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Benincori T, Arnaboldi S, Magni M, Grecchi S, Cirilli R, Fontanesi C, Mussini PR. Highlighting spin selectivity properties of chiral electrode surfaces from redox potential modulation of an achiral probe under an applied magnetic field. Chem Sci 2019; 10:2750-2757. [PMID: 30996993 PMCID: PMC6419932 DOI: 10.1039/c8sc04126a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 01/04/2019] [Indexed: 12/26/2022] Open
Abstract
Impressive spin-related effects are observed in cyclic voltammetry (CV) experiments performed under an applied magnetic field on a non-ferromagnetic electrode modified with a thin electroactive oligothiophene film, either "inherently chiral" or featuring chiral pendants with stereogenic centres. When flipping the magnet's north/south orientation, the CV peaks of two achiral, chemically reversible Fe(iii)/Fe(ii) redox couples in aqueous or organic solution undergo impressive potential shifts (up to nearly 0.5 V depending on protocol conditions), specularly by changing the film's (R)- or (S)-configuration. The magnitude of the potential shift decreases upon increasing both the polymer film thickness and the distance between the permanent magnet and the electrode surface. Such unprecedented spin-related redox potential modulation, obtained in the absence of a magnetic electrode acting as a spin injector, provides striking evidence (as well as an attractive evaluation criterion) of the spin selectivity properties of chiral thin films.
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Capelli R, Da Como E, Kociok-Köhn G, Fontanesi C, Verna A, Pasquali L. Quantitative resonant soft x-ray reflectivity from an organic semiconductor single crystal. J Chem Phys 2019; 150:094707. [DOI: 10.1063/1.5080800] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Mishra S, Poonia VS, Fontanesi C, Naaman R, Fleming AM, Burrows CJ. Effect of Oxidative Damage on Charge and Spin Transport in DNA. J Am Chem Soc 2018; 141:123-126. [PMID: 30541275 DOI: 10.1021/jacs.8b12014] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A Hall device was used for measuring spin polarization on electrons that are either reorganized within the molecules or transmitted through the self-assembled monolayers of DNA adsorbed on the device surface. We were able to observe spin-dependent charge polarization and charge transport through double-stranded DNA of various lengths and through double-stranded DNA containing oxidative damage. We found enhancement in the spin-dependent transport through oxidatively damaged DNA. This phenomenon can be rationalized either by assuming that the damaged DNA is characterized by a higher barrier for conduction or by charge transfer through the DNA being conducted through at least two channels, one involves the bases and is highly conductive but less spin selective, while the other pathway is mainly through the ribophosphate backbone and it is the minor one in terms of charge transmission efficiency, but it is highly spin selective.
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Gazzotti M, Arnaboldi S, Grecchi S, Giovanardi R, Cannio M, Pasquali L, Giacomino A, Abollino O, Fontanesi C. Spin-dependent electrochemistry: Enantio-selectivity driven by chiral-induced spin selectivity effect. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.08.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Fontanesi C, Capua E, Paltiel Y, Waldeck DH, Naaman R. Spin-Dependent Processes Measured without a Permanent Magnet. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1707390. [PMID: 29736985 DOI: 10.1002/adma.201707390] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 02/21/2018] [Indexed: 06/08/2023]
Abstract
A novel Hall circuit design that can be incorporated into a working electrode, which is used to probe spin-selective charge transfer and charge displacement processes, is reviewed herein. The general design of a Hall circuit based on a semiconductor heterostructure, which forms a shallow 2D electron gas and is used as an electrode, is described. Three different types of spin-selective processes have been studied with this device in the past: i) photoinduced charge exchange between quantum dots and the working electrode through chiral molecules is associated with spin polarization that creates a local magnetization and generates a Hall voltage; ii) charge polarization of chiral molecules by an applied voltage is accompanied by a spin polarization that generates a Hall voltage; and iii) cyclic voltammetry (current-voltage) measurements of electrochemical redox reactions that can be spin-analyzed by the Hall circuit to provide a third dimension (spin) in addition to the well-known current and voltage dimensions. The three studies reviewed open new doors into understanding both the spin current and the charge current in electronic materials and electrochemical processes.
