Prof. Paul J. Low
(email at email@example.com)
Paul was born and raised in Elizabeth, South Australia, which is conveniently half-way point between the state capital of Adelaide and the Barossa Valley. He graduated from the University of Adelaide with his B.Sc (Double Major in Chemistry (1992, David Murray Scholarship in Science, G.M. Badger Prize) and B.Sc(Hons) (1993, Rennie Scholarship). He completed his PhD with Michael I. Bruce in 1997 having studied the synthesis and reactions of metal complexes bearing carbon-rich ligands. Paul subsequently moved to Canada to take up a Canadian Government Laboratories Visiting Fellowship at the NRC Steacie Institute for Molecular Sciences with Arthur J. Carty, before moving to Durham to take up a Lectureship in Inorganic Chemistry in 1999. He was promoted to Reader in 2006 and to a Chair in 2010. Paul is a Fellow of the Royal Australian Chemical Institute (2008), and currently holds and EPSRC Leadership Fellowship.
The Low group at Durham promotes a multidisciplinary approach to the determination of electronic structure in molecular compounds. We run a research program of considerable breadth and collaborative effort in which spectroscopic tools are chosen and matched with chemical synthesis, molecular structure determination, computational chemistry and surface science to provide insight into the physical properties of organometallic (particularly carbon-rich) systems, and organic molecular materials.
The group has active interests in the synthesis and reactions of complexes bearing the butatrienylidene C=C=C=CH2, diynyl (C≡CC≡CR), diyndiyl (C≡CC≡C) and related ligands including cyanoacetylide (C≡CC≡N) and cyanovinylidene (C=C(CN)2), together with the use of spectroelectrochemical methods to study these systems. In particular, the use of IR spectroelectrochemistry and ν(C≡C) data from complexes across a series of oxidation states can be used to aid to the interpretation of the electronic structures and character of electronic transitions in bimetallic complexes of general form [LxM-(C≡CRC≡C)-MLx]+ in terms of redox non-innocent bridging ligand character rather than metal-localised mixed-valencey. These studies are immensely important given the vast body of recent literature in which metal-based mixed-valency has been assumed as a prelude to interpretations of NIR spectroscopic data and discussions of bridge-mediated electron transfer.
An area of particular interest for the group at present is the extension of the ideas of 'two-site' mixed valencey to sytems in which electron exchange and charge transfer can take place over more complicated intramolecular pathways
- N.J. Brown, H.N. Lancashire, M.A. Fox, D. Collison, R. Edge, D.S. Yufit, J.A.K. Howard, M.W. Whiteley, P.J. Low, Molybdenum complexes of C,C-bis(ethynyl)carborances: the design, synthesis and study of a weakly coupled mixed-valence compound, Organometallics, 2011, accepted in press (DOI 10.1021/om1010353).
- F. Malvolti, P. Le Maux, L. Toupet, M.E. Smith, W.Y. Man, P.J. Low, E. Galardon, G. Simonneaux, F. Paul, Self-assembled molecular wires from organoiron metallo-ligands and ruthenium tetramesityl porphyrin, Inorg. Chem., 2010, 49, 9101 - 9103.
- M.A. Fox, J.D. Farmer, R.L. Roberts, M.G. Humphrey, P.J. Low, Non-innocent ligand behavior in diruthenium complexes containing a 1,3-diethynylbenzene bridge, Organometallics, 2009, 28, 5266-5269.
- M.E. Smith, E.L. Flynn, M.A. Fox, A. Trottier, E. Wrede, D.S. Yufit, J.A.K. Howard, K.L. Ronayne, M. Towrie, A.W. Parker, F. Hartl, P.J. Low, Facile photogeneration of a charge separated state in a cyanoacetylide bridged Fe(II)-Re(I) heterobimetallic complex, Chem. Commun., 2008, 5845-5847.
- D.J. Armitt, M.I. Bruce, M. Gaudio, N.N. Zaitseva, B.W. Skelton, A.H. White, B. Le Guennic, J.F. Halet, M.A. Fox, R.L. Roberts, F. Hartl, P.J. Low, Some transition metal complexes derived from mono- and di-ethynyl perfluorobenzenes, Dalton Trans., 2008, 6763-6775.
- M.A. Fox, B. Le Guennic, R.L. Roberts, T.E. Baines, D.S. Yufit, D. Albesa-Jové, J.F. Halet, F. Hartl, J.A.K. Howard, P.J. Low, Ruthenium complexes of diethynyl carboranes: An investigation of electronic interactions mediated by a spherical pseudo-aromatic spacer, J. Am. Chem. Soc., 2008, 130, 3566-3578.
