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                                     Monday 19 SepteMber - Friday 23 SepteMber 2011

The Dr Joan R Clark Scholarships:
Applications are invited for the Dr Joan R Clark Research Scholarships which are supported by the income from gifts by Dr
Joan R Clark, a distinguished mineral crystallographer who was formerly on the staff of the United States Geological Survey.
Dr Clark’s gifts were made in appreciation of her visit to the School of Chemistry as a Fulbright Senior Scholar in chemical
crystallography in 1962. Scholarships are available for PhD candidates whose research topic is mainly in the area of inorganic
chemistry and, in keeping with the donor’s scientific interests, preference shall be given to applicants whose research includes
the determination of inorganic chemical structures by diff raction or other physical techniques. The purpose of the Scholarship is
to assist a postgraduate student proceeding to a Doctorate in the School of Chemistry to undertake research in connection with
his/her doctoral thesis topic at a leading university overseas for a period of not less than six weeks. The value of the scholarship
will be determined on a case-by-case basis, but it is intended that it will be
sufficient to cover the student’s expenses for return travel and subsistence during a continuous residence of between six and
twentysix weeks. As a guide, travel costs up to $3,000 and living expenses up to $500 per week (lower rate for longer visits) have
been granted. In exceptional cases the Scholarship may include an allowance for attendance at a conference before or after the
student’s period of continuous residence.
Applicants must be citizens or permanent residents of Australia. - Closing date:, 5.00pm, Monday 31 October2011

For further information can be obtained for Philip (Phone 9351 4504) . Applications should be sent to Philip and should include a
curriculum vitae, statements explaining the importance of the proposed research in relation to the applicant’s research topic, and
the availability of specialised research resources and/or outstanding research supervision at the overseas institution nominated.
A proposed timetable and costing should be included.
http://www.chem.usyd.edu.au/study/scholarships.html

The Postgraduate Research Support Scheme (PRSS) deadline is on 30 September 2011. PRSS provides support
to enrolled postgraduate research students for a range of expenses and is awarded on a competitive basis. For further
information, guidelines and application instructions, please visit the Chemistry Postgraduate website. http://sydney.edu.au/
science/chemistry/study/pgcurrent3.html#anchor14.



Monday 19 September - LT4, 4.00pm- Monday Afternoon Seminar, Oxidative damage to Biological
Systems: A Theoretical Investigation, Mr Robert J. O’Reilly

Oxidative damage leads to a number of human pathologies, including a number of cancers, arthritis and cardiovascular
disease. The following topics related to oxidative damage are to be discussed:
• N-Chlorinated and N-brominated species induce oxidative damage through the formation of nitrogen-centered radicals arising
via N–X bond cleavage. The effect of substituents on the strength of N–X (X = H, F, Cl and Br) bonds toward homolysis will be
discussed [1–3].

• Hydrogen-atom abstraction reactions from the a-C–H moieties of amino acids provides the impetus for the fragmentation
of such species. On the other hand, experiments show that the a-C–H positions are inherently inert toward hydrogen-atom
abstraction reactions by electrophilic radicals. The reactions of Cl• with amino acids and their derivatives will be discussed [4].

• Isothiocyanates are a class of molecules with potent anticancer activities. They may be generated synthetically by way of the
fragmentation reactions of 1,4,2-oxathiazoles. The thermodynamics and kinetics associated with the fragmentation reactions of
a number of such heterocycles will be discussed [5].

References
[1] O’Reilly, R. J.; Karton, A.; Radom, L. J. Phys. Chem. A 2011, 115, 5496–5504.
[2] Pattison, D. I.; O’Reilly, R. J.; Skaff, O.; Radom, L.; Anderson, R. F.; Davies, M. J. Chem. Res. Toxicol. 2011, 24, 371–382.
[3] O’Reilly, R. J.; Karton, A.; Radom, L. Int. J. Quantum Chem. 2011, DOI:10.1002/qua.23210
[4] O’Reilly, R. J.; Chan, B.; Taylor, M. S.; Ivanic, S.; Bacskay, G. B.; Easton, C. J.; Radom, L. J. Am.
[3] O’Reilly, R. J.; Karton, A.; Radom, L. Int. J. Quantum Chem. 2011, DOI:10.1002/qua.23210
[4] O’Reilly, R. J.; Chan, B.; Taylor, M. S.; Ivanic, S.; Bacskay, G. B.; Easton, C. J.; Radom, L. J. Am. Chem. Soc. 2011, In Press.
[5] O’Reilly, R. J.; Radom, L. Org. Lett. 2009, 11, 1325–1328.

