Results
- Showing results for:
- Reset all filters
Search results
-
Journal articleParker D, Long NJ, Faulkner S, 2017,
Challenges for chemistry in molecular imaging
, Philosophical Transactions of the Royal Society A. Mathematical, Physical and Engineering Sciences, Vol: 375, ISSN: 1364-503X -
Journal articleLeber R, Wilson LE, Robaschik P, et al., 2017,
High Vacuum Deposition of Biferrocene Thin Films on Room Temperature Substrates
, Chemistry of Materials, Vol: 29, Pages: 8663-8669, ISSN: 0897-4756Metallocenes are a promising candidate for future spintronic devices due to their versatile and tunable magnetic properties. However, single metallocenes, e.g., ferrocene, sublimate below room temperature, and therefore the implementation for future applications is challenging. Here, a method to prepare biferrocene thin films using organic molecular beam deposition (OMBD) is presented, and the effect of substrate and deposition rate on the film structure and morphology as well as its chemical and magnetic properties is investigated. On Kapton and Si substrates, biferrocene interacts only weakly with the substrate, and distinct grains scattered over the surface are observed. By incorporating a 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) seeding layer and depositing biferrocene at high deposition rates of 1.0 Å s–1, it is possible to achieve a well-ordered densely packed film. With spintronic applications in mind, the magnetic properties of the thin films are characterized using superconducting quantum interference device (SQUID) magnetometry. Whereas initial SQUID measurements show weak ferromagnetic behavior up to room temperature due to oxidized molecule fragments, measurements of biferrocene on PTCDA capped with LiF show the diamagnetic behavior expected of biferrocene. Through the successful deposition of biferrocene thin films and the ability to control the spin state, these results demonstrate a first step toward metallocene-based spintronics.
-
Conference paperZhang G, Lin S, Leow CH, et al., 2017,
Acoustic Response of Targeted Nanodroplets Post-Activation using High Frame Rate Imaging
, IEEE International Ultrasonics Symposium (IUS), Publisher: IEEE, ISSN: 1948-5719 -
Journal articleGallo J, Harriss BI, Hernandez-Gil J, et al., 2017,
Probing T-1-T-2 interactions and their imaging implications through a thermally responsive nanoprobe
, Nanoscale, Vol: 9, Pages: 11318-11326, ISSN: 2040-3364The complex and specialised diagnostic process through magnetic resonance imaging (MRI) could be simplified with the implementation of dual T1–T2 contrast agents. T1- and T2-weighted MR are compatible modalities, and co-acquisition of contrast enhanced images in both T1 and T2 will drastically reduce artefacts and provide double-checked results. To date, efforts in the development of dual MRI probes have provided inconsistent results. Here we present the preparation and relaxometric study of a dual T1–T2 MRI probe based on superparamagnetic nanoparticles, paramagnetic Gd3+ chelates and pNIPAM (poly(N-isopropylacrylamide)), in which the distance between paramagnetic and superparamagnetic species can be modulated externally via temperature variations. Such a probe alleviates traditional nanotechnology limitations (e.g. batch to batch variability) as comparisons can be established within a single probe.
-
Journal articleAl-Owaedi OA, Bock S, Milan DC, et al., 2017,
Insulated molecular wires: inhibiting orthogonal contacts in metal complex based molecular junctions
, Nanoscale, Vol: 9, Pages: 9902-9912, ISSN: 2040-3364Metal complexes are receiving increased attention as molecular wires in fundamental studies of the transport properties of metal|molecule|metal junctions. In this context we report the single-molecule conductance of a systematic series of d8 square-planar platinum(II) trans-bis(alkynyl) complexes with terminal trimethylsilylethynyl (C[triple bond, length as m-dash]CSiMe3) contacting groups, e.g. trans-Pt{C[triple bond, length as m-dash]CC6H4C[triple bond, length as m-dash]CSiMe3}2(PR3)2 (R = Ph or Et), using a combination of scanning tunneling microscopy (STM) experiments in solution and theoretical calculations using density functional theory and non-equilibrium Green's function formalism. The measured conductance values of the complexes (ca. 3–5 × 10−5G0) are commensurate with similarly structured all-organic oligo(phenylene ethynylene) and oligo(yne) compounds. Based on conductance and break-off distance data, we demonstrate that a PPh3 supporting ligand in the platinum complexes can provide an alternative contact point for the STM tip in the molecular junctions, orthogonal to the terminal C[triple bond, length as m-dash]CSiMe3 group. The attachment of hexyloxy side chains to the diethynylbenzene ligands, e.g. trans-Pt{C[triple bond, length as m-dash]CC6H2(Ohex)2C[triple bond, length as m-dash]CSiMe3}2(PPh3)2 (Ohex = OC6H13), hinders contact of the STM tip to the PPh3 groups and effectively insulates the molecule, allowing the conductance through the full length of the backbone to be reliably measured. The use of trialkylphosphine (PEt3), rather than triarylphosphine (PPh3), ancillary ligands at platinum also eliminates these orthogonal contacts. These results have significant implications for the future design of organometallic complexes for studies in molecular junctions.
