Physicochemical properties of pressure-synthesized lithium fullendes.

Li_nC₆₀ fullendes were prepared by high-pressure solid-state reactions and characterized by IR spectroscopy and x-ray diffraction. The results are interpreted in terms of a sequence of phase transformations induced by Li incorporation. At low Li contents, 2 < n < 3, a one-dimensional polymer with an orthorhombic structure is formed. Higher Li contents give rise to the formation of a mixture of dimeric and polymeric phases. At n = 5.7, only a dimeric phase with a triclinic structure is formed. In the range 7.1 < n < 10.1, the size of Li clusters increases and a dimeric monoclinic phase forms. [ABSTRACT FROM AUTHOR]