Refreshements will follow this lecture

Friday 21 September, LT2, 9.00am, Wednesday Morning Seminar, Spin crossover complexes and [M3Ln]
macrocyclic single-molecule magnets, Professor Sally Brooker

Humphrey L.C. Feltham,1 Matthew G. Cowan,1 Jonathan A. Kitchen,1 Nicholas G. White,1 Juan Olguin,1 Guy N. L. Jameson,1 Jeffery
L. Tallon,2 Claudio Gandolfi,3 Martin Albrecht,3 Rodolphe Clerac,4 Annie K. Powell5 and Sally Brooker1,*
1
  Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, PO Box 56,
  Dunedin 9054, New Zealand
2
  MacDiarmid Institute for Advanced Materials and Nanotechnology and Industrial Research Limited, Lower Hutt, New Zealand
3
  School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
4
  CNRS, UPR 8641, Centre de Recherche Paul Pascal (CRPP), Equipe “Matériaux Moléculaires Magnétiques”, Pessac, France.
5
  Institut für Anorganische Chemie, Karlsruher Institut für Technologie, Karlsruhe, Germany

Our interests in spin crossover (SCO) started when we identified that a dicobalt complex of a [2+2] Schiff-base macrocycle based
on 3,6-diformylpyridazine, L, [CoII2L(NCS)2(SCN)2], had unique SCO behaviour. Our focus in the area of SCO then moved on to the
formation of related triazole-based complexes of iron(II). The first iron complex we prepared, [FeII2(PMAT)2](BF4)4•DMF, utilised a
bis-terdentate triazole ligand, PMAT, and led to the first structural characterization of a mixed spin state dimetallic complex.




Figure: left [Co2L(NCS)2(SCN)2]; middle [Fe2(PMAT)2](BF4)4•DMF; right [Zn3Dy(LPr)(NO3)3(MeOH)3].

More recently we have also started exploring the controlled preparation of Single-Molecule Magnets (SMMs). Inspired by the [3+3]
macrocycles described by Nabeshima and MacLachlan, we have prepared M3Ln SMMs using Schiff-base macrocycles such as
(LPr)6- with approximate 3-fold symmetry.

This lecture will describe our recent results in the SCO and SMM fields. It will focus on self-assembling systems featuring transition
metal complexes of (a) related triazole-based ligands, (b) new pyrazine-based ligands and (c) a new class of macrocyclic SMMs.

Acknowledgment:
We thank the Marsden Fund (RSNZ), MacDiarmid Institute for Advanced Materials and Nanotechnology and the University of Otago
for supporting this research

Host: Dr Deanna D’Alessandro - Room 457

Wednesday 21 September 2011, LT2, 5.30pm The 666th meeting of the Sydney University Chemical
Society, Strategies for antibacterial biomaterials surfaces, Professor Hans J. Griesser

Bacterial attachment and subsequent biofilm formation might be reduced by application of a thin coating that deters bacterial
colonisation.1,2 For biomedical devices a coating should also allow good attachment of human tissue to facilitate wound healing, or
for catheters and contact lenses be lubricious and not bio-adhesive. As requirements differ for antibacterial coatings for different
implants and devices, we are studying several approaches for fabricating antibacterial coatings.3 For long-lasting effect, we prefer
the approach of covalently immobilising antibacterial molecules; we have also investigated the alternative approach of release of
silver ions.4

Our strategies are based on plasma polymer thin film coatings, because this approach can be transferred to coat many polymeric,
metallic and ceramic materials. Plasma polymers with chemically reactive surface groups enable covalent immobilisation of
antibacterial compounds onto their surface. Alternatively, we load plasma polymer coatings with silver nanoparticles, from which
Ag+ ions can outdiffuse.4 Organic antibacterial compounds investigated were the commercially available antibiotic novobiocin5 and
serrulatanes,5 the latter are novel substituted diterpenes extracted from Australian plants used in traditional medicine.6 The chemical
composition of coatings was assessed by XPS and ToF-SIMS to ensure that the intended coatings were achieved.
Samples were tested for bacterial attachment and for biofilm formation, as well as for mouse 3T3 fibroblast cell attachment. Covalently
grafted poly(ethylene glycol) (PEG) coatings were used as non-adhesive control surfaces. Serrulatanes were also tested in solution
for bacterial inhibition and fibroblast cytotoxicity.

