a
Department of Chemistry, University of Calgary, Calgary, Canada T2N 1N4
E-mail: chivers@ucalgary.ca
;
Fax: +1 403-289-9488
;
Tel: +1 403-220-5741
b
Department of Chemistry, University of St Andrews, St Andrews, UK
c
Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Canada L8S 4M1