complex carbohydrates. They provide good mechanical properties for applications as fibers, films, adhesives, rheology modifiers, hydrogels, emulsifiers and drug delivery agents. Among polysaccharides, hyaluronic acid (HA) is known to be a polyanion alternating 2-acetamide-2-deoxy-β-D-glucopyranose and β-D-glucopyranuronic acid residues. It occurs in many living systems and its pharmacological relevance has been widely demonstrated. In view of the increasing interest in the industrial production of hyaluronate polymers, several theoretical and experimental investigations have been devoted to their solution properties, even if rheological data are conflicting in some cases as the consequence of HAs polyelectrolyte...
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The stereochemical features of 2,8,14,20-tetrakis(d-leucyl-d-valinamido)resorc[4]arenecarboxylic ... more The stereochemical features of 2,8,14,20-tetrakis(d-leucyl-d-valinamido)resorc[4]arenecarboxylic acid and the N-succinyl-l-alanyl-l-alanyl-l-prolyl-l-phenylalanine-4-nitroanilide polypeptide substrate were investigated by nuclear magnetic resonance spectroscopy. Proton selective relaxation parameters gave the basis for the inhibitory activity of resorcin[4]arene in the hydrolysis of the polypeptide substrate by α-chymotrypsin. Results showed that an interaction between the resorcin[4]arene and α-chymotrypsin does occur, and involves the hydrophobic moiety of the macrocycle. This interaction is further reinforced by polar groups located on the side chains of the resorcin[4]arene, whereas the macrocycle-polypeptide substrate interaction is negligible. Conformational analysis and interaction studies carried out by molecular modeling are in good agreement with the NMR data, thus providing an additional support to the rationalization of the inhibitory potential of resorcin[4]arenes on th...
This chapter will describe the general features and main categories of chiral solvating agents (C... more This chapter will describe the general features and main categories of chiral solvating agents (CSAs) for NMR spectroscopy, spanning from low-medium sized CSAs to macrocyclic ones. CSAs based on chiral ionic liquids (CILs) will be introduced in view of their increasing popularity, and, finally, a short paragraph will be dedicated to special applications of CSAs in particular experimental conditions. Several valuable works, which are mainly devoted to investigate enantiodifferentiation mechanisms by NMR, will not be discussed. The main objective is to identify the current trend in the research areas dedicated to the development of new CSAs for NMR spectroscopy.
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