Dynamics of Paramagnetic Metallofullerenes in Carbon Nanotube Peapods

Abstract

We filled SWNTs with the paramagnetic fullerene Sc@C82 to form peapods. The interfullerene 1D packing distance measured using TