Crystal and electronic structure of solid C76

Quantitative Electron Crystallographic Determinations of Higher Fullerenes in the Hexagonal Close Packed Polymorph

“…11,12 These results also can be correlated to observations for pure C60 and C70. While the nearly spherical C84 in a single molecular form may prefer the fcc structure, the presence of two isomers may also promote the hcp packing in a way found when just 2% of C70 is cocrystallized in a solid solution 5 with C60.…”

Studies of fullerenes by the excitation, emission, and scattering of electrons

“…This conclusion both in their pristine state and intercalated with alkali 82 is backed up by autoionisation studies (not shown) metals, in which the samples were in the form of a where even with the photon energy tuned to the mixture of more than one structural isomer. Under energy of one of the Tm(III) 4d→4f excitation this category fall studies of C [147][148][149], C 76 78 11 channels, no emission corresponding to a 4f final [149,150], C [151], C [149], C [149,152], and 80 82 84 state is observed. Unlike other systems containing C [149].…”

SolidC76: NMR studies of molecular dynamics

“…1,2 The anomalies of solid C 76 around this temperature have also been found in the recent x-ray-diffraction ͑XDR͒ experiments, 17 in which the kinks were observed in the temperature dependence of the lattice constant, and molecular-dynamics calculation study. 18 However, the XDR and transmission-electron microscopy ͑TEM͒ of C 76 have shown no structural change down to 77 K. 7,9,17 Therefore, at the present, we cannot rule out another possibility such as a glassy phase transition around 170-135 K. Here, the glassy transition means a freezing of the dynamically disordered states existing in the higher temperature range.…”

“…4 The corresponding values in the sublimed C 76 ͑ 0 ϭ1.8 psec and T 0 ϭ1350 K͒ above 170 K seems to be close to those of the high-temperature phase in C 60 rather than those of the lowtemperature phase: C 76 molecules may be dynamically disordered above 170 K. This result is consistent with a facecentered-cubic ͑fcc͒ structure at room temperature already reported. 7,9 Around 170-135 K, the molecular rotation rapidly freezes, suggesting an orientational ordering transition as in solid C 60 . 1,2 The anomalies of solid C 76 around this temperature have also been found in the recent x-ray-diffraction ͑XDR͒ experiments, 17 in which the kinks were observed in the temperature dependence of the lattice constant, and molecular-dynamics calculation study.…”

“…With increasing temperature the freedom of the molecular rotation around the molecular long axis melts first at ϳ280 K, and then the melting phase even around the short axis starts to appear at 340 K. 5,6 However the study of the third smallest fullerene C 76 has been very limited compared with those of C 60 and C 70 , and no phase transition has been reported so far. [7][8][9] A fullerene consisting of 76 carbon atoms, C 76 , has a chiral D 2 structure, 10 which is fairly flat and deviates from a sphere; the length of the three principal axes is calculated to be 8.75, 7.50, and 6.54 Å. 11 The crystal may be a mixture of right-handed and left-handed chiral molecules.…”