Materials. 1-methyl-2-pyrrolidinone (99.5%, Aldrich), 1-octadecene (90%, Aldrich), acetonitrile (99.9%, Fisher Chemical), triphenylbismuth (99%, Strem), CdO (99.5%, Aldrich), diphenyl ether (99%, Aldrich), methanol (ACS grade, VWR), oleic acid (90%, Aldrich), oleylamine (70% Aldrich), selenium (99.99%, Strem), trioctylphosphine (90%, Aldrich), trioctylphosphine oxide (99%, Strem), toluene (ACS grade, VWR). 0.2M Se-ODE was prepared by dissolving selenium powder in 1-octadecene at 200° C. for 2 hr under inert atmosphere according to the procedure by Bullen et al.[42]; trioctylphosphine oxide (TOPO) was recrystallized from acetonitrile prior to use; di-n-octylphosphinic acid (DOPA) was synthesized according to the procedure reported by Wang et al.[1]; a stock suspension of 2 mM triphenylbismuth (BiPh3) in 1-octadecene was prepared in advance.
