Tiziana Benincori - Academia.edu (original) (raw)
Papers by Tiziana Benincori
ChemElectroChem, 2021
A series of 2,2’‐biindole‐based inherently chiral electroactive monomers are comparatively invest... more A series of 2,2’‐biindole‐based inherently chiral electroactive monomers are comparatively investigated with their 3,3’ analogues as an excellent study case of two equivalent redox centres interacting through a torsional barrier. The twin peak potential splitting observed in voltammetry for the first oxidation of the biheteroaromatic core accounts for the energy barrier height: the lower the barrier, the larger the peak potential splitting, with modulation by solvent and temperature. The height of the energy barrier is determining for the electrochemical and spectroscopic features of the monomers as well as for their configurational stability and applicability for enantioselection purposes. The 3,3’ monomers, featuring large twin peak splittings in CV, are “trópos” systems with a low torsional barrier, so they cannot exist as stable enantiomers at room temperature. Instead their 2,2’ isomers, with much smaller twin peak splittings, are “átropos” systems and can be separated by enant...
Analytical and Bioanalytical Chemistry, 2016
BInherently chiral^thiophene-based electroactive oligomer films have recently been shown to exhib... more BInherently chiral^thiophene-based electroactive oligomer films have recently been shown to exhibit outstanding chirality manifestations. One of the most exciting among them is an unprecedented enantioselection ability as electrode surfaces. In fact, in preliminary chiral voltammetry experiments, the new electrodes have been shown to both discriminate the enantiomers of chiral probes (either enantiopure or in a mixture, in terms of large differences in peak potentials) and quantify them (in terms of linear dynamic ranges in peak currents), without the need for preliminary separation steps. Such ability has now been tested on a series of chiral DOPArelated molecules, from phenolic amino acid tyrosine (together with its methyl ester) to catecholic amino acid DOPA (together with its methyl ester), to catecholamine epinephrine (adrenaline). The wide-range enantioselectivity of the new inherently chiral electrode surfaces is fully confirmed, as large peak potential differences are obtained for probe enantiomers of the whole series working in common aqueous buffers. M o r e o v e r, i n t e r e s t i n g m o d u l a t i n g e f f e c t s o n enantiodiscrimination can be observed as a function of both molecular structure and pH.
Biosensors & bioelectronics, Jan 14, 2015
With an established procedure of molecular imprinting, a synthetic polymer receptor for the neopt... more With an established procedure of molecular imprinting, a synthetic polymer receptor for the neopterin cancer biomarker was devised and used as a recognition unit of a potentiometric chemosensor. For that, bis-bithiophene derivatized with cytosine and bithiophene derivatized with boronic acid were used as functional monomers. The open-circuit potential (OCP) based transduction under flow-injection analysis conditions (FIA) determined neopterin in the concentration range of 0.15-2.5mM with the 22µM limit of detection (LOD) and 7.01(±0.15)mVmM(-1) sensitivity indicating its potential suitability in clinical analysis applications. The molecularly imprinted polymer (MIP) film showed an appreciable apparent imprinting factor of ~6. The chemosensor successfully discriminated the interferences including the 6-biopterin and pterin structural analogs of neopterin as well as glucose and creatinine. Moreover, it determined neopterin in synthetic serum samples.
International Conference on Science and Technology of Synthetic Metals, 1994
Complexes between transition metals ions and macromolecular ligands have been widely studied in t... more Complexes between transition metals ions and macromolecular ligands have been widely studied in the past, due to their interesting electrochemical and catalytic properties. Polymers with a x-conjugated backbone, on the other hand, have some peculiar electrical properties that make them interesting materials for molecular electronics.
ChemInform, 2010
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.
Tetrahedron: Asymmetry, 2004
... BITIOP)Ru(CF 3 COO) 2 in comparison with (BINAP)Ru(CH 3 COO) 2 under analogous experimental c... more ... BITIOP)Ru(CF 3 COO) 2 in comparison with (BINAP)Ru(CH 3 COO) 2 under analogous experimental conditions, was appreciable, even though too modest to be considered satisfactory: about 10 h were saved over a nearly five day reaction time required to drive the reaction ...
