Dr Emma Richards
Lecturer in Physical Chemistry
Overview
The research interests of the group focus on utilizing the powerful technique of Electron Paramagnetic Resonance (EPR) spectroscopy and associated hyperfine methodologies [e.g. Electron Nuclear Double Resonance (ENDOR), Hyperfine Sublevel Correlation Spectroscopy (HYSCORE) and Pulsed Electron Double Resonance (PELDOR)] in two main areas of activity:
- investigating electron transfer processes in condensed matter materials of importance in visible-light activated catalysis,
- elucidating the nature of transition metal active sites in metalloenzymes and bioinorganic systems.
The broad applicability of these methodologies is evidenced by their use in the wide range of chemical, physical, biological and earth sciences. We welcome enquiries from researchers seeking to develop collaborative opportunities.
The group is equipped with both continuous wave (CW) and Pulsed EPR/ENDOR facilities at X- and Q-band frequencies.
For more information, click on the 'Research' tab above.
Biography
BSc(Hons) Natural Sciences with study in Industry, (Infineum, Oxfordshire; 1st Class Honours, Accenture prize for highest graduating student), University of Bath (1999 – 2003); PhD, University of Wales, Cardiff (2003 – 2007, Prof D. Murphy); Welsh Livery Guild Trust Travel Scholarship, University of Antwerp, (July 2008); Postdoctoral Research Associate, Cardiff University (2007 – 2015); Appointed Cardiff University Research Fellow 2015.
Member of the Royal Society of Chemistry; Fellow of the Higher Education Academy
Publications
2021
- Wu, Q.et al. 2021. Inhibit the formation of toxic methylphenolic by-products in photo-decomposition of formaldehyde-toluene/xylene mixtures by Pd cocatalyst on TiO2. Applied Catalysis B: Environmental 291, article number: 120118. (10.1016/j.apcatb.2021.120118)
- Woof, C. R.et al. 2021. Iron catalyzed double bond isomerization: evidence for an Fe I /Fe III catalytic cycle. Chemistry - A European Journal 27(19), pp. 5972-5977. (10.1002/chem.202004980)
- Dasgupta, A.et al. 2021. Site-selective Csp3–Csp/Csp3–Csp2 cross-coupling reactions using frustrated Lewis pairs. Journal of the American Chemical Society 143(11), pp. 4451-4464. (10.1021/jacs.1c01622)
- Folli, A.et al. 2021. Probing the structure of copper(II)-casiopeina type coordination complexes [Cu(O-O)(N-N)]+ by EPR and ENDOR spectroscopy. Journal of Catalysis 394, pp. 220-227. (10.1016/j.jcat.2020.07.016)
- Ayan, D., Richards, E. and Melen, R. 2021. Frustrated radical pairs: insights from EPR spectroscopy. Angewandte Chemie International Edition 60(1), pp. 53-65. (10.1002/anie.202010633)
2020
- Soltani, Y.et al. 2020. Radical reactivity of frustrated Lewis pairs with diaryl esters. Cell Reports Physical Science 1(2) (10.1016/j.xcrp.2020.100016)
- Folli, A.et al. 2020. A novel dual mode X-band EPR resonator for rapid in situ microwave heating. Journal of Magnetic Resonance 310, article number: 106644. (10.1016/j.jmr.2019.106644)
- Wilson, A. S. S.et al. 2020. Calcium hydride reduction of polycyclic aromatic hydrocarbons. Angewandte Chemie International Edition 59(3), pp. 1232-1237. (10.1002/anie.201913895)
2019
- Richards, E., Murphy, D. M. and Che, M. 2019. An EPR characterisation of stable and transient reactive oxygen species formed under radiative and non-radiative conditions. Research on Chemical Intermediates 45(12), pp. 5763-5779. (10.1007/s11164-019-04001-0)
- Luckham, S. L. J.et al. 2019. Unravelling the photochemical transformations of chromium(I) 1,3 Bis(diphenylphosphino), [Cr(CO)4(dppp)]+, by EPR spectroscopy. Organometallics 38(12), pp. -. (10.1021/acs.organomet.9b00226)
