Sc 3 N and Sc 2 C 2 encapsulated B 40 : Smarter than its carbon analogue

Aggregation behavior and non‐covalent functionalization of borofullerenes B28, B38, and B40: A density functional theory investigation

“…The aromaticities of these borofullerenes and their dimers as well as trimers were further investigated by calculating the NICS values at the cage centers. Figure 1 shows that all the isolated cages are highly aromatic, as suggested by the negative NICS values of −37.7, −46.5, and −39.4 ppm for B 28…”

“…Intuitively, the face to face interactions between two holes of two cages are expected to be more favored in energy due to the possible formation of maximum number of B-B bridge bonds. Indeed, the most stable B 28 dimer is obtained when one heptagon of a cage rotates 90 and stacks onto the second heptagon of the other cage, with the formation of six new B-B bonds (average length: 1.72 Å, Figure 1A). Similarly, the lowest-energy B 38 dimer is formed by connecting the H 6 holes of two cages via two new B-B intercage bonds of 1.75 Å ( Figure 1B).…”

“…For each host-guest complex, different cage positions and cage orientations inside the CPPs were fully considered. Figure 4 shows the most stable structures of the B 28 CPPs, B 38 CPPs, and B 40 CPPs complexes. The shortest distances between cages and CPPs range from 2.50 to 3.38 Å, close to the B-C van der Waals distance ( Table 1).…”

“…The distance between the molecular centers of [10]CPP and B 28 is 1.61 Å. Clearly, the cavity of [10]CPP is too large for B 28 , so the fullerene moves toward one side, trying to establish a closer contact with the phenylene units.…”

“…, and B 39 − ) [4][5][6][7][8] or theoretically predicted (B 28 , B 44 , and B 46 ), [9][10][11][12][13][14][15][16][17][18][19] among which the B 28 [8,16] and B 38 [9,10] cages are two typical examples. The various structures of their endohedral/ exohedral derivatives are also intensively predicted by theoretical calculations.…”