Search or filter publications

Filter by type:

Filter by publication type

Filter by year:

to

Results

  • Showing results for:
  • Reset all filters

Search results

  • Journal article
    Hamill JM, Ismael A, Al-Jobory A, Bennett TLR, Alshahrani M, Wang X, Akers-Douglas M, Wilkinson LA, Robinson BJ, Long NJ, Lambert C, Albrecht Tet al., 2023,

    Quantum interference and contact effects in the thermoelectric performance of anthracene-based molecules

    , The Journal of Physical Chemistry C: Energy Conversion and Storage, Optical and Electronic Devices, Interfaces, Nanomaterials, and Hard Matter, Vol: 127, Pages: 7484-7491, ISSN: 1932-7447

    We report on the single-molecule electronic and thermoelectric properties of strategically chosen anthracene-based molecules with anchor groups capable of binding to noble metal substrates, such as gold and platinum. Specifically, we study the effect of different anchor groups, as well as quantum interference, on the electric conductance and the thermopower of gold/single-molecule/gold junctions and generally find good agreement between theory and experiments. All molecular junctions display transport characteristics consistent with coherent transport and a Fermi alignment approximately in the middle of the highest occupied molecular orbital/lowest unoccupied molecular orbital gap. Single-molecule results are in agreement with previously reported thin-film data, further supporting the notion that molecular design considerations may be translated from the single- to many-molecule devices. For combinations of anchor groups where one binds significantly more strongly to the electrodes than the other, the stronger anchor group appears to dominate the thermoelectric behavior of the molecular junction. For other combinations, the choice of electrode material can determine the sign and magnitude of the thermopower. This finding has important implications for the design of thermoelectric generator devices, where both n- and p-type conductors are required for thermoelectric current generation.

  • Journal article
    Long NJ, Bhargava S, 2022,

    Professor Edward Abel, FRSC, CBE (1931-2021)

    , DALTON TRANSACTIONS, Vol: 51, Pages: 16781-16783, ISSN: 1477-9226
  • Journal article
    Bourke S, Urbano L, Midson MM, Olona A, Qazi-Choudhry B, Panamarova M, Valderrama F, Long NJ, Dailey L-A, Green Met al., 2022,

    Nearly monodispersed, emission-tuneable conjugated polymer nanoparticles

    , SENSORS & DIAGNOSTICS, Vol: 1, Pages: 1185-1188
  • Journal article
    Cooper SM, Siakalli C, White AJP, Frei A, Miller PW, Long NJet al., 2022,

    Synthesis and anti-microbial activity of a new series of bis(diphosphine) rhenium(v) dioxo complexes

    , DALTON TRANSACTIONS, Vol: 51, Pages: 12791-12795, ISSN: 1477-9226
  • Journal article
    Wilkinson LA, Bennett TLR, Grace IM, Hamill J, Wang X, Au-Yong S, Ismael A, Jarvis SP, Hou S, Albrecht T, Cohen LF, Lambert C, Robinson BJ, Long NJet al., 2022,

    Assembly, structure and thermoelectric properties of 1,1 '-dialkynylferrocene 'hinges'

    , Chemical Science, Vol: 13, Pages: 8380-8387, ISSN: 2041-6520

    Dialkynylferrocenes exhibit attractive electronic and rotational features that make them ideal candidates for use in molecular electronic applications. However previous works have primarily focussed on single-molecule studies, with limited opportunities to translate these features into devices. In this report, we utilise a variety of techniques to examine both the geometric and electronic structure of a range of 1,1′-dialkynylferrocene molecules, as either single-molecules, or as self-assembled monolayers. Previous single molecule studies have shown that similar molecules can adopt an ‘open’ conformation. However, in this work, DFT calculations, STM-BJ experiments and AFM imaging reveal that these molecules prefer to occupy a ‘hairpin’ conformation, where both alkynes point towards the metal surface. Interestingly we find that only one of the terminal anchor groups binds to the surface, though both the presence and nature of the second alkyne affect the thermoelectric properties of these systems. First, the secondary alkyne acts to affect the position of the frontier molecular orbitals, leading to increases in the Seebeck coefficient. Secondly, theoretical calculations suggested that rotating the secondary alkyne away from the surface acts to modulate thermoelectric properties. This work represents the first of its kind to examine the assembly of dialkynylferrocenes, providing valuable information about both their structure and electronic properties, as well as unveiling new ways in which both of these properties can be controlled.