- McGuire, J.et al. 2019. Enabling single qubit addressability in a molecular semiconductor comprising gold-supported organic radicals. Chemical Science 10(5), pp. 1483-1491. (10.1039/C8SC04500C)
- Hill, M. S.et al. 2019. Reduction of 1,3,5,7-cyclooctatetraene by a molecular calcium hydride: an even electron polarised insertion/deprotonation mechanism. Chemical Communications 55(40), pp. 5732-5735. (10.1039/C9CC02418B)
2018
- McGuire, J.et al. 2018. Ligand radicals as modular organic electron spin qubits. Chemistry - A European Journal 24(66), pp. 17598-17605. (10.1002/chem.201804165)
- Spencer, J.et al. 2018. Applications of electron paramagnetic resonance spectroscopy for interrogating catalytic systems. In: Chechik, V. and Murphy, D. M. eds. Electron Paramagnetic Resonance., Vol. 26. Royal Society of Chemistry, pp. 130-170., (10.1039/9781788013888-00130)
- Regue, M.et al. 2018. Mo-doped TiO2 photoanodes using [Ti4Mo2O8(OEt)10]2 bimetallic oxo cages as a single source precursor. Sustainable Energy & Fuels 2(12), pp. 2674-2686. (10.1039/C8SE00372F)
- Folli, A.et al. 2018. Improving the selectivity of photocatalytic NOx abatement through improved O2 reduction pathways using Ti0.909W0.091O2Nx semiconductor nanoparticles: from characterisation to photocatalytic performance. ACS Catalysis 8(8), pp. 6927-6938. (10.1021/acscatal.8b00521)
2017
- Blackaby, W. J. M.et al. 2017. Mono- and dinuclear Ni(i) products formed upon bromide abstraction from the Ni(i) ring-expanded NHC complex [Ni(6-Mes)(PPh3)Br]. Dalton Transactions 47(3), pp. 769-782. (10.1039/C7DT04187J)
- Ritterskamp, N.et al. 2017. Understanding the coordination modes of [Cu(acac)2(imidazole)n=1,2] adducts by EPR, ENDOR, HYSCORE, and DFT analysis. Inorganic Chemistry 56(19), pp. 11862-11875. (10.1021/acs.inorgchem.7b01874)
- Ould, D. M. C.et al. 2017. Investigations into the photophysical and electronic properties of pnictoles and Their pnictenium counterparts. Organometallics 37(5), pp. 712-719. (10.1021/acs.organomet.7b00564)
- Li, Y.et al. 2017. Trapping a silicon(I) radical with carbenes: a cationic cAAC-silicon(I) radical and an NHC-parent-silyliumylidene cation. Angewandte Chemie International Edition 56(26), pp. 7573-7578. (10.1002/anie.201702760)
- Constantinides, C. P.et al. 2017. Effects of Halo-substitution on 2'-Chloro-5'-halo-phenyl-1,2,3,5-dithiadiazolyl Radicals: A Crystallographic, Magnetic and EPR Case Study. Crystal Growth and Design 17(6), pp. 3017-3029. (10.1021/acs.cgd.6b01700)
2016
- Zhang, S. H.et al. 2016. Delocalized hypervalent silyl radical supported by amidinate and imino substituents. Inorganic Chemistry 56(2), pp. 701-704. (10.1021/acs.inorgchem.6b02427)
- Su, R.et al. 2016. Mechanistic insight into the interaction between a titanium dioxide photocatalyst and Pd co-catalyst for improved photocatalytic performance. ACS Catalysis 6(7), pp. 4239-4247. (10.1021/acscatal.6b00982)
- Et-Tarhouni, Z.et al. 2016. Quantifying the micellar structure formed from hydrocarbon-fluorocarbon surfactants. Colloids and Surfaces A: Physiochemical and Engineering Aspects 492, pp. 255-262. (10.1016/j.colsurfa.2015.12.015)
- Hallett, A. J.et al. 2016. Copper(II) complexes of pyridine-oxazoline (Pyox) ligands: coordination chemistry, ligand stability, and catalysis. Inorganica Chimica Acta 441, pp. 86-94. (10.1016/j.ica.2015.10.032)
- Chechik, V., Carter, E. and Murphy, D. 2016. Electron paramagnetic resonance. Oxford Chemistry Primers. Oxford: Oxford University Press.
