Fourier transform infrared spectrum of ammonia adsorbed on C-60 films

Fourier transform infrared (FTIR) spectra of ammonia adsorbed on high surfa ce area evaporated C-60 films were investigated at 170-180 K. Absorptions w ere found in the nu(1), nu(2), nu(3) and nu(4) regions. The frequencies of nu(1), nu(4) and nu(3) absorption bands are shifted to lower values and the frequency of nu(2) to higher value compared to the gas phase. An additiona l band at 542 cm(-1) assigned to the rocking mode, usually found in solid a mmonia, was also observed. The largest shift, 196-160 cm(-1) towards higher frequencies, was found for the nu(2) band. This led to the conclusion that the ammonia molecule is attached to the surface through the lone pair elec trons of the nitrogen where partial donation to the C-60 surface occurs. (C ) 2000 Elsevier Science B.V, All rights reserved.