The reactions of benzene on Al-100(+) have been investigated as a function of cluster temperature (300-1100 K) and relative kinetic energy (1-14 eV) by low-energy ion-beam methods and mass spectrometry. Benzene chemisorbs on both solid and liquid aluminum clusters to generate Al100C6D6+. A series of Al-100-n(+) (n = 1, 2, 3, ...) products was also observed. As the cluster temperature was raised above the melting temperature of Al-100(+), the Al100C6D6+ product dehydrogenates to form Al100C6D4+, Al100C6D2+, and Al100C6+. The degree of dehydrogenation was measured as a function of temperature. Very little Al100C6D2+ was observed, suggesting that the losses of the second and third D-2 molecules are coordinated.