2015
- Carter, E. and Murphy, D. M. 2015. The role of low valent transition metal complexes in homogeneous catalysis: an EPR investigation. Topics in Catalysis 58(12-13), pp. 759-768. (10.1007/s11244-015-0417-6)
- Carter, E.et al. 2015. Structure determination of bound nitrogen-based adducts with copper(ii) acetylacetonato; an EPR, ENDOR and DFT study. Physical Chemistry Chemical Physics 17(17), pp. 11445-11454. (10.1039/C5CP00559K)
- Carter, E. and Murphy, D. 2015. Homogeneous catalytic transformations investigated by EPR spectroscopy. In: Gilbert, B. C., Chechik, V. and Murphy, D. eds. Electron Paramagnetic Resonance., Vol. 24. Royal Society of Chemistry, pp. 148-193., (10.1039/9781782620280-00148)
2014
- Ambrose, L. J. A.et al. 2014. Investigating mitochondrial metabolism in contracting HL-1 cardiomyocytes following hypoxia and pharmacological HIF activation identifies HIF-dependent and independent mechanisms of regulation. Journal of Cardiovascular Pharmacology and Therapeutics 19(6), pp. 574-585. (10.1177/1074248414524480)
- Bedford, R. B.et al. 2014. Iron-catalyzed borylation of alkyl, allyl, and aryl halides: isolation of an iron(I) boryl complex. Organometallics 33(21), pp. 5940-5943. (10.1021/om500847j)
- Bedford, R. B.et al. 2014. Iron phosphine catalyzed cross-coupling of tetraorganoborates and related group 13 nucleophiles with alkyl halides. Organometallics 33(20), pp. 5767-5780. (10.1021/om500518r)
- Constantinides, C. P.et al. 2014. Weakening of the pi*-pi* dimerisation in 1,2,3,5-dithiadiazolyl radicals: structural, EPR, magnetic and computational studies of dichlorophenyl dithiadiazolyls, Cl2C6H3CNSSN. Crystengcomm 16(31), pp. 7298-7312. (10.1039/C4CE00308J)
- Bedford, R. B.et al. 2014. TMEDA in iron-catalyzed Kumada coupling: amine adduct versus homoleptic "ate" complex formation. Angewandte Chemie International Edition 53(7), pp. 1804-1808. (10.1002/anie.201308395)
2013
- Poulten, R. C.et al. 2013. Synthesis, electronic structure, and magnetism of [Ni(6-Mes)2]+: a two-coordinate nickel(I) complex stabilized by bulky N-heterocyclic carbenes. Journal of the American Chemical Society 135(37), pp. 13640-13643. (10.1021/ja407004y)
- Sharples, K. M.et al. 2013. An ENDOR and DFT analysis of hindered methyl group rotations in frozen solutions of bis(acetylacetonato)-copper(ii). Physical Chemistry Chemical Physics 15(36), pp. 15214-15222. (10.1039/c3cp52464g)
- Griffiths, P. C.et al. 2013. Self-assembled PAA-based nanoparticles as potential gene and protein delivery systems. Macromolecular Bioscience 13(5), pp. 641-649. (10.1002/mabi.201200462)
- Page, M. J.et al. 2013. Three-coordinate nickel(I) complexes stabilised by six-, seven- and eight-membered ring N-heterocyclic carbenes: synthesis, EPR/DFT studies and catalytic activity. Chemistry - a European Journal 19(6), pp. 2158-2167. (10.1002/chem.201202950)
- Bedford, R. B.et al. 2013. Simplifying iron-phosphine catalysts for cross-coupling reactions. Angewandte Chemie - International Edition 52(4), pp. 1285-1288. (10.1002/anie.201207868)
- Carter, E.et al. 2013. Formation of [Cr(CO)x(Ph2PN(iPr)PPh2)]+Structural Isomers by Reaction of Triethylaluminum with a ChromiumN,N-Bis(diarylphosphino)amine Complex [Cr(CO)4(Ph2PN(iPr)PPh2)]+: An EPR and DFT Investigation. Organometallics 32(6), pp. 1924-1931. (10.1021/om400029y)
- Mughal, S.et al. 2013. The tetratriptycenoporphyrazines revisited. Journal of Porphyrins and Phthalocyanines 17(08n09), pp. 778-784. (10.1142/S1088424613500351)
- Constantinides, C. P.et al. 2013. Spin-triplet excitons in 1,3-diphenyl-7-(fur-2-yl)-1,4-dihydro-1,2,4-benzotriazin-4-yl. Chemical Communications 49(77), pp. 8662-8664. (10.1039/c3cc44899a)
