Thermodynamically and kinetically stable isomers of the C88 and C90 fullerenes

Electronic Properties and 13C NMR Structural Study of Y3N@C88

“…5,6 However, C 88 with D 2 (35) symmetry is not included in this group. Computational calculations (DFT) summarized in Figure 3 suggest that the neutral IPR D 2 (35)-C 88 has a small HOMO-LUMO gap (1.27 eV), indicating the lower stability of the neutral D 2 (35)-C 88 cage.…”

Isolation of a Small Carbon Nanotube: The Surprising Appearance of D5h(1)‐C90

“…[18,20] To provide insight into the nature of the interactions between the fullerene cage of D 5h (1)-C 90 and the metalloporphyrin, we obtained individual electrostatic potential maps of D 5h (1)-C 90 and [Ni II (oep)] at the B3LYP/6-31G(d,p) level of density functional theory ( Figure 6). [8] The central belt of hexagons in D 5h (1)-C 90 shows a region of significant positive potential as indicated by the deep-blue coloration (Figure 6 b). In contrast, the central N 4 region of [Ni II (oep)] is an area of negative potential, as denoted by the red coloration (Figure 6 a).…”

“…[4] Several computational studies have been performed to better understand which specific isomers are expected to be stable. [5][6][7][8] Slanina et al concluded from semiempirical quantum-chemical calculations that the C 2 (45), C 2v (46), C s (35), C 2 (18), and C 1 (9) isomers are likely to be the most stable at the temperatures used for C 90 production. [6] Computations at the B3LYP/6-31G level by Sun indicated that the C 2 (45) isomer was the most stable, and C 2 (28), C 1 (30), C 1 (32), C s (35), C 2 (40), and C 2v (46) were other stable isomers.…”

“…[7] Watanabe et al performed PM3 computations and concluded that there are 11 isomers (D 5h (1), C 1 (27), C 2 (28), C 1 (29), C 1 (30), C 1 (31), C 1 (32), C s (34), C s (35), C 2 (45), and C 2v (46)) that are kinetically as well as thermodynamically stable. [8] Some adducts of C 90 have also been structurally identified. Recently, a trifluoromethyl adduct of C 90 , C 90 (CF 3 ) 12 , which was synthesized by the free-radical addition of CF 3 I to a mixture of higher fullerenes, was shown through 19 F NMR spectroscopy to utilize the C 1 (32)-C 90 cage.…”

Bindungsmuster zweier C90‐Isomere, bestimmt durch Strukturaufklärung von C90Cl32

“…[9] Nach quantenchemischen Rechnungen sollte allerdings das Isomer 45 (C 2 ) die stabilste Spezies sein, gefolgt von den Isomeren 46 (C 2v ) und 35 (C s ). [10,11,14] Daraufhin wurden die publizierten experimentellen NMR-Daten für die Hauptfraktion alternativ interpretiert, demzufolge eine Mischung der Isomere 46 und 35 vorlag. [10,11] Daher ist die Isolierung von C 90 Cl 32 als Chlorderivat des C 2v -C 90 -Isomers 46 nicht überraschend; allerdings lassen unsere kristallographischen Daten auf das Vorliegen eines anderen C 90 Cl 32 [7] Die Verfeinerung der relativen Besetzung der fehlgeordneten C-Atome ergab einen näherungsweisen Gehalt an C 90 Cl 32 -Molekülen mit dem Kohlenstoffkäfig von Isomer 34 von 28(4) % für Struktur I und 17(2) % für Struktur II.…”