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Kumar A, Capua E, Fontanesi C, Carmieli R, Naaman R. Injection of Spin-Polarized Electrons into a AlGaN/GaN Device from an Electrochemical Cell: Evidence for an Extremely Long Spin Lifetime. ACS NANO 2018; 12:3892-3897. [PMID: 29617105 DOI: 10.1021/acsnano.8b01347] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Spin-polarized electrons are injected from an electrochemical cell through a chiral self-assembled organic monolayer into a AlGaN/GaN device in which a shallow two-dimensional electron gas (2DEG) layer is formed. The injection is monitored by a microwave signal that indicates a coherent spin lifetime that exceeds 10 ms at room temperature. The signal was found to be magnetic field independent; however, it depends on the current of the injected electrons, on the length of the chiral molecules, and on the existence of 2DEG.
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Mondal PC, Fontanesi C. Electrochemistry of Metalloproteins Attached through Functional Self-Assembled Monolayers on Gold and Ferromagnetic Electrodes. Chemphyschem 2017; 19:60-66. [PMID: 29124840 DOI: 10.1002/cphc.201701018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 10/28/2017] [Indexed: 11/08/2022]
Abstract
We report the experimental results of a study of the electron-transfer processes of redox-active metalloproteins bound to mixed self-assembled monolayers (SAMs) on magnetic (nickel or ultrathin gold-coated nickel) or nonmagnetic (gold) electrodes. Metalloproteins, such as hemoglobin (Hb), Cytochrome C (Cyt C), and Cyt C oxidase, are attached through electrostatic interactions to the free carboxylate or imidazole groups present in the mixed SAMs. The formation of both mixed SAMs and SAM/metalloprotein heterostructures were confirmed by using advanced surface analysis techniques, such as polarization modulation infrared reflection absorption spectroscopy and aqueous contact angle measurements. Electrochemical measurements indicated a stronger electronic coupling between Hb and Cyt C oxidase and the mixed-SAM-coated gold or gold-coated-nickel electrodes, whereas a weaker coupling was found between the protein and the pure nickel electrode. Surface coverage and the electron-transfer rate constant were estimated from the cyclic voltammetry data.
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Kumar A, Capua E, Vankayala K, Fontanesi C, Naaman R. Magnetless Device for Conducting Three-Dimensional Spin-Specific Electrochemistry. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201708829] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Kumar A, Capua E, Vankayala K, Fontanesi C, Naaman R. Magnetless Device for Conducting Three-Dimensional Spin-Specific Electrochemistry. Angew Chem Int Ed Engl 2017; 56:14587-14590. [DOI: 10.1002/anie.201708829] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Indexed: 11/07/2022]
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35
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Sassi M, Salamone MM, Beverina L, Longoni G, Fontanesi C, Vanossi D, Cigarini L, Ruffo R. An Integrated Theoretical/Experimental Study of Quinolinic-Isoquinolinic Derivatives Acting as Reversible Electrochromes. MATERIALS (BASEL, SWITZERLAND) 2017; 10:ma10070802. [PMID: 28773162 PMCID: PMC5551845 DOI: 10.3390/ma10070802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/11/2017] [Accepted: 07/11/2017] [Indexed: 06/07/2023]
Abstract
A series of compounds, featuring an ethenylic bridge and quinoline and isoquinoline end capping units possessing systematically varied substitution patterns, were prepared as molecular materials for electrochromic applications. The different structures were optimized in order to maximize the electrochromic contrast in the visible region, mostly by achieving a completely UV-absorbing oxidized state. Density functional theory (DFT) calculations are exploited in order to rationalize the correlation between the molecular structure, the functional groups' electronic properties, and the electrochemical behavior. It is shown that the molecular planarity (i.e. ring/ring π conjugation) plays a major role in defining the mechanism of the electrochemical charge transfer reaction, while the substituent's nature has an influence on the LUMO energy. Among the compounds here studied, the (E)-10-methyl-9-(2-(2-methylisoquinolinium-1-yl)-vinyl)-1,2,3,4-tetrahydroacri-dinium trifluoromethanesulfonate derivative shows the most interesting properties as an electrochromophore.