  • Journal article
    Frei A, Rigby A, Yue TTC, Firth G, Ma MT, Long NJet al., 2022,

    To chelate thallium(i) - synthesis and evaluation of Kryptofix-based chelators for Tl-201

    , DALTON TRANSACTIONS, Vol: 51, Pages: 9039-9048, ISSN: 1477-9226
  • Journal article
    Cooper SM, White AJP, Eykyn TR, Ma MT, Miller PW, Long NJet al., 2022,

    N-centered tripodal phosphine Re(V) and Tc(V) oxo complexes: revisiting a [3+2] mixed-ligand approach

    , Inorganic Chemistry: including bioinorganic chemistry, Vol: 61, Pages: 8000-8014, ISSN: 0020-1669

    N-Triphos derivatives (NP3R, R = alkyl, aryl) and asymmetric variants (NP2RXR′, R′ = alkyl, aryl, X = OH, NR2, NRR′) are an underexplored class of tuneable, tripodal ligands in relation to the coordination chemistry of Re and Tc for biomedical applications. Mixed-ligand approaches are a flexible synthetic route to obtain Tc complexes of differing core structures and physicochemical properties. Reaction of the NP3Ph ligand with the Re(V) oxo precursor [ReOCl3(PPh3)2] generated the bidentate complex [ReOCl3(κ2-NP2PhOHAr)], which possesses an unusual AA’BB’XX’ spin system with a characteristic second-order NMR lineshape that is sensitive to the bi- or tridentate nature of the coordinating diphosphine unit. The use of the asymmetric NP2PhOHAr ligand resulted in the formation of both bidentate and tridentate products depending on the presence of base. The tridentate Re(V) complex [ReOCl2(κ3-NP2PhOAr)] has provided the basis of a new reactive “metal-fragment” for further functionalization in [3 + 2] mixed-ligand complexes. The synthesis of [3 + 2] complexes with catechol-based π-donors could also be achieved under one-pot, single-step conditions from Re(V) oxo precursors. Analogous complexes can also be synthesized from suitable 99Tc(V) precursors, and these complexes have been shown to exhibit highly similar structural properties through spectroscopic and chromatographic analysis. However, a tendency for the {MVO}3+ core to undergo hydrolysis to the {MVO2}+ core has been observed both in the case of M = Re and markedly for M = 99Tc complexes. It is likely that controlling this pathway will be critical to the generation of further stable Tc(V) derivatives.

  • Journal article
    Bennett TLR, Alshammari M, Au-Yong S, Almutlg A, Wang X, Wilkinson LA, Albrecht T, Jarvis SP, Cohen LF, Ismael A, Lambert CJ, Robinson BJ, Long NJet al., 2022,

    Multi-component self-assembled molecular-electronic films: towards new high-performance thermoelectric systems

    , Chemical Science, Vol: 13, Pages: 5176-5185, ISSN: 2041-6520

    The thermoelectric properties of parallel arrays of organic molecules on a surface offer the potential for large-area, flexible, solution processed, energy harvesting thin-films, whose room-temperature transport properties are controlled by quantum interference (QI). Recently, it has been demonstrated that constructive QI (CQI) can be translated from single molecules to self-assembled monolayers (SAMs), boosting both electrical conductivities and Seebeck coefficients. However, these CQI-enhanced systems are limited by rigid coupling of the component molecules to metallic electrodes, preventing the introduction of additional layers which would be advantageous for their further development. These rigid couplings also limit our ability to suppress the transport of phonons through these systems, which could act to boost their thermoelectric output, without comprising on their impressive electronic features. Here, through a combined experimental and theoretical study, we show that cross-plane thermoelectricity in SAMs can be enhanced by incorporating extra molecular layers. We utilize a bottom-up approach to assemble multi-component thin-films that combine a rigid, highly conductive ‘sticky’-linker, formed from alkynyl-functionalised anthracenes, and a ‘slippery’-linker consisting of a functionalized metalloporphyrin. Starting from an anthracene-based SAM, we demonstrate that subsequent addition of either a porphyrin layer or a graphene layer increases the Seebeck coefficient, and addition of both porphyrin and graphene leads to a further boost in their Seebeck coefficients. This demonstration of Seebeck-enhanced multi-component SAMs is the first of its kind and presents a new strategy towards the design of thin-film thermoelectric materials.

  • Journal article
    Sheppard SA, Bennett TLR, Long NJ, 2022,

    Development and Characterisation of Highly Conjugated Functionalised Ferrocenylene Macrocycles

    , EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Vol: 2022, ISSN: 1434-1948
  • Journal article
    Li Z, Li B, Wu X, Sheppard SA, Zhang S, Gao D, Long NJ, Zhu Zet al., 2022,

    Organometallic-functionalized interfaces for highly efficient inverted perovskite solar cells

    , SCIENCE, Vol: 376, Pages: 416-+, ISSN: 0036-8075
  • Journal article
    Baker CA, Romain C, Long NJ, 2021,

    Cation-π interactions enabling hard/soft Ti/Ag heterobimetallic cooperativity in lactide ring-opening polymerisation