- Carter, E.et al. 2013. Structure, EPR/ENDOR and DFT characterisation of a [CuII(en)2](OTf)2 complex. Dalton Transactions 42(42), pp. 15088-15096. (10.1039/c3dt51694f)
2012
- Owen, M. E.et al. 2012. Influence of counterions on the structure of bis(oxazoline) copper(II) complexes; an EPR and ENDOR investigation. Dalton Transactions 41(36), pp. 11085-11092. (10.1039/C2DT31273E)
- Zamani, S.et al. 2012. Probing differences in binding of methylbenzylamine enantiomers to chiral cobalt(II) salen complexes. Dalton Transactions 41(22), pp. 6861-6870. (10.1039/C2DT30207A)
- Stephen, E.et al. 2012. Redox non-innocence of thioether crowns: elucidation of the electronic structure of the mononuclear Pd(III) complexes [Pd([9]aneS3)2]3+and [Pd([18]aneS6)]3+. Inorganic Chemistry 51(3), pp. 1450-1461. (10.1021/ic2017006)
- Adams, C. J.et al. 2012. Iron(I) in Negishi cross-coupling reactions. Journal of the American Chemical Society 134(25), pp. 10333-10336. (10.1021/ja303250t)
- Vinck, E.et al. 2012. Observation of an organic acid mediated spin state transition in a Co(II)-Schiff base complex: an EPR, HYSCORE, and DFT study. Inorganic Chemistry 51(15), pp. 8014-8024. (10.1021/ic300058p)
2011
- Murphy, D. M.et al. 2011. Visualizing diastereomeric interactions of chiral amine-chiral copper salen adducts by EPR spectroscopy and DFT. Inorganic Chemistry 50(15), pp. 6944-6955. (10.1021/ic200113u)
- Carter, E.et al. 2011. Structure and pulsed EPR characterization of N,N′-bis(5-tert-butylsalicylidene)-1,2-cyclohexanediamino-vanadium(IV) oxide and its adducts with propylene oxide. Dalton Transactions 40(28), pp. 7454-7462. (10.1039/c1dt10378d)
- Woodul, W. D.et al. 2011. A neutral, monomeric germanium(I) radical. Journal of the American Chemical Society 133(26), pp. 10074-10077. (10.1021/ja204344e)
- Murphy, D. M.et al. 2011. A CW-EPR, ENDOR and special TRIPLE resonance study of a novel magnesium ketyl radical. Magnetic Resonance in Chemistry 49(4), pp. 159-163. (10.1002/mrc.2721)
- Alberola, A.et al. 2011. Crystal structures, EPR and magnetic properties of 2-ClC6H4CNSSN˙ and 2,5-Cl2C6H3CNSSN˙. Chemical Communications 47(9), pp. 2532-2534. (10.1039/c0cc04296j)
- McDyre, L.et al. 2011. Intramolecular formation of a CrI(bis-arene) species via TEA activation of [Cr(CO)4(Ph2P(C3H6)PPh2)]+: sn EPR and DFT investigation. Organometallics 30(17), pp. 4505-4508. (10.1021/om2006062)
- Caretti, I.et al. 2011. Interactions of an asymmetric amine with a non-C2 symmetric Cu-salen complex: An EPR/ENDOR and HYSCORE investigation. Physical Chemistry Chemical Physics 13(45), pp. 20427-20434. (10.1039/c1cp22522g)
- Garcia, T.et al. 2011. The significance of the order of impregnation on the activity of vanadia promoted palladium-alumina catalysts for propane total oxidation. Catalysis Science & Technology 1(8), pp. 1367-1375. (10.1039/c0cy00032a)
2010
- Griffiths, P. C.et al. 2010. Interaction of an endosomolytic polyamidoamine ISA23 with vesicles mimicking intracellular membranes: A SANS/EPR study. Macromolecular Bioscience 10(8), pp. 963-973. (10.1002/mabi.201000040)
- Carter, E.et al. 2010. Probing the role of weak outer sphere interactions (H-bonds) in VO(3,5-tBu2-salophen) – Epoxide adducts by EPR, ENDOR and HYSCORE. Chemical Physics Letters 486(1-3), pp. 74-79. (10.1016/j.cplett.2009.12.066)
- Carter, E.et al. 2010. Experimental observation of spin delocalisation onto the aryl-alkynyl ligand in the complexes [Mo(C=CAr)(Ph2PCH2CH2PPh2)(η-C7H7)]+ (Ar = C6H5, C6H4-4-F; C7H7 = cycloheptatrienyl): an EPR and ENDOR investigation. Dalton Transactions 39(47), pp. 11424-11431. (10.1039/c0dt00642d)
2009
- Green, J., Carter, E. and Murphy, D. M. 2009. Interaction of molecular oxygen with oxygen vacancies on reduced TiO2: Site specific blocking by probe molecules. Chemical Physics Letters 477(4-6), pp. 340-344. (10.1016/j.cplett.2009.07.002)
