1 State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510 640, China. jabbatt@chem.utoronto.ca gligorovski@gig.ac.cn.
2 Department of Chemistry, University of Toronto, 80 St. George Street, Toronto M5S 3H6, Canada. jabbatt@chem.utoronto.ca gligorovski@gig.ac.cn.