Preparative-scale liquid chromatography and characterization of large fullerenes generated in low-pressure benzene flames
- Massachusetts Inst. of Technology, Cambridge, MA (United States)
Soot generated in a premixed benzene/oxygen/argon low-pressure flame was extracted sequentially with dichloromethane, toluene, CS{sub 2} and 1,2-dichlorobenzene. Quantifications by HPLC were performed for C{sub 60}, C{sub 70}, C{sub 76}, C{sub 78}, and C{sub 84} by means of external standards using a monomeric octadecylsilica (ODS) bonded stationary phase and acetonitrile/toluene (55:45) as a mobile phase. Toluene was found to be the most suitable solvent for all the cases studied here. After the partial removal of smaller fullerenes with preparative HPLC, the presence of fullerenes up to C{sub 104} was shown by means HPLC-APCI-MS using a heated nebulizer interface. The macroscopic isolation of C{sub 86}, C{sub 90}, C{sub 92}, C{sub 94} and C{sub 96} was performed using a two-step HPLC separation with a 2-(1-pyrenyl)ethylsilica stationary phase and toluene as eluent preceded by the partial removal of C{sub 60} and C{sub 70} with a poly(divinylbenzene) HPLC column. UV-vis spectra were measured, and the presence of a C{sub 90} adduct could be discerned. Based on the results of this work, the estimated ratios C{sub 60}:C{sub 70}:C{sub 76}: C{sub 78}:C{sub 84} in the investigated flame-generated soot are 100:100:4:3:6 while the corresponding values for C{sub 84}:C{sub 86}:C{sub 90}: C{sub 92}:C{sub 94}:C{sub 96} are 100:0.5:5:0.5:1.25:1. 45 refs., 9 figs., 4 tabs.
- DOE Contract Number:
- FG02-84ER13282
- OSTI ID:
- 437745
- Journal Information:
- Journal of Physical Chemistry, Vol. 100, Issue 50; Other Information: PBD: 12 Dec 1996
- Country of Publication:
- United States
- Language:
- English
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