The Journal of Organic Chemistry, 1988
Synthese par cyclisation d'esters d'aryle des acides pyruvohydrazoniques et thiopyruvohyd... more Synthese par cyclisation d'esters d'aryle des acides pyruvohydrazoniques et thiopyruvohydrazoniques et de arylamides d'acides pyruvohydrazoniques avec l'acide polyphosphorique
Chromatographia, 2002
Summary Resolution of the enantiomers of new racemic diphosphines, which are very useful ligands... more Summary Resolution of the enantiomers of new racemic diphosphines, which are very useful ligands for stereoselective catalysts, and of the corresponding phosphine oxides has been investigated by high-performance liquid chromatography (HPLC) on four different chiral stationary phases (CSP)—Chiralpak AD, Whelk-01, and Supelcosil naphthylurea and phenylurea columns. The mobile phases were optimized to achieve separation of the enantiomers. α andR S values
Chemistry of Materials, 2020
Transduction of chiral information can be achieved at different length scales. Among all possible... more Transduction of chiral information can be achieved at different length scales. Among all possible approaches, we propose in this work a straightforward concept to transfer chiral features from the molecular level to the shape of macroscopic objects by combining the concepts of inherently chiral oligomers and bipolar electrochemistry. Hybrid freestanding lamellar films, composed of polypyrrole and the two oligomeric antipodes of a chiral monomer, are exposed in solution to a chiral target molecule (i.e. Land D-DOPA) in the presence of an electric field. This leads to an electrochemically induced deformation of the film, which in fine results in one or the other of two macroscopic enantiomorphs, depending on which stereoisomer is present in the solution.
Chemistry – A European Journal, 2021
Abstract A family of inherently chiral electroactive selectors based on the 2,2’‐biindole atropis... more Abstract A family of inherently chiral electroactive selectors based on the 2,2’‐biindole atropisomeric scaffold, of easy synthesis and modulable functional properties, is studied in cascade in two enantioselection contexts. They are at first investigated as probes in enantioselective HPLC, studying molecular structure and temperature effects, and achieving very efficient semipreparative enantioseparation. The enantiomers thus obtained, of remarkable chiroptical features (optical rotation as well as circular dichroism), are successfully applied as selectors in chiral voltammetry in different media for discrimination of the enantiomers of chiral electroactive probes, either by conversion into enantiopure electroactive electrode surfaces by electrooligomerization on glassy carbon substrate (the two monomers with shorter alkyl chains), or as chiral additive in achiral ionic liquid (the monomer with longest alkyl chains). Discrimination is conveniently and reproducibly achieved in terms of significant potential differences for the two enantiomers, specularly inverting either probe or selector configuration. In one case successful discrimination is also observed with the two probe enantiomers concurrently present, either as racemate or with enantiomeric excesses, neatly accounted for by the peak current ratios.
Chemical Science, 2019
The new inherently chiral material shows outstanding chirality manifestations with chiral probes,... more The new inherently chiral material shows outstanding chirality manifestations with chiral probes, as well as with circularly polarized light components and electron spins.
ACS Measurement Science Au
Straightforward enantioselective analytical methods are very important for drug safety, consideri... more Straightforward enantioselective analytical methods are very important for drug safety, considering that in certain cases one of the two enantiomers of a chiral molecule might be harmful for humans. In this work, we propose a simple system for the direct and easy read-out of the enantiomeric excess of 3,4-dihydroxyphenylalanine (DOPA) as a model analyte. A conducting oligomer, i.e. oligo-(3,3′-dibenzothiophene), bearing inherently chiral features, is electrogenerated on a polypyrrole film. The resulting freestanding hybrid material is used as a wireless enantioselective actuator in a bipolar electrochemical cell. Combining in a single setup two individual actuators with opposite chiral features allows a direct visual read-out of enantiomeric excess, as the bending amplitude of each of the two actuators is directly correlated with the concentration of the corresponding stereoisomer of the analyte. Optimization of the experimental parameters results in efficient bending, giving access to the percentage values of the enantiomeric excess in mixtures containing different ratios of the antipodes, thus opening the way to potential applications for chiral in situ analysis.