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Benedetti L, Borsari M, Fontanesi C, Battistuzzi Gavioli G. Kinetics of compact layer formation and growth of 1,10-phenanthroline at the electrode surface. ACTA ACUST UNITED AC 2017. [DOI: 10.1051/jcp/1990871597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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37
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Mtangi W, Tassinari F, Vankayala K, Vargas Jentzsch A, Adelizzi B, Palmans ARA, Fontanesi C, Meijer EW, Naaman R. Control of Electrons' Spin Eliminates Hydrogen Peroxide Formation During Water Splitting. J Am Chem Soc 2017; 139:2794-2798. [PMID: 28132505 PMCID: PMC5330654 DOI: 10.1021/jacs.6b12971] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
The
production of hydrogen through water splitting in a photoelectrochemical
cell suffers from an overpotential that limits the efficiencies. In
addition, hydrogen-peroxide formation is identified as a competing
process affecting the oxidative stability of photoelectrodes. We impose
spin-selectivity by coating the anode with chiral organic semiconductors
from helically aggregated dyes as sensitizers; Zn-porphyrins and triarylamines.
Hydrogen peroxide formation is dramatically suppressed, while the
overall current through the cell, correlating with the water splitting
process, is enhanced. Evidence for a strong spin-selection in the
chiral semiconductors is presented by magnetic conducting (mc-)AFM
measurements, in which chiral and achiral Zn-porphyrins are compared.
These findings contribute to our understanding of the underlying mechanism
of spin selectivity in multiple electron-transfer reactions and pave
the way toward better chiral dye-sensitized photoelectrochemical cells.
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Mondal PC, Fontanesi C, Waldeck DH, Naaman R. Spin-Dependent Transport through Chiral Molecules Studied by Spin-Dependent Electrochemistry. Acc Chem Res 2016; 49:2560-2568. [PMID: 27797176 PMCID: PMC5112609 DOI: 10.1021/acs.accounts.6b00446] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
![]()
Molecular spintronics (spin + electronics), which aims to exploit
both the spin degree of freedom and the electron charge in molecular
devices, has recently received massive attention. Our recent experiments
on molecular spintronics employ chiral molecules which have the unexpected
property of acting as spin filters, by way of an effect we call “chiral-induced spin selectivity” (CISS). In this
Account, we discuss new types of spin-dependent electrochemistry measurements
and their use to probe the spin-dependent charge transport properties
of nonmagnetic chiral conductive polymers and biomolecules, such as
oligopeptides, L/D cysteine, cytochrome c, bacteriorhodopsin
(bR), and oligopeptide-CdSe nanoparticles (NPs) hybrid structures.
Spin-dependent electrochemical measurements were carried out by employing
ferromagnetic electrodes modified with chiral molecules used as the
working electrode. Redox probes were used either in solution or when
directly attached to the ferromagnetic electrodes. During the electrochemical
measurements, the ferromagnetic electrode was magnetized either with
its magnetic moment pointing “UP” or “DOWN”
using a permanent magnet (H = 0.5 T), placed underneath
the chemically modified ferromagnetic electrodes. The spin polarization
of the current was found to be in the range of 5–30%, even
in the case of small chiral molecules. Chiral films of the l- and d-cysteine tethered with a redox-active dye, toludin
blue O, show spin polarizarion that depends on the chirality. Because
the nickel electrodes are susceptible to corrosion, we explored the
effect of coating them with a thin gold overlayer. The effect of the
gold layer on the spin polarization of the electrons ejected from
the electrode was investigated. In addition, the role of the structure
of the protein on the spin selective transport was also studied as
a function of bias voltage and the effect of protein denaturation
was revealed. In addition to “dark” measurements, we
also describe photoelectrochemical measurements in which light is
used to affect the spin selective electron transport through the chiral
molecules. We describe how the excitation of a chromophore (such as
CdSe nanoparticles), which is attached to a chiral working electrode,
can flip the preferred spin orientation of the photocurrent, when
measured under the identical conditions. Thus, chirality-induced spin
polarization, when combined with light and magnetic field effects,
opens new avenues for the study of the spin transport properties of
chiral molecules and biomolecules and for creating new types of spintronic
devices in which light and molecular chirality provide new functions
and properties.