- Green, J., Carter, E. and Murphy, D. M. 2009. An EPR investigation of acetonitrile reactivity with superoxide radicals on polycrystalline TiO2. Research on Chemical Intermediates 35(2), pp. 145-154. (10.1007/s11164-008-0022-4)
- Murphy, D. M.et al. 2009. Enantioselective binding of structural epoxide isomers by a chiral vanadyl salen complex: a pulsed EPR, cw-ENDOR and DFT investigation. Physical Chemistry Chemical Physics 11(31), pp. 6757-6769. (10.1039/b907807j)
- Carter, E. and Murphy, D. 2009. Structure-function relationships and mechanistic pathways in homogeneous catalysis as probed by ENDOR spectroscopy. In: Yarwood, J., Douthwaite, R. and Duckett, S. eds. Spectroscopic properties of inorganic and organometallic chemistry., Vol. 40. Specialist periodical report Cambridge: Royal Society of Chemistry, pp. 355-384., (10.1039/b715580h)
2008
- Murphy, D. M.et al. 2008. Discrimination of geometrical epoxide isomers by ENDOR spectroscopy and DFT calculations: the role of hydrogen bonds. Angewandte Chemie. International Edition 47(8), pp. 1414-1416. (10.1002/anie.200703537)
2007
- Carter, E., Carley, A. F. and Murphy, D. M. 2007. Evidence for O2- Radical Stabilization at Surface Oxygen Vacancies on Polycrystalline TiO2. Journal of Physical Chemistry C 111(28), pp. 10630-10638. (10.1021/jp0729516)
- Carter, E., Carley, A. F. and Murphy, D. M. 2007. Free-Radical Pathways in the Decomposition of Ketones over Polycrystalline TiO2: The Role of Organoperoxy Radicals. ChemPhysChem 8(1), pp. 113-123. (10.1002/cphc.200600484)
Teaching
CH0004 Inorganic and Redox Chemistry
CH3307 Advanced Spectroscopy and Siffraction
CHT219 Preparation and Evaluation of Heterogeneous Catalysts
Visible-light Photocatalysis
TiO2 photocatalysis is of fundamental importance in the fields of organic air pollutant remediation, water purification and energy production (in the form of H2). In recent years, several strategies for improving photocatalysis efficiency have been developed, including metal/non-metal doping, dye sensitisation, and mixed-oxide hetero-junctions. Many of these strategies are aimed towards increasing the visible light absorption of TiO2 through reduction of the band gap, altering the valence and conduction band edges, or by increasing the lifetime of the photoexcited electron and hole charge carriers. It is well recognised that these charge carriers can migrate to the surface of the metal oxide, where they participate in redox reactions with surface adsorbed species, generating for example reactive oxygen species (ROS) responsible for organic remediation. Elucidating the mechanistic details of electron transfer processes over well characterised doped metal-oxides is a fundamental requirement for enabling rational design of novel, highly active, photocatalysts - EPR spectroscopy can provide a unique insight to the reaction pathways and intermediates generated under irradiation conditions.
Active Site Structure in Bioinorganic Chemistry
Elucidating the interactions of metal centres within biomolecules have numerous potential benefits, for example in determining enzyme structure and function, advancing the design of metal-based therapeutics and in medical imaging diagnostics. A detailed understanding of these functions and interactions requires the knowledge of molecular structures and conformational dynamics, in particular at the active site of metal coordination. As many of these systems involve paramagnetic centres, they are not readily studied via accessible NMR techniques, whereas EPR spectroscopy is the method of choice to obtain such functional information.