![Research paper thumbnail of Configurationally stable molecular propellers: the [corrected] resolution of phosphorus-centered [corrected] residual enantiomers](https://attachments.academia-assets.com/75731521/thumbnails/1.jpg)
](General procedure for the preparation of phosphine oxides 1a-c: A mixture of phosphorus oxybromid... more General procedure for the preparation of phosphine oxides 1a-c: A mixture of phosphorus oxybromide (1 mmol) and pyridine (9 mmoles) was added to the suitable N-methyl-2-alkylindole (3.8 mmoles) under nitrogen. The reaction mixture was heated at 90°C under stirring for 18 h, then diluted with dichloromethane and the resulting solution exhaustively extracted with a 1N HCl solution. The organic layer was washed with H 2 O, dried over Na 2 SO 4 and evaporated to dryness to give a residue which was chromatographed on a silica gel column to separate the phosphine oxide 1 from unreacted N-methyl-2-alkylindole, which was eluted first.
Nature Chemistry
A key approach for designing bioinspired machines is to transfer concepts from nature to man-made... more A key approach for designing bioinspired machines is to transfer concepts from nature to man-made structures by integrating biomolecules into artificial mechanical systems. This strategy allows the conversion of molecular information into macroscopic action. Here, we describe the design and dynamic behaviour of hybrid bioelectrochemical swimmers that move spontaneously at the air–water interface. Their motion is governed by the diastereomeric interactions between immobilized enantiopure oligomers and the enantiomers of a chiral probe molecule present in solution. These dynamic bipolar systems are able to convert chiral information present at the molecular level into enantiospecific macroscopic trajectories. Depending on the enantiomer in solution, the swimmers will move clockwise or anticlockwise; the concept can also be used for the direct visualization of the degree of enantiomeric excess by analysing the curvature of the trajectories. Deciphering in such a straightforward way the enantiomeric ratio could be useful for biomedical applications, for the read-out of food quality or as a more general analogue of polarimetric measurements. Self-propelled artificial chemical swimmers have previously been developed for chemical sensing. Now, hybrid bioelectrochemical swimmers, capable of translating chiral molecular information into macroscopic motion, have been developed. Diastereomeric interactions between enantiopure oligomers immobilized on the swimmer and a chiral molecule present in solution control the trajectory of the device.
European Journal of Organic Chemistry
ChemElectroChem, 2021
A series of 2,2’‐biindole‐based inherently chiral electroactive monomers are comparatively invest... more A series of 2,2’‐biindole‐based inherently chiral electroactive monomers are comparatively investigated with their 3,3’ analogues as an excellent study case of two equivalent redox centres interacting through a torsional barrier. The twin peak potential splitting observed in voltammetry for the first oxidation of the biheteroaromatic core accounts for the energy barrier height: the lower the barrier, the larger the peak potential splitting, with modulation by solvent and temperature. The height of the energy barrier is determining for the electrochemical and spectroscopic features of the monomers as well as for their configurational stability and applicability for enantioselection purposes. The 3,3’ monomers, featuring large twin peak splittings in CV, are “trópos” systems with a low torsional barrier, so they cannot exist as stable enantiomers at room temperature. Instead their 2,2’ isomers, with much smaller twin peak splittings, are “átropos” systems and can be separated by enant...
Analytical and Bioanalytical Chemistry, 2016
BInherently chiral^thiophene-based electroactive oligomer films have recently been shown to exhib... more BInherently chiral^thiophene-based electroactive oligomer films have recently been shown to exhibit outstanding chirality manifestations. One of the most exciting among them is an unprecedented enantioselection ability as electrode surfaces. In fact, in preliminary chiral voltammetry experiments, the new electrodes have been shown to both discriminate the enantiomers of chiral probes (either enantiopure or in a mixture, in terms of large differences in peak potentials) and quantify them (in terms of linear dynamic ranges in peak currents), without the need for preliminary separation steps. Such ability has now been tested on a series of chiral DOPArelated molecules, from phenolic amino acid tyrosine (together with its methyl ester) to catecholic amino acid DOPA (together with its methyl ester), to catecholamine epinephrine (adrenaline). The wide-range enantioselectivity of the new inherently chiral electrode surfaces is fully confirmed, as large peak potential differences are obtained for probe enantiomers of the whole series working in common aqueous buffers. M o r e o v e r, i n t e r e s t i n g m o d u l a t i n g e f f e c t s o n enantiodiscrimination can be observed as a function of both molecular structure and pH.