    , CHEMICAL COMMUNICATIONS, Vol: 57, Pages: 12524-12527, ISSN: 1359-7345
  • Journal article
    Braga M, Leow CH, Gil JH, Teh JH, Carroll L, Long NJ, Tang M-X, Aboagye EOet al., 2021,

    Investigating CXCR4 expression of tumor cells and the vascular compartment: A multimodal approach

    , PLoS One, Vol: 16, Pages: 1-21, ISSN: 1932-6203

    The C-X-C chemokine receptor 4 (CXCR4) is G protein-coupled receptor that upon binding to its cognate ligand, can lead to tumor progression. Several CXCR4-targeted therapies are currently under investigation, and with it comes the need for imaging agents capable of accurate depiction of CXCR4 for therapeutic stratification and monitoring. PET agents enjoy the most success, but more cost-effective and radiation-free approaches such as ultrasound (US) imaging could represent an attractive alternative. In this work, we developed a targeted microbubble (MB) for imaging of vascular CXCR4 expression in cancer. A CXCR4-targeted MB was developed through incorporation of the T140 peptide into the MB shell. Binding properties of the T140-MB and control, non-targeted MB (NT-MB) were evaluated in MDA-MB-231 cells where CXCR4 expression was knocked-down (via shRNA) through optical imaging, and in the lymphoma tumor models U2932 and SuDHL8 (high and low CXCR4 expression, respectively) by US imaging. PET imaging of [18F]MCFB, a tumor-penetrating CXCR4-targeted small molecule, was used to provide whole-tumor CXCR4 readouts. CXCR4 expression and microvessel density were performed by immunohistochemistry analysis and western blot. T140-MB were formed with similar properties to NT-MB and accumulated sensitively and specifically in cells according to their CXCR4 expression. In NOD SCID mice, T140-MB persisted longer in tumors than NT-MB, indicative of target interaction, but showed no difference between U2932 and SuDHL8. In contrast, PET imaging with [18F]MCFB showed a marked difference in tumor uptake at 40–60 min post-injection between the two tumor models (p<0.05). Ex vivo analysis revealed that the large differences in CXCR4 expression between the two models are not reflected in the vascular compartment, where the MB are restricted; in fact, microvessel density and CXCR4 expression in the vasculature was comparable between U2932 and SuDHL8 tumors. In conclusion, we success

  • Journal article
    Osborne BE, Yue TTC, Waters ECT, Baark F, Southworth R, Long NJet al., 2021,

    Synthesis and <i>ex vivo</i> biological evaluation of gallium-68 labelled NODAGA chelates assessing cardiac uptake and retention

    , DALTON TRANSACTIONS, Vol: 50, Pages: 14695-14705, ISSN: 1477-9226
  • Journal article
    Teh JH, Braga M, Allott L, Barnes C, Hernandez-Gil J, Tang M-X, Aboagye EO, Long NJet al., 2021,

    A kit-based aluminium-[F-18]fluoride approach to radiolabelled microbubbles

    , Chemical Communications, Vol: 57, Pages: 11677-11680, ISSN: 1359-7345

    The production of 18F-labelled microbubbles (MBs) via the aluminium-[18F]fluoride ([18F]AlF) radiolabelling method and facile inverse-electron-demand Diels–Alder (IEDDA) ‘click’ chemistry is reported. An [18F]AlF-NODA-labelled tetrazine was synthesised in excellent radiochemical yield (>95% RCY) and efficiently conjugated to a trans-cyclooctene (TCO) functionalised phospholipid (40–50% RCY), which was incorporated into MBs (40–50% RCY). To demonstrate the potential of producing 18F-labelled MBs for clinical studies, we also describe a kit-based approach which is amenable for use in a hospital radiopharmacy setting.

  • Journal article
    Walter ERH, Cooper SM, Boyle JJ, Long NJet al., 2021,

    Enzyme-activated probes in optical imaging: a focus on atherosclerosis

    , DALTON TRANSACTIONS, Vol: 50, Pages: 14486-14497, ISSN: 1477-9226

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://www.imperial.ac.uk:80/respub/WEB-INF/jsp/search-t4-html.jsp Request URI: /respub/WEB-INF/jsp/search-t4-html.jsp Query String: id=242&limit=15&resgrpMemberPubs=true&resgrpMemberPubs=true&page=2&respub-action=search.html Current Millis: 1739463930200 Current Time: Thu Feb 13 16:25:30 GMT 2025

Contact

Professor Nick Long
Email: n.long@imperial.ac.uk
Telephone: +44 (0)20 7594 5781

Location

501J
Molecular Sciences Research Hub
White City Campus

Download Nick Long's CV [PDF, 0.4MB]