Conjugated Organic Molecules
We are actively pursuing the chemistry of carbon-rich organic molecules, particularly those derived from 1,4-bis(phenylethynyl)benzene (BPEB) in collaboration with Beeby and Wrede (Durham), Cea (Zaragoza) and Nichols (Liverpool). Studies of the emissive behaviour of BPEB have shown the anomalous emission behaviour of this prototypical conjugated system arising from restricted rotation in viscous media, whilst cavity ring-down spectroscopy has been used to measure the barrier to rotation of the aromatic ring systems around the long molecular axis. These fundamental studies directly impact upon designs of molecular wires, switches and gyroscopes. In collaboration with Cea (Zaragoza) and Nichols (Liverpool) and their respective colleagues, we explore the conductivity of metal | BPEB | metal junctions constructed from both single molecules (single molecule conductance, SMC) and large area Langmuir-Blodgett (LB) films to demonstrate the effects of lateral p-interactions (or near neighbour eff ects) on single molecule conduction, and also to explore the efficacy of surface binding groups such as amines and trialkylsilyls that provide alternatives to the well-established, but mobile, thiol-gold contact. Studies of the intermolecular interactions in BPEB derivatives have also given rise to an embryonic interest in liquid crystal systems (with Prof John Seddon, Imperial).
- G. Pera, S. Martin, L.M. Ballesteros, A.J. Hope, P.J. Low, R.J. Nichols, P. Cea, Metal-molecule-metal junctions in Langmuir-Blodgett (LB) films using a new linker: trimethylsilane, Chem. Eur. J., 2010, 16, 13398 - 13405
- Villares, G. Pera, S. Martin, R. Nichols, D.P. Lydon, L. Applegarth, A. Beeby, P.J. Low, P. Cea, Fabrication, characterization and electrical properties of Langmuir-Blodgett films of an acid terminated phenylene-ethynylene oligomer, Chem. Mater., 2010, 22, 2041 - 2049.
- Villares, D.P. Lydon, P.J. Low, B.J. Robinson, G.J. Ashwell, F.M. Royo, P. Cea, Langmuir-Blodgett film construction, characterization and molecular conductivity of an amine-terminated oligo(phenylene ethynylene), Chem. Mater., 2008, 20, 258-264.
- Villares, S. Martin, I. Giner, D.P. Lydon, P.J. Low, P. Cea, The use of scanning polarization force microscopy to study the miscibility of a molecular wire candidate and an insulating fatty acid in mixed LB films, Soft Matter, 2008, 4, 1508-1514
- D.P. Lydon, D. Albesa-Jové, G.C. Shearman, J.M. Seddon, J.A.K. Howard, T.B. Marder, P.J. Low, The synthesis and liquid crystalline behaviour of alkoxy substituted derivatives of 1,4-bis(phenylethynyl)benzene, Liq. Cryst., 2008, 35, 119-132.
- S.J. Greaves, E.L. Flynn, E.L. Futcher, E. Wrede, D.P. Lydon, P.J. Low, S.R. Rutter, A. Beeby, Cavity ring-down spectroscopy of the torsional motions of 1,4-bis(phenylethynyl)benzene, J. Phys. Chem. A, 2006, 110, 2114-2121
Hole Transport Materials
Triaryl amines offer a well-behaved one-electron redox couple, which when coupled with their tendency to form molecular glasses makes them attractive hole-transport materials. The hole transport process in these materials can be described in terms of series of intermolecular electron transfer reactions, and consequently there is interest in establishing the structures of aryl amines in the electrochemically accessible redox states, and ganering information about the associated structural re-organisation barriers to the charge transport process. We have used a combination of spectroelectrochemical methods, including including resonance Raman which provides a method for the detection of these charged species in operating devices.
- P.J. Low, M.A.J. Paterson, D.S. Yufit, J.A.K. Howard, J.C. Cherryman, D.R. Tackley, R. Brook, B. Brown, Towards an understanding of structure property relationships in hole-transport materials: The influence of molecular conformation on oxidation potential in poly(aryl)amines, J. Mater. Chem., 2005, 15, 2304-2315
- R.E. Littleford, M.A.J. Paterson, P.J. Low, D.R. Tackley, L. Jayes, G. Dent, J.C. Cherryman, W.E. Smith, In-situ generation and analysis of charge transfer materials using Raman spectroelectrochemistry, Phys. Chem., Chem. Phys., 2004, 6, 3257 - 3263
- P.J. Low, M.A.J. Paterson, A.E. Goeta, D.S. Yufit, J.A.K. Howard, J.C. Cherryman, D.R. Tackley, B. Brown, The molecular structures and electrochemical response of "twisted" tetra(aryl) benzidenes, J. Mater. Chem., 2004, 14, 2516 - 2523
- P.J. Low, M.A.J. Paterson, H. Puschmann, A.E. Goeta, J.A.K. Howard, C. Lambert, J.C. Cherryman, D.R. Tackley, S. Leeming, B. Brown, The crystal, molecular and electronic structure of N,N'-diphenyl, N,N'-bis(2,4-dimethylphenyl)-(1,1'-biphenyl)-4,4'diamine and the corresponding radical cation, Chem. Eur. J., 2004, 10, 83-91
Recent Reviews and Perspectives
- S.J. Higgins, R.J. Nichols, S. Martin, P. Cea, H.S.J. va der Zant, M.M. Richter, P.J. Low, Looking ahead: challenges and opportunities in organometallic chemistry, Organometallics, 2011, 30, 7 - 12.
