S. Fujimaki et al., APPLICATION OF ELECTROSPRAY-IONIZATION TO THE OBSERVATION OF HIGHER FULLERENE ANIONS, Rapid communications in mass spectrometry, 7(12), 1993, pp. 1077-1081
Negative-ion electrospray mass spectrometry for the detection of highe
r fullerene anions is discussed. The fullerenes were reduced in dimeth
oxyethane/aromatic solvent using NaK amalgam and analyzed by electrosp
ray ionization mass spectrometry using a double-focusing mass spectrom
eter. All the C(n)- ions (n = 2k, and k is an integer) could be detect
ed up to n = 102 except for 60 < n < 70 and n = 72. The detection effi
ciency Of C76 is found to be considerably lower than that for C78, pro
bably because the C76- ion reacts further in solution and is converted
to undetectable reaction products. In addition to the fullerene anion
s, large peaks due to methoxy-substituted fullerene anions, C(n)(OCH3)
m-, are observed. The intensities of these ions grow with time.