-
Journal articleWilson LE, Hassenrück C, Winter RF, et al., 2017,
Ferrocene‐ and Biferrocene‐Containing Macrocycles towards Single‐Molecule Electronics
, Angewandte Chemie, Vol: 129, Pages: 6942-6946, ISSN: 0044-8249<jats:title>Abstract</jats:title><jats:p>Cyclic multiredox centered systems are currently of great interest, with new compounds being reported and developments made in understanding their behavior. Efficient, elegant, and high‐yielding (for macrocyclic species) synthetic routes to two novel alkynyl‐conjugated multiple ferrocene‐ and biferrocene‐containing cyclic compounds are presented. The electronic interactions between the individual ferrocene units have been investigated through electrochemistry, spectroelectrochemistry, density functional theory (DFT), and crystallography to understand the effect of cyclization on the electronic properties and structure.</jats:p>
-
Journal articleLong NJ, albrecht T, wilson L, et al., 2017,
Ferrocene- and biferrocene-containing macrocycles towards single molecule electronics
, Angewandte Chemie-International Edition, Vol: 56, Pages: 6838-6824, ISSN: 1521-3773Cyclic multiredox centered systems are currently of great interest, with new compounds being reported and developments made in understanding their behavior. Efficient, elegant, and high-yielding (for macrocyclic species) synthetic routes to two novel alkynyl-conjugated multiple ferrocene- and biferrocene-containing cyclic compounds are presented. The electronic interactions between the individual ferrocene units have been investigated through electrochemistry, spectroelectrochemistry, density functional theory (DFT), and crystallography to understand the effect of cyclization on the electronic properties and structure.
-
Journal articleLi H, Harriss BI, Phinikaridou A, et al., 2017,
Gadolinium and Platinum in Tandem: Real-time Multi-Modal Monitoring of Drug Delivery by MRI and Fluorescence Imaging.
, Nanotheranostics, Vol: 1, Pages: 186-195, ISSN: 2206-7418A novel dual-imaging cisplatin-carrying molecular cargo capable of performing simultaneous optical and MR imaging is reported herein. This long-lasting MRI contrast agent (r1 relaxivity of 23.4 mM(-1)s(-1) at 3T, 25 (o)C) is a photo-activated cisplatin prodrug (PtGdL) which enables real-time monitoring of anti-cancer efficacy. PtGdL is a model for monitoring the drug delivery and anti-cancer efficacy by MRI with a much longer retention time (24 hours) in several organs such as renal cortex and spleen than GdDOTA and its motif control GdL. Upon complete release of cisplatin, all PtGdL is converted to GdL enabling subsequent MRI analyses of therapy efficacy within its reasonably short clearance time of 4 hours. There is also responsive fluorescence enhancement for monitoring by photon-excitation.
-
Conference paperMcCluskey S, Plisson C, Long N, et al., 2017,
Preclinical evaluation of [<SUP>18</SUP>F]Mitophos_07 as an imaging agent for doxorubicin induced cardiotoxicity
, Annual Meeting of the Society-of-Nuclear-Medicine-and-Molecular-Imaging (SNMMI), Publisher: SOC NUCLEAR MEDICINE INC, ISSN: 0161-5505 -
Conference paperMccluskey S, Plisson C, Tate E, et al., 2017,
Preclinical evaluation of [<SUP>18</SUP>F]Mitophos_07 as an imaging agent for doxorubicin-induced cardiotoxicity
, Publisher: WILEY, Pages: S72-S72, ISSN: 0362-4803 -
Journal articleLin S, Shah A, Hernández-Gil J, et al., 2017,
Optically and acoustically triggerable sub-micron phase-change contrast agents for enhanced photoacoustic and ultrasound imaging
, Photoacoustics, Vol: 6, Pages: 26-36, ISSN: 2213-5979We demonstrate a versatile phase-change sub-micron contrast agent providing three modes of contrast enhancement: 1) photoacoustic imaging contrast, 2) ultrasound contrast with optical activation, and 3) ultrasound contrast with acoustic activation. This agent, which we name 'Cy-droplet', has the following novel features. It comprises a highly volatile perfluorocarbon for easy versatile activation, and a near-infrared optically absorbing dye chosen to absorb light at a wavelength with good tissue penetration. It is manufactured via a 'microbubble condensation' method. The phase-transition of Cy-droplets can be optically triggered by pulsed-laser illumination, inducing photoacoustic signal and forming stable gas bubbles that are visible with echo-ultrasound in situ. Alternatively, Cy-droplets can be converted to microbubble contrast agents upon acoustic activation with clinical ultrasound. Potentially all modes offer extravascular contrast enhancement because of the sub-micron initial size. Such versatility of acoustic and optical 'triggerability' can potentially improve multi-modality imaging, molecularly targeted imaging and controlled drug release.
-
Conference paperWilson L, Albrecht T, Long N, 2017,
Delocalised chains and rings of ferrocenes
, 253rd National Meeting of the American-Chemical-Society (ACS) on Advanced Materials, Technologies, Systems, and Processes, Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727 -
Conference paperCoakley E, Long N, 2017,
Dual-modal MR/NIR fluorescent probes for zinc sensing applications
, 253rd National Meeting of the American-Chemical-Society (ACS) on Advanced Materials, Technologies, Systems, and Processes, Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727 -
Conference paperColeman C, Williams C, Long N, 2017,
Asymmetric hybrid salen/phosphasalen initiators for the iso-selective ring-opening polymerisation of rac-lactide
, 253rd National Meeting of the American-Chemical-Society (ACS) on Advanced Materials, Technologies, Systems, and Processes, Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727 -
Journal articleAnders D, Bongarzone S, Gee AD, et al., 2017,
Electrochemical [11C]CO2 to [11C]CO conversion for PET imaging
, Chemical Communications (London), Vol: 53, Pages: 2982-2985, ISSN: 0009-241XThe development of a novel electrochemical methodology to generate carbon-11 carbon monoxide ([11C]CO) from cyclotron-produced carbon-11 carbon dioxide ([11C]CO2) using Ni(cyclam) and Zn(cyclen) complexes is described. This methodology allows up to 10% yields of [11C]CO from [11C]CO2. Produced [11C]CO was subsequently converted to [11C]N-benzylbenzamide under mild conditions with a radiochemical purity (RCP) of >98%.
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.
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
