{'fraction_non_alphanumeric': 0.06770833333333333, 'fraction_numerical': 0.03943452380952381, 'mean_word_length': 4.723404255319149, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Accumulating evidence for the selective reactivity of the 6-6 ring fusion of fullerene, C60. Preparation and structure of (.eta.2-C60)Ir(CO)Cl(PPh3)2.cntdot.5C6H6

The recent discovery that C[sub 60] (buckminsterfullerene) can be isolated in macroscopic quantities has led to widespread interest in its chemical and physical properties. C[sub 60] has icosahedral D[sub 5h] symmetry with 20 six-membered rings that are interconnected with 12 five-membered rings. There are two types of C-C bonds within this cluster: one type occurs at the 6-6 ring fusions, while the other occurs at the 6-5 ring fusions. There are no 5-5 ring fusions. Two crystalline derivatives of C[sub 60] have been obtained by addition of transition-metal complexes to the cluster. Addition of osmium tetraoxide and tert-butylpyridine produces C[sub 60]O[sub 2]OsO[sub 2](NC[sub 5]H[sub 4]CMe[sub 3])[sub 2] in which an O[sub 2]Os unit has added across a 6-6 ring fusion in the carbon cluster. Addition of C[sub 60] to (Ph[sub 3]P)[sub 2]Pt(ethylene) results in displacement of ethylene and formation of ([eta][sup 2]-C[sub 60])Pt(PPh[sub 3])[sub 2]. In this complex, the platinum atom is bound to carbon atoms again at a 6-6 ring junction of the carbon cluster. Here the authors report another case of reactivity that involves addition to a C-C bond of a 6-6 ring fusion.