A5015502281- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Molecular Junctions and Nanostructures
- Quantum and electron transport phenomena
- Organic Electronics and Photovoltaics
- Force Microscopy Techniques and Applications
- Surface Chemistry and Catalysis
- Graphene research and applications
- Electrochemical Analysis and Applications
- Advancements in Battery Materials
- Lipid Membrane Structure and Behavior
- Surface and Thin Film Phenomena
- Organic Light-Emitting Diodes Research
- Advanced Battery Materials and Technologies
- Advanced biosensing and bioanalysis techniques
- Quantum Dots Synthesis And Properties
- Advanced Battery Technologies Research
- Advanced Physical and Chemical Molecular Interactions
- Synthesis and properties of polymers
- Machine Learning in Materials Science
- Silicone and Siloxane Chemistry
- Electrohydrodynamics and Fluid Dynamics
- Nanopore and Nanochannel Transport Studies
- Advanced Polymer Synthesis and Characterization
- Tribology and Wear Analysis
University of Liverpool
2015-2023
The Faraday Institution
2022
Liverpool Hospital
2016-2021
Universidad de Zaragoza
2019
University of Alicante
2013-2017
University of Babylon
2016
Durham University
2015
Xiamen University
2015
The University of Western Australia
2015
Electrochemical gating at the single molecule level of viologen molecular bridges in ionic liquids is examined. Contrary to previous data recorded aqueous electrolytes, a clear and sharp peak conductance versus electrochemical potential obtained liquids. These are rationalized terms two-step model for charge transport across redox bridge. In this gate coupling liquid found be fully effective with modeled parameter, ξ, unity. This compares much lower parameter 0.2 equivalent system. study...
The local molecular environment is a critical factor which should be taken into account when measuring single-molecule electrical properties in condensed media or the design of future electronic single molecule sensing devices. Supramolecular interactions can used to control assemblies and have been create microenvironments, for instance, chemical reactions. Here, we use supramolecular microenvironments influence conductance wires. Cucurbit[8]uril (CB[8]) with large hydrophobic cavity was...
Revealing how formation protocols influence the properties of solid-electrolyte interphase (SEI) on Si electrodes is key to developing next generation Li-ion batteries. SEI understanding is, however, limited by low-throughput nature conventional characterisation techniques. Herein, correlative scanning electrochemical cell microscopy (SECCM) and shell-isolated nanoparticles for enhanced Raman spectroscopy (SHINERS) are used combinatorial screening under a broad experimental space (20 sets...
The conductance and the decay of as a function molecular length within homologous series oligoynes, Me3Si—(C≡C)n—SiMe3 (n = 2, 3, 4, or 5), is shown to depend strongly on solvent medium. Single molecule junction measurements have been made with I(s) method for each member 5) in mesitylene (MES), 1,2,4-trichlorobenzene (TCB), propylene carbonate (PC). In mesitylene, lower obtained across whole higher (β ≈ 1 nm–1). contrast, give values 0.1 0.5 nm–1 respectively). This behavior rationalized...
This Perspective highlights relationships between chemical features of metal bis(acetylide) complexes and their electrical response in a molecular junction.
The most probable single-molecule conductance of each member a series 12 conjugated molecular wires, 6 which contain either ruthenium or platinum center centrally placed within the backbone, has been determined. measurement small, positive Seebeck coefficient established that transmission through these molecules takes place by tunneling tail HOMO resonance near middle HOMO-LUMO gap in case. Despite general similarities lengths and frontier-orbital compositions, experimental computationally...
Raman analysis has been found to provide otherwise hard obtain information on inverse vulcanised polymers, including their homogeneity, sulfur rank, and unpolymerised content.
The compounds and complexes 1,4-C6 H4 (C≡C-cyclo-3-C4 H3 S)2 (2), trans-[Pt(C≡C-cyclo-3-C4 (PEt3 )2 ] (3), trans-[Ru(C≡C-cyclo-3-C4 (dppe)2 (4; dppe=1,2-bis(diphenylphosphino)ethane) {P(OEt)3 }4 (5) featuring the 3-thienyl moiety as a surface contacting group for gold electrodes have been prepared, crystallographically characterised in case of 3-5 studied metal|molecule|metal junctions by using both scanning tunnelling microscope break-junction (STM-BJ) STM-I(s) methods (measuring current...
The single-molecule conductance of metal complexes the general forms trans-Ru(C≡CArC≡CY)2(dppe)2 and trans-Pt(C≡CArC≡CY)2(PPh3)2 (Ar = 1,4-C6H2-2,5-(OC6H13)2; Y 4-C5H4N, 4-C6H4SMe) have been determined using STM I(s) technique. display high (Y M Ru (0.4 ± 0.18 nS), Pt (0.8 0.5 nS); 4-C6H5SMe, (1.4 0.4 (1.8 0.6 nS)) for molecular structures ca. 3 nm in length, which has attributed to transport processes arising from tunneling through tails LUMO states.
We have applied a new, robust and unsupervised approach to data collection, sorting analysis that provides fresh insights into the nature of single-molecule junctions. Automation tunneling current-distance (I(s)) spectroscopy facilitates collection very large sets (up 100,000 traces for single experiment), enabling comprehensive statistical interrogations with respect underlying characteristics, noise junction formation probability (JFP). frequently observe unusual low-to-high...
