* Corresponding authors

^a James Cook University, Townsville, Australia
E-mail: ian.atkinson@jcu.edu.au
Fax: +61 7 4781 5230
Tel: +61 7 4781 4551

^b Sydney Grammar School, College Street, Sydney 2010, Australia
E-mail: mmb@sydgram.nsw.edu.au
Fax: +61 2 9331 5164
Tel: +61 2 9332 5820

^c The Centre for Heavy Metal Research, School of Chemistry, University of Sydney, Sydney 2006, Australia
E-mail: Lindoy@chem.usyd.edu.au
Fax: +61 2 9351 3329
Tel: +61 2 9351 4400