Dr. Clayden studied for his B.A. in Chemistry at St Catherines College, Oxford University. Dr. Clayden's D. Phil., also from Oxford University, was concerned with shielding effects in NMR spectra and their use in conformational analysis. After a post-doctoral stint at MIT with Professor Waugh Dr. Clayden returned to Oxford University as a Shell Research Fellow. In 1986 Dr. Clayden joined ICI at the Wilton Research Centre where he managed a solid state NMR and materials NMR imaging. Dr. Clayden moved to UEA in 1994 where he is a member of the Molecular Structure Centre.

Nigel’s main interests lie in three areas. First, the characterisation of inorganic materials by solid state NMR methods. Thus, C-13 CPMAS demonstrates that halo alkyl phosphonates will react to incorporate imidazole and can be used in supported zirconium phosphonate catalysts. Second, the determination of protein dynamics through solution state NMR N-15 relaxation parameters. In the case of the in the E9 colicin system analysis of the relaxation data in the translocation domain has indicated local ordering around the TolB box. Third, the application of radio-frequency methods in µSR. In a recent experiment muon depolarisation of the FMuF state in SrF2 was studied using spin-locked muon polarisation and matched radiofrequency fields in the rotating frame.

Inorganic Materials

Phosphosilcate gels, P2O5 – xSiO2, used as sensors Functionalised zirconium phosphonate supported catalysts Muon spin relaxation studies of proton conductors

Protein dynamics Inorganic Materials

Multinuclear solid state NMR spectroscopy both static and MAS are being used to investigate the structure and dynamics in a range of inorganic materials. 1. Phosphosilcate gels, P2O5 – xSiO2, used as sensors

Solid state 1H, 29Si and 31P MAS NMR have been used to investigate the microstructure of phosphosilicate gels prepared by a new procedure. Molar compositions of 5, 10, 20 and 30 mol% P2O5 in P2O5 -SiO2 were studied. After drying to 400oC the dried gels have very similar structures formed by a siloxane framework containing cross-linked phosphorus. Upon exposure to moisture, as in a functioning device, hydrolysis of the Si-O-P bonds takes place and and effectively trapped molecules of orthophosphoric acid are formed. Unlike earlier samples, the residual co-polymerisation of phosphate and silicate tetrahedral was much reduced and although it increased with phosphorus content, it still represented less than 70% of the phosphorus. Furthermore there was no evidence for six-coordinated silicon in the glassy matrix 2. Functionalised zirconium phosphonate supported catalysts

This project, in collaboration with Professor M Bochmann, involves the synthesis and evaluation of functionalised zirconium phosphonates (ZrPs) and their use as a new family of generic catalyst supports. ZrP materials are unique in possessing well-defined crystalline surfaces coated with organic substituents which allow the precise tailoring of the surface chemistry. Based on preliminary results with ZrP-supported olefin polymerisation catalysts, the method will be used to design a range of novel ZrP-supported lanthanide and transition metal catalysts for a range of applications, including polymerisations, Lewis-acid catalysed transformations and in particular esterification and polymerisation catalysts. 3. Muon spin relaxation studies of proton conductors

Muons are being used as extrinsic probes of the proton/muonium dynamics in proton conductors to complement 1H NMR. Zero field muon spin relaxation is dominated by the local nuclear dipolar field which is then averaged by dynamics processes with increasing temperature. In the case of HZr2(PO4)3.xH2O HMuO is formed which undergoes a fast local motion around 160 K, in contrast HMuO is static in Zr(H2PO4)(PO4).2H2O up to 320 K. One question arising from this work are the factors which determine whether addition or substitution occurs: that is addition to H2MuO+ or substitution to HMuO. Radiofrequency methods in muon spin relaxation are also being developed. At its simplest cw irradiation of the nuclear spin will decouple the muon and nuclear spin dipolar fields leading to a marked reduction in the zero field relaxation rate. More sophisticated experiments involving polarisation transfer between the muon and a nuclear spin are being explored using the FMuF state found in CaF2. Protein dynamics

N relaxation rates R1, R2 and the NH heteronuclear nOe are being used to study the backbone dynamics of proteins in the E9 colicin system, with the recent emphasis on the disordered translocation domain. Data analysis is carried out using in-house Windows based computer programs: R2R1Win, rotational diffusion anisotropy from the R2/R1 ratio, LSWin, Lipari-Szabo model free approach, LocalWin, for Lipari-Szabo analysis in which the global rotational diffusion is taken as a local variable and RSAWin for reduced spectral density analysis. Moment of inertia calculations are carried out using moment. Proteins studied include: Im9, DNase domain, apo and metal bound, R domain, intact colicin and a fusion protein of the terminal 61 residues of the translocation domain and the DNase domain.