- R. Buschbeck, P.J. Low, H. Lang, Homoleptic transition metal acetylides, Coord. Chem. Rev., 2011, 255, 241.
- P.J. Low, N.J. Brown, Electronic interactions between and through covalently bonded polymetallic complexes, J. Cluster Sci., 2010, 21, 235 - 278
- P.J. Low, Metal complexes in molecular electronics: Progress and possibilities, Dalton Trans., 2005, 2821-2824
Full Publication List: http://www.researcherid.com/rid/A-4014-2011
Dr Horst Puschmann is gratefully acknowledged for the provision of some of the graphics on this page.
- Organometallic Chemistry
- Molecular Electronics
- Redox Chemistry
- A.S. Batsanov, P.J. Low & M.A.J. Paterson (2006). 4,4 '-Diamino-2,2 ',6,6 '-tetramethylbiphenyl. 62: O2973-O2975.
- S.J. Greaves, E.L. Flynn, E.L. Futcher, E. Wrede, D.P. Lydon, P.J. Low, S.R. Rutter & A. Beeby (2006). Cavity ring-down spectroscopy of the torsional motions of 1,4-bis(phenylethynyl)benzene. 110(6): 2114-2121.
- M.A. Fox, T.E. Baines, D. Albesa-Jove, J.A.K. Howard & P.J. Low (2006). Improved syntheses of bis(ethynyl)-para-carboranes, 1,12-(RC C)(2)-1,12-C2B10H10 and 1,10-(RC equivalent to C)(2)-1,10-C2B8H8 (R = H or Me3Si). 691(18): 3889-3894.
- W.M. Khairul, L. Porres, D. Albesa-Jove, M.S. Senn, M. Jones, D.P. Lydon, J.A.K. Howard, A. Beeby, T.B. Marder & P.J. Low (2006). Metal cluster terminated "molecular wires". 17(1): 65-85.
- M.I. Bruce, N.N. Zaitseva, P.J. Low, B.W. Skelton & A.H. White (2006). Polymetallation of alkenes: Formation of some complexes containing branched chain carbon-rich ligands. 691(20): 4273-4280.
- X.J. Zhu, R.M. Ward, D. Albesa-Jove, J.A.K. Howard, L. Porres, A. Beeby, P.J. Low, W.K. Wong & T.B. Marder (2006). Synthesis of new mer,trans-rhodium(III) hydrido-bis(acetylide) complexes: Structure of mer,trans- (PMe3)(3)Rh(C equivalent to C-C6H4-4-NMe2)(2)H. 359(9): 2859-2863.
- M.A. Fox, A.M. Cameron, P.J. Low, M.A.J. Paterson, A.S. Batsanov, A.E. Goeta, D.W.H. Rankin, H.E. Robertson & J.T. Schirlin (2006). Synthetic and structural studies on C-ethynyl- and C-bromo-carboranes. (29): 3544-3560.
- M.E. Smith, R.L. Cordiner, D. Albesa-Jove, D.S. Yufit, F. Hartl, J.A.K. Howard & P.J. Low (2006). The synthesis, structure, and electrochemical properties of Fe(C CC N)(dppe)Cp and related compounds. 84(2): 154-163.
- R.L. Cordiner, M.E. Smith, A.S. Batsanov, D. Albesa-Jove, F. Hartl, J.A.K. Howard & P.J. Low (2006). The synthesis, structure, reactivity and electrochemical properties of ruthenium complexes featuring cyanoacetylide ligands. 359(3): 946-961.
- R.L. Cordiner, M.P. Feroze, C. Lledo-Fernandez, D. Albesa-Jove, J.A.K. Howard & P.J. Low (2006). Trimetallic complexes featuring Group 10 tetracyanometallate dianions as bridging ligands. 359(11): 3459-3466.
Journal papers: academic
- Ballesteros, LM, Martin, S, Momlona, C, Marques-Gonzalez, S, Lopez, MC, Nichols, RJ, Low, PJ & Cea, P (2012). Acetylene Used as a New Linker for Molecular Junctions in Phenylene-Ethynylene Oligomer Langmuir-Blodgett Films. The Journal of Physical Chemistry C 116(16): 1932-7447 (print), 1932-7455 (electronic).