Biosensors & bioelectronics, Jan 14, 2015
With an established procedure of molecular imprinting, a synthetic polymer receptor for the neopt... more With an established procedure of molecular imprinting, a synthetic polymer receptor for the neopterin cancer biomarker was devised and used as a recognition unit of a potentiometric chemosensor. For that, bis-bithiophene derivatized with cytosine and bithiophene derivatized with boronic acid were used as functional monomers. The open-circuit potential (OCP) based transduction under flow-injection analysis conditions (FIA) determined neopterin in the concentration range of 0.15-2.5mM with the 22µM limit of detection (LOD) and 7.01(±0.15)mVmM(-1) sensitivity indicating its potential suitability in clinical analysis applications. The molecularly imprinted polymer (MIP) film showed an appreciable apparent imprinting factor of ~6. The chemosensor successfully discriminated the interferences including the 6-biopterin and pterin structural analogs of neopterin as well as glucose and creatinine. Moreover, it determined neopterin in synthetic serum samples.
International Conference on Science and Technology of Synthetic Metals, 1994
Complexes between transition metals ions and macromolecular ligands have been widely studied in t... more Complexes between transition metals ions and macromolecular ligands have been widely studied in the past, due to their interesting electrochemical and catalytic properties. Polymers with a x-conjugated backbone, on the other hand, have some peculiar electrical properties that make them interesting materials for molecular electronics.
ChemInform, 2010
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.
Tetrahedron: Asymmetry, 2004
... BITIOP)Ru(CF 3 COO) 2 in comparison with (BINAP)Ru(CH 3 COO) 2 under analogous experimental c... more ... BITIOP)Ru(CF 3 COO) 2 in comparison with (BINAP)Ru(CH 3 COO) 2 under analogous experimental conditions, was appreciable, even though too modest to be considered satisfactory: about 10 h were saved over a nearly five day reaction time required to drive the reaction ...
The Journal of Organic Chemistry, 1988
Synthese par cyclisation d'esters d'aryle des acides pyruvohydrazoniques et thiopyruvohyd... more Synthese par cyclisation d'esters d'aryle des acides pyruvohydrazoniques et thiopyruvohydrazoniques et de arylamides d'acides pyruvohydrazoniques avec l'acide polyphosphorique
Chromatographia, 2002
Summary Resolution of the enantiomers of new racemic diphosphines, which are very useful ligands... more Summary Resolution of the enantiomers of new racemic diphosphines, which are very useful ligands for stereoselective catalysts, and of the corresponding phosphine oxides has been investigated by high-performance liquid chromatography (HPLC) on four different chiral stationary phases (CSP)—Chiralpak AD, Whelk-01, and Supelcosil naphthylurea and phenylurea columns. The mobile phases were optimized to achieve separation of the enantiomers. α andR S values
Chemistry of Materials, 2020
Transduction of chiral information can be achieved at different length scales. Among all possible... more Transduction of chiral information can be achieved at different length scales. Among all possible approaches, we propose in this work a straightforward concept to transfer chiral features from the molecular level to the shape of macroscopic objects by combining the concepts of inherently chiral oligomers and bipolar electrochemistry. Hybrid freestanding lamellar films, composed of polypyrrole and the two oligomeric antipodes of a chiral monomer, are exposed in solution to a chiral target molecule (i.e. Land D-DOPA) in the presence of an electric field. This leads to an electrochemically induced deformation of the film, which in fine results in one or the other of two macroscopic enantiomorphs, depending on which stereoisomer is present in the solution.
