* Corresponding authors

^a Department of Chemistry, University of California, One Shields Avenue, Davis, CA, USA
E-mail: whcasey@ucdavis.edu
Fax: +1 530-752-8995
Tel: +1 530-752-3211

^b Department of Geology, University of California, Davis, USA

^c School of Chemistry, Monash University, Melbourne, Victoria, Australia
E-mail: leone.spiccia@sci.monash.edu.au
Fax: +61 3-9905-4597
Tel: +61 3-9905-4526