Contrasting Behaviors of Metal Fullerides C₆₀Rh_x and C₆₀M_x (M = La, Y) in the Metallofullerene Formation by Laser Ablation

Abstract

Contrasting behaviors of Rh with Y(La) in the formation of metallofullerenes by excimer laser ablation of metal fullerides C60Rh x and C60M x (M = La, Y) were observed. For Rh, two sequences of rhodium metallofullerenes, C2 n Rh and C2 n +1Rh with even and odd numbers of carbon atoms, are formed in both the negative and positive ion channels, but for La and Y, only the metallofullerene sequence with even numbers of carbon atoms is formed and only in the positive ion channel. Evidence of the encapsulation of La and Y atoms in fullerene cages forming endohedral fullerenes has been observed, whereas the Rh atom is most probably incorporated into the network of the fullerene cage or pseudo-fullerene forming substitutional metallofullerenes. Density functional theory calculation was performed to determine the structures of the model metallofullerenes C53Rh and C54M (M = Rh and Y). The calculated results are in general consistent with the experimental observations.

Theoretical Studies of Substitutionally Doped Single-Walled Nanotubes

“…A close analysis of the energy changes associated with the physisorption process reveals that C 169 Pt(w) has the strongest interaction with C 2 H 4 [35,36]. These distances are in agreement with those reported for the adsorption of ethylene onto an Ir-doped fullerene [97].…”

“…The doping of the sidewall of SWCNTs with transition metals, however, remains to be achieved [91][92][93][94][95], despite the fact that the closely related transition metal-doped fullerenes have been synthesized and characterized [96][97][98][99][100][101][102][103]. Pt-, Ir-, Rh-, La-, Sm-, Sc-, and Y-doped fullerenes have been prepared via laser ablation or ionization, typically detected and characterized by mass spectrometry.…”

Structure and Stability of Networked Metallofullerenes of the Transition Metals

“…For the larger cages, the endohedral and exohedral structures dominate. 18,19 For the mid-and late-transition metals, the stability of the networked metallofullerenes seems to increase 10 and larger networked metallofullerenes such as MC 59 have been observed for metals from group 8 (Fe 13,14 ), 9 (Co,13,14 Rh, [13][14][15][16] Ir 13,14,20 ) and 10 (Ni, 13,14,16 Pt 16,20 ).…”

“…Theory may complement the lack of experimental information. Density functional theory (DFT) has been applied in the study of all the above-mentioned networked metallofullerenes 15,17,[20][21][22][23][24] in addition to other networked metallofullerenes. [25][26][27] Most of these works involve studies of the geometric and electronic structure of single substitutional metallofullerenes or comparison among a few of the experimentally observed compounds.…”

Defected and Substitutionally Doped Nanotubes: Applications in Biosystems, Sensors, Nanoelectronics, and Catalysis

“…Although physisorption of transition metals onto CNTs is a known process, substitutional doping in which the transition metal atom is embedded into the sidewall remains an unsolved challenge in nanoscience, although some researchers have proposed that this transformation may be assisted by the presence of vacancy defects (Yang et al 2006;Zhuang et al 2008). The corresponding transition metal substitutionally doped fullerenes, however, have been prepared experimentally and characterized (Branz et al 1998;Poblet et al 1999;Kong et al 2003). For example, d-block transition metals Pt-, Ir-, Rh-, Sc-, and Y-, and f-block La-and Sm-doped fullerenes have been synthesized by laser ablation or ionization and can be detected by mass spectrometry.…”