Oligoynes are archetypical molecular wires due to their 1-D chain of conjugated carbon atoms and ability transmit charge over long distances by coherent tunneling. However, the stability oligoyne can be an issue. Here we address this problem two stabilization methods, namely sterically shielding endgroups, rotaxination produce insulated wire. We demonstrate threading a hexayne within macrocycle form rotaxane report measurements electrical conductance single supramolecular assembly STM break...
Electrical conductance across a molecular junction is strongly determined by the anchoring group of molecule. Here we highlight unusual behavior 1,4-bis(1H-pyrazol-4-ylethynyl)benzene that exhibits unconventional current versus junction-stretching distance curves, which are peak-shaped and feature two conducting states 2.3 × 10-4 G0 3.4 G0. A combination theory experiments used to understand single-molecule junctions featuring this new group, i.e., pyrazolyl. These results demonstrate...
Nascent molecular electronic devices based on linear 'all-carbon' wires attached to gold electrodes through robust and reliable C-Au contacts are prepared via efficient in situ sequential cleavage of trimethylsilyl end groups from an oligoyne, Me3Si-(C[triple bond, length as m-dash]C)4-SiMe3 (1). In the first stage fabrication process, removal one (TMS) group presence a substrate, which ultimately serves bottom electrode, using stoichiometric fluoride-driven process gives highly-ordered...
Monitoring the precise lithium inventory of graphitic carbon electrode within Li-ion battery, in order to assess cell aging, has remained challenging. Herein, operando electrochemical Kerr-gated Raman spectroscopy measurements on microcrystalline graphite during complete insertion and extraction are reported compared conventional continuous-wave microscopy. Suppression fluorescence emission signals via use Kerr gate enabled measurement bands highly lithiated where 0.5 ≤ x 1 for LixC6. The...
The ligands 4'-(4-(methylthio)phenyl)-2,2':6',2″-terpyridine (L(1)), 4'-((4-(methylthio)phenyl)ethynyl)- 2,2':6',2″-terpyridine (L(2)), and bis(tridentate) bridging ligand 2,3,5,6-tetra(pyridine-2-yl)pyrazine (tpp) were used to prepare the complexes [Ru(L(1))2][PF6]2 ([1][PF6]2, [Ru(L(2))2][PF6]2 ([2][PF6]2), [{(L(1))Ru}(μ-tpp){Ru(L(1))}][PF6]4 ([3][PF6]4), [{(L(2))Ru}(μ-tpp){Ru(L(2))}][PF6]4 ([4][PF6]4). Crystallographically determined structures give S···S distances of up 32.0 Å in...
‘Short circuits’ to ancillary ligands in metal complex molecular wires are identified and ‘insulated wires’ presented.
The single molecule conductances of a series bis-2,2':6',2″-terpyridine complexes featuring Ru(II), Fe(II), and Co(II) metal ions trimethylsilylethynyl (Me3SiC≡C-) or thiomethyl (MeS-) surface contact groups have been determined. In the absence electrochemical gating, these behave as tunneling barriers, with conductance properties determined more by strength electrode-molecule structure "linker" than nature metal-ion redox complex.
The electrical properties of a bidentate molecule in both large area devices and at the single level have been explored exhibit conductance one order magnitude higher than that monodentate materials with same molecular skeleton.
This paper describes the syntheses of several functionalized dihydropyrene (DHP) molecular switches with different substitution patterns. Regioselective nucleophilic alkylation a 5-substituted dimethyl isophthalate allowed development workable synthetic protocol for preparation 2,7-alkyne-functionalized DHPs. Synthesis DHPs surface-anchoring groups in 2,7- and 4,9-positions is described. The structures intermediates were elucidated by X-ray single-crystal diffraction. Molecular properties...
Controlling the orientation of molecular conductors on electrode surfaces is a critical factor in development single-molecule conductors. In current study, we used scanning tunnelling microscopy-based break junction (STM-BJ) technique to explore 'bare-bones' tripodal wires, employing different anchor groups (AGs) at 'top' and 'bottom' tripod. The triarylphosphine tris(4-(methylthio)phenyl)phosphine its corresponding phosphine sulfide showed only single high conductance feature resulting 1-...
While a multitude of studies have appeared touting the use molecules as electronic components, design molecular switches is crucial for next steps in electronics. In this work, single-molecule devices incorporating spiropyrans, made using break junction techniques, are described. Linear spiropyrans with electrode-contacting groups linked by alkynyl spacers to both indoline and chromenone moieties previously provided very low conductance values, removing spacer has resulted total loss...
We studied the electrical conductance of single-molecule junctions formed from molecular wires with four anchor groups. Three tetraphenyl-aza-BODIPYs or two thiomethyl groups were synthesized, and their was measured using break-junction-STM. Using DFT based calculations these compounds shown to display a combination high low conductance, depending on molecule's connectivity in junction. A scissor correction is employed obtain corrected HOMO–LUMO gaps tight binding model (TBM) used highlight...
A detailed study of the trimethylsilylethynyl moiety, –CCSiMe<sub>3</sub> (TMSE), as an anchoring group, using a combination experiment and DFT is presented.
The introduction of methylthioethers to the molecular wire 1,4-bis(pyridylethynyl)benzene gives rise a prototypical one with multipodal surface contacting motif that do not perturb favourable electrical characteristics pyridyl group.
In this contribution pyrazole is identified as an excellent anchor group that forms high quality films under pH controlled conditions, allowing the modulation of electrical properties with a more efficient electronic coupling in basic conditions.