Chemistry – A European Journal, 2021
Abstract A family of inherently chiral electroactive selectors based on the 2,2’‐biindole atropis... more Abstract A family of inherently chiral electroactive selectors based on the 2,2’‐biindole atropisomeric scaffold, of easy synthesis and modulable functional properties, is studied in cascade in two enantioselection contexts. They are at first investigated as probes in enantioselective HPLC, studying molecular structure and temperature effects, and achieving very efficient semipreparative enantioseparation. The enantiomers thus obtained, of remarkable chiroptical features (optical rotation as well as circular dichroism), are successfully applied as selectors in chiral voltammetry in different media for discrimination of the enantiomers of chiral electroactive probes, either by conversion into enantiopure electroactive electrode surfaces by electrooligomerization on glassy carbon substrate (the two monomers with shorter alkyl chains), or as chiral additive in achiral ionic liquid (the monomer with longest alkyl chains). Discrimination is conveniently and reproducibly achieved in terms of significant potential differences for the two enantiomers, specularly inverting either probe or selector configuration. In one case successful discrimination is also observed with the two probe enantiomers concurrently present, either as racemate or with enantiomeric excesses, neatly accounted for by the peak current ratios.
Chemical Science, 2019
The new inherently chiral material shows outstanding chirality manifestations with chiral probes,... more The new inherently chiral material shows outstanding chirality manifestations with chiral probes, as well as with circularly polarized light components and electron spins.
ACS Measurement Science Au
Straightforward enantioselective analytical methods are very important for drug safety, consideri... more Straightforward enantioselective analytical methods are very important for drug safety, considering that in certain cases one of the two enantiomers of a chiral molecule might be harmful for humans. In this work, we propose a simple system for the direct and easy read-out of the enantiomeric excess of 3,4-dihydroxyphenylalanine (DOPA) as a model analyte. A conducting oligomer, i.e. oligo-(3,3′-dibenzothiophene), bearing inherently chiral features, is electrogenerated on a polypyrrole film. The resulting freestanding hybrid material is used as a wireless enantioselective actuator in a bipolar electrochemical cell. Combining in a single setup two individual actuators with opposite chiral features allows a direct visual read-out of enantiomeric excess, as the bending amplitude of each of the two actuators is directly correlated with the concentration of the corresponding stereoisomer of the analyte. Optimization of the experimental parameters results in efficient bending, giving access to the percentage values of the enantiomeric excess in mixtures containing different ratios of the antipodes, thus opening the way to potential applications for chiral in situ analysis.
General procedure for the preparation of phosphine oxides 1a-c: A mixture of phosphorus oxybromid... more General procedure for the preparation of phosphine oxides 1a-c: A mixture of phosphorus oxybromide (1 mmol) and pyridine (9 mmoles) was added to the suitable N-methyl-2-alkylindole (3.8 mmoles) under nitrogen. The reaction mixture was heated at 90°C under stirring for 18 h, then diluted with dichloromethane and the resulting solution exhaustively extracted with a 1N HCl solution. The organic layer was washed with H 2 O, dried over Na 2 SO 4 and evaporated to dryness to give a residue which was chromatographed on a silica gel column to separate the phosphine oxide 1 from unreacted N-methyl-2-alkylindole, which was eluted first.
Nature Chemistry
A key approach for designing bioinspired machines is to transfer concepts from nature to man-made... more A key approach for designing bioinspired machines is to transfer concepts from nature to man-made structures by integrating biomolecules into artificial mechanical systems. This strategy allows the conversion of molecular information into macroscopic action. Here, we describe the design and dynamic behaviour of hybrid bioelectrochemical swimmers that move spontaneously at the air–water interface. Their motion is governed by the diastereomeric interactions between immobilized enantiopure oligomers and the enantiomers of a chiral probe molecule present in solution. These dynamic bipolar systems are able to convert chiral information present at the molecular level into enantiospecific macroscopic trajectories. Depending on the enantiomer in solution, the swimmers will move clockwise or anticlockwise; the concept can also be used for the direct visualization of the degree of enantiomeric excess by analysing the curvature of the trajectories. Deciphering in such a straightforward way the enantiomeric ratio could be useful for biomedical applications, for the read-out of food quality or as a more general analogue of polarimetric measurements. Self-propelled artificial chemical swimmers have previously been developed for chemical sensing. Now, hybrid bioelectrochemical swimmers, capable of translating chiral molecular information into macroscopic motion, have been developed. Diastereomeric interactions between enantiopure oligomers immobilized on the swimmer and a chiral molecule present in solution control the trajectory of the device.
European Journal of Organic Chemistry