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Potticary J, Terry LR, Bell C, Papanikolopoulos AN, Christianen PCM, Engelkamp H, Collins AM, Fontanesi C, Kociok-Köhn G, Crampin S, Da Como E, Hall SR. An unforeseen polymorph of coronene by the application of magnetic fields during crystal growth. Nat Commun 2016; 7:11555. [PMID: 27161600 PMCID: PMC4866376 DOI: 10.1038/ncomms11555] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 04/07/2016] [Indexed: 11/27/2022] Open
Abstract
The continued development of novel drugs, proteins, and advanced materials strongly rely on our ability to self-assemble molecules in solids with the most suitable structure (polymorph) in order to exhibit desired functionalities. The search for new polymorphs remains a scientific challenge, that is at the core of crystal engineering and there has been a lack of effective solutions to this problem. Here we show that by crystallizing the polyaromatic hydrocarbon coronene in the presence of a magnetic field, a polymorph is formed in a β-herringbone structure instead of the ubiquitous γ-herringbone structure, with a decrease of 35° in the herringbone nearest neighbour angle. The β-herringbone polymorph is stable, preserves its structure under ambient conditions and as a result of the altered molecular packing of the crystals, exhibits significant changes to the optical and mechanical properties of the crystal.
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Parenti F, Ricciardi R, Diana R, Morvillo P, Fontanesi C, Tassinari F, Schenetti L, Minarini C, Mucci A. Polymers for application in organic solar cells: Bithiophene can work better than thienothiophene when coupled to benzodithiophene. ACTA ACUST UNITED AC 2015. [DOI: 10.1002/pola.28014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Mtangi W, Kiran V, Fontanesi C, Naaman R. Role of the Electron Spin Polarization in Water Splitting. J Phys Chem Lett 2015; 6:4916-22. [PMID: 26615833 PMCID: PMC4685426 DOI: 10.1021/acs.jpclett.5b02419] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 11/29/2015] [Indexed: 05/22/2023]
Abstract
We show that in an electrochemical cell, in which the photoanode is coated with chiral molecules, the overpotential required for hydrogen production drops remarkably, as compared with cells containing achiral molecules. The hydrogen evolution efficiency is studied comparing seven different organic molecules, three chiral and four achiral. We propose that the spin specificity of electrons transferred through chiral molecules is the origin of a more efficient oxidation process in which oxygen is formed in its triplet ground state. The new observations are consistent with recent theoretical works pointing to the importance of spin alignment in the water-splitting process.
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Cigarini L, Vanossi D, Bondioli F, Fontanesi C. A novel synthetic strategy for magnetite-type compounds. A combined experimental and DFT-computational study. Phys Chem Chem Phys 2015. [PMID: 26198092 DOI: 10.1039/c5cp01852h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The dynamics of the early stage reaction between benzyl alcohol and Fe(acetylacetonate)3 is studied by exploiting the Dynamic Reaction Coordinate (DRC) approach, at the PBE0/6-31G* level of theory. Analysis of the DRC trajectory provides a detailed molecular insight into the catalytic effect observed in the acidic reaction environment, compared to the neutral one. The presence of an additional proton in the reaction system, meant to simulate an acidic reaction environment, dramatically affects the reaction path: both by decreasing the activation energy of the complex dissociation and leading to the formation of acetone.
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Mondal PC, Fontanesi C, Waldeck DH, Naaman R. Field and chirality effects on electrochemical charge transfer rates: spin dependent electrochemistry. ACS NANO 2015; 9:3377-84. [PMID: 25752750 DOI: 10.1021/acsnano.5b00832] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
This work examines whether electrochemical redox reactions are sensitive to the electron spin orientation by examining the effects of magnetic field and molecular chirality on the charge transfer process. The working electrode is either a ferromagnetic nickel film or a nickel film that is coated with an ultrathin (5-30 nm) gold overlayer. The electrode is coated with a self-assembled monolayer that immobilizes a redox couple containing chiral molecular units, either the redox active dye toluidine blue O with a chiral cysteine linking unit or cytochrome c. By varying the direction of magnetization of the nickel, toward or away from the adsorbed layer, we demonstrate that the electrochemical current depends on the orientation of the electrons' spin. In the case of cytochrome c, the spin selectivity of the reduction is extremely high, namely, the reduction occurs mainly with electrons having their spin-aligned antiparallel to their velocity.
