Putting ammonia into a chemically opened fullerene.
We put ammonia into an open-cage fullerene with a 20-membered ring ( 1) as the orifice and examined the properties of the complex using NMR and MALDI-TOF mass spectroscopy. The proton NMR shows a broad resonance corresponding to endohedral NH 3 at delta H = -12.3 ppm relative to TMS. This resonance was seen to narrow when a (14)N decoupling frequency was applied. MALDI spectroscopy confirmed the presence of both 1 ( m/ z = 1172) and 1 + NH 3 ( m/ z = 1189), and integrated intensities of MALDI peak trains and NMR resonances indicate an incorporation fraction of 35-50% under our experimental conditions. NMR observations showed a diminished incorporation fraction after 6 months of storage at -10 degrees C, which indicates that ammonia slowly escapes from the open-cage fullerene.
Whitener
Keith E
KE
Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, USA.
Frunzi
Michael
M
Iwamatsu
Sho-ichi
S
Murata
Shizuaki
S
Cross
R James
RJ
Saunders
Martin
M
D000641:Ammonia / Q000737:chemistry*; D037741:Fullerenes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards; D008968:Molecular Conformation; D012015:Reference Standards; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
D037741:Fullerenes; D000641:Ammonia