Surface-immobilised PEG, novobiocin, and serrulatanes reduced bacterial attachment by up to 99.8%. While large biofilm communities
formed on control surfaces within 48 hrs, these coatings prevented biofilm formation. Plasma polymer coatings loaded with Ag
nanoparticles also were effective; Ag+ delivery can be adjusted via the properties and thickness of the plasma polymer film and the
silver loading 4 Testing of coatings with m3T3 fibroblast cell cultures showed, however, that in many cases there were adverse effects.
Silver in particular affected 3T3 cells. With organic antibiotics, the surface density appears important and an optimum must be found
between deleterious cell effects and antibacterial effectiveness.5

Important questions remain: do surface-immobilised antibiotics act as in solution ? Do in vitro and in vivo tests correlate? How to
mitigate adverse effects on mammalian cells?

References:
1. H.J. Griesser, K. Vasilev, H. Ys and S.A. Al-Bataineh, Antibacterial Surfaces and Coatings. in: Surface Modification of Biomaterials;
R. Williams (Ed.), Woodhead Publishing, Cambridge, UK, 2011; 2. K. Vasilev, J. Cook and H.J. Griesser, Antibacterial Surfaces for
Biomedical Devices. Expert Review of Medical Devices, 6, 553-567 (2009); 3. H.J. Griesser, H. Ys, C.P. Ndi, L. Britcher, K. Vasilev,
M. Jasieniak, S.S. Griesser, S.J. Semple, Combating Infections at Biomedical Implants and Devices by Antibacterial Coatings.
Chemistry in Australia, 75 (10), 5-8, 2008; 4. K. Vasilev, V. Sah, K. Anselme, C. Ndi, M. Mateescu, B. Dollmann, P. Martinek, H. Ys,
L. Ploux, H.J. Griesser, Tunable antibacterial coatings that support mammalian cell growth. NanoLetters, 10, 202-207 (2010); 5. H.
Ys, Antibacterial Coatings for Biomedical Devices by Covalent Grafting of Serrulatane Diterpenes. PhD Thesis, University of South
Australia, 2010; 6. C.P. Ndi, S.J. Semple, H.J. Griesser, S.M. Pyke, M.D. Barton, Antimicrobial compounds from Eremophila serrulata.
Phytochemistry, 68, 2684-2690 (2007).

Refreshments from 5pm

Friday 23 September, 11.00am, LT4 - Friday Morning Seminar, Towards Catalytic Alkane Oxidation via O2 Insertion into Platinum
Methyl Bonds, Professor George Britovsek

The selective oxidation of methane to methanol, catalysed by electrophilic late transition metals such as platinum, has attracted
much interest since the first observations by Shilov and Gol’dshleger in the late 1960s. The mechanism of the overall reaction (Eq.
1), as proposed by Shilov,1 consists of three steps: 1) C-H activation at a Pt(II) centre generating a Pt-Me bond, 2) oxidation of the
Pt(II) centre to Pt(IV) and 3) functionalisation of the methyl group via reductive elimination of methanol and regeneration of the Pt(II)
complex.2
 CH4 + H2O         + [PtCl6]2-                    CH3OH + 2 H+ + 2 Cl– + [PtCl4]2-                     (1)
In the original Shilov reaction, the second step was carried out by a stoichiometric Pt(IV) oxidant. As part of our studies on alternative
oxidants for the Shilov reaction, we have previously reported some of our work on H2O2 oxidations.3 More recently, we have used
O2 as the oxidant and we have discovered an O2 insertion into a platinum(II) methyl bond to give a methyl peroxo complex (Eq. 2).4


 LnPt-CH3 + O2                         LnPt-O-O-CH3               (2)
The methyl peroxo platinum(II) complex eliminates formaldehyde to form a hydroxo platinum(II) complex. These novel reactions
suggest the possibility for the selective oxidation of alkanes to aldehydes, as shown in the catalytic cycle below. Currently, we are
investigating the C-H activation of alkanes with metal hydroxo complexes, a reaction for which several examples have recently been
reported. Catalytic results and mechanistic implications will be discussed.




References:
1. L. A. Kushch, V. V. Lavrushko, Y. S. Misharin, A. P. Moravsky, A. E. Shilov, Nouv. J. Chim., 1983, 7, 729.
2. S. S. Stahl, J. A. Labinger, J. E. Bercaw, Angew. Chem. Int. Ed., 1998, 37, 2180.
3. R.A. Taylor, D.J. Law, G.J. Sunley, A.J.P. White, G.J.P. Britovsek, Chem. Commun. 2008, 2800.
4. R.A. Taylor, D.J. Law, G.J. Sunley, A.J.P. White, G.J.P. Britovsek, Angew. Chem. Int. Ed. 2009, 48, 5900.

Host: A/Professor Anthony Masters - Room 459

				
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