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Fontanesi C, Tassinari F, Parenti F, Cohen H, Mondal PC, Kiran V, Giglia A, Pasquali L, Naaman R. New one-step thiol functionalization procedure for Ni by self-assembled monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3546-3552. [PMID: 25726858 DOI: 10.1021/acs.langmuir.5b00177] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This article reports on a facile and fast strategy for the self-assembled monolayer (SAM) functionalization of nickel surfaces, employing cyclic voltammetry (CV) cycling of a suitable tailored solution containing the species to be adsorbed. Results are presented for ultrathin films formed on Ni by 1-hexadecanethiol (C16), L-cysteine (L-cys), and the poly{methyl (2R)-3-(2,2'-bithiophen-4-ylsulfanyl)-2-[(tert-butoxycarbonyl)amino]propanoate} (PCT-L) thiophene-based chiral polymer. The effective formation of high-quality ultrathin organic films on the nickel was verified both electrochemically and by exploiting typical surface characterization techniques such as contact angle, ellipsometry, atomic force microscopy (AFM), polarization modulation-infrared reflection-absorption spectroscopy (PM-IRRAS), and X-ray photoelectron spectroscopy (XPS).
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Mondal PC, Kantor-Uriel N, Mathew SP, Tassinari F, Fontanesi C, Naaman R. Chiral conductive polymers as spin filters. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:1924-1927. [PMID: 25619708 DOI: 10.1002/adma.201405249] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 12/17/2014] [Indexed: 06/04/2023]
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Tassinari F, Mathew SP, Fontanesi C, Schenetti L, Naaman R. Electric-field-driven alignment of chiral conductive polymer thin films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:4838-4843. [PMID: 24731141 DOI: 10.1021/la500657e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigated the effect of an electric field on the alignment and structural properties of thin films of a chiral polybithiophene-based conductive polymer, functionalized with a protected l-cysteine amino acid. Thin films were obtained by exploiting both drop-casting and spin-coating procedures. The electric properties, the polarized Raman spectrum, the UV-vis spectrum, and the CD spectra were measured as a function of the electric field intensity applied during film formation. It was found that beyond the enhancement of the conductivity observed when the electric field aligns the polymer, the electric field significantly affects the chiral properties and the effect depends on the method of deposition.
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Morvillo P, Diana R, Fontanesi C, Ricciardi R, Lanzi M, Mucci A, Tassinari F, Schenetti L, Minarini C, Parenti F. Low band gap polymers for application in solar cells: synthesis and characterization of thienothiophene–thiophene copolymers. Polym Chem 2014. [DOI: 10.1039/c3py01618h] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Tassinari F, Vanossi D, Mucci A, Parenti F, Fontanesi C. Regiochemistry in the electrochemical assisted grafting of glassy carbon. With focus on sterical hindrance of lateral chains in the electroreduction process of multi-functionalized bithiophene. J Electroanal Chem (Lausanne) 2013. [DOI: 10.1016/j.jelechem.2013.04.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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49
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Vanossi D, Pigani L, Seeber R, Ferrarini P, Baraldi P, Fontanesi C. Electropolymerization of ortho-phenylenediamine. Structural characterisation of the resulting polymer film and its interfacial capacitive behaviour. J Electroanal Chem (Lausanne) 2013. [DOI: 10.1016/j.jelechem.2013.04.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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50
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Tassinari F, Tancini E, Innocenti M, Schenetti L, Fontanesi C. On the hybrid glassy carbon electrode/OligoThiophene/Ag(NP) interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15505-15512. [PMID: 23083106 DOI: 10.1021/la3025777] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
GC/OligoThiophene/Ag(NP) hybrid interfaces are synthesized and characterized: GC is the glassy carbon surface; OligoThiophene stands for both an ultrathin bithiophene grafted film and a 4-Br-Bithiophene grafted polymer; Ag(NP) stands for silver nanoparticles. The hybrid interface preparation involves different steps: first, the electrode surface is functionalized through a combination of electrochemically assisted grafting (under reduction regime) and polymerization (under oxidation regime); then, silver nanoparticles are chemisorbed by dipping. In particular, an ultrathin film of grafted bithiophene can be obtained by applying one cyclic voltammetry reduction cycle (GC/BT surface), while subsequent cyclic voltammetry cycling under oxidation regime yields an immobilized 4Br-Bithiophene polymer (GC/4BrBT surface). AFM and TEM images were recorded to investigate the morphology and chemical composition of the Ag(NP). Fe(II)/Fe(III) cyclic voltammetry, Zn underpotential deposition (UPD), XPS, LA-ICP-MS, and Raman techniques were exploited to characterize both the GC/OligoThiophene and GC/OligoThiophene/Ag(NP) interfaces. Theoretical calculation, at the B3LYP/6-311G** level of the theory, enabled rationalization of the electroreduction mechanism and the Raman results.
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