Jayasooriya, U., Clayden, N., Steytler, D., Peck, J., Oganesyan, V., Khasanov, R., Scheuermann, R., Stoykov, A.(2016)Rate of Molecular Transfer of Allyl Alcohol across an AOT Surfactant Layer Using Muon Spin Spectroscopyin Langmuir32.pp. 664-672 Full Text UEA Repository(Article) Whittaker, S., Clayden, N., Moore, G.(2011)NMR characterisation of the relationship between frustration and the excited state of Im7.in Journal of Molecular Biology414.pp. 511-29 Full Text UEA Repository(Article) Qi, S., Belton, P., Nollenberger, K., Clayden, N., Reading, M., Craig, D.(2010)Characterisation and Prediction of Phase Separation in Hot-Melt Extruded Solid Dispersions: A Thermal, Microscopic and NMR Relaxometry Studyin Pharmaceutical Research27.pp. 1869-1883 Full Text UEA Repository(Article) Chessa, S., Clayden, N., Bochmann, M., Wright, J.(2009)α-Zirconium phosphonates: versatile supports for N-heterocyclic carbenesin Chemical Communicationspp. 797-799 Full Text UEA Repository(Article) Clayden, N. J., Cottrell, S. P.(2006)Muon spin relaxation study of Zr(H2PO4)(PO4)center dot 2H(2)Oin Physical Chemistry Chemical Physics8.pp. 3094-3098 Full Text UEA Repository(Article) Clayden, N., Esposito, S., Ferone, C., Pansini, M.(2006)Substitution clustering in a non-stoichiometric celsian synthesized by the thermal transformation of barium exchanged zeolite Xin Journal of Solid State Chemistry179.pp. 1957-1964 Full Text UEA Repository(Article) Aronne, A., Turco, M., Bagnasco, G., Pernice, P., Di Serio, M., Clayden, N. J., Marenna, E., Fanelli, E.(2005)Synthesis of high surface area phosphosilicate glasses by a modified sol-gel methodin Chemistry of Materials17.pp. 2081-2090 Full Text UEA Repository(Article) Clayden, N. J., Pernice, P., Aronne, A.(2005)Multinuclear NMR study of phosphosilicate gels derived from POCl3 and Si(OC2H5)(4)in Journal of Non-Crystalline Solids351.pp. 195-202 Full Text UEA Repository(Article) Tozawa, K., Macdonald, C. J., Penfold, C. N., James, R., Kleanthous, C., Clayden, N. J., Moore, G. R.(2005)Clusters in an intrinsically disordered protein create a protein-binding site: The TolB-binding region of colicin E9in Biochemistry44.pp. 11496-11507 Full Text UEA Repository(Article) Clayden, N. J., Aronne, A., Esposito, S., Pernice, P.(2004)Solid state NMR study of phosphosilicate gelsin Journal of Non-Crystalline Solids345.pp. 601-604 Full Text UEA Repository(Article) Clayden, N. J., Jayasooriya, U. A., Cottrell, S. P.(2004)Muon spin relaxation study of the proton conductor HZr2(PO4)(3)in Solid State Ionics170.pp. 51-55 Full Text UEA Repository(Article) Macdonald, C. J., Tozawa, K., Collins, E. S., Penfold, C. N., James, R., Kleanthous, C., Clayden, N. J., Moore, G. R.(2004)Characterisation of a mobile protein-binding epitope in the translocation domain of colicin E9in Journal of Biomolecular NMR30.pp. 81-96 UEA Repository(Article) Anson, C. E., Baldwin, T. J., Clayden, N. J., Creaser, C. S., Egyed, O., Fey, M. A., Hutchinson, W. E., Kavanagh, A., Stephenson, G. R., Walker, P. I.(2003)Silica-mounted FTIR-active organometalcarbonyl derivatives as functional materialsin Journal of Optoelectronics and Advanced Materials5.pp. 533-554 UEA Repository(Article) Boetzel, R., Collins, E. S., Clayden, N. J., Kleanthous, C., James, R., Moore, G. R.(2003)Structural dynamics of the receptor-binding domain of colicin E9in Faraday Discussions122.pp. 145-162 Full Text UEA Repository(Article) Clayden, N. J., Esposito, S., Ferone, C., Pansini, M.(2003)Si-29 and Al-27 NMR study of the thermal transformation of barium exchanged zeolite-A to celsianin Journal of Materials Chemistry13.pp. 1681-1685 Full Text UEA Repository(Article) Clayden, N. J., Esposito, S., Pernice, P., Aronne, A.(2002)Solid state H-1 NMR study, humidity sensitivity and protonic conduction of gel derived phosphosilicate glassesin Journal of Materials Chemistry12.pp. 3746-3753 Full Text UEA Repository(Article) Collins, E., Whittaker, S., Tozawa, K., Macdonald, C., Boetzel, R., Penfold, C., Reilly, A., Clayden, N., Osborne, M., Hemmings, A., Kleanthous, C., James, R., Moore, G.(2002)Structural dynamics of the membrane translocation domain of colicin E9 and its interaction with TolB.in Journal of Molecular Biology318.pp. 787-804 Full Text UEA Repository(Article) Clayden, N. J., Esposito, S., Aronne, A.(2001)Chemical heterogeneity in phosphosilicate gels by NMR magnetisation exchangein Journal of the Chemical Society-Dalton Transactionspp. 2003-2008 UEA Repository(Article) Clayden, N. J., Esposito, S., Pernice, P., Aronne, A.(2001)Solid state Si-29 and P-31 NMR study of gel derived phosphosilicate glassesin Journal of Materials Chemistry11.pp. 936-943 UEA Repository(Article) Clayden, N. J., Pendlebury, R.(2001)NMR study of the effect of electron beam processing on a poly(ether-block-amide)in Polymer42.pp. 8373-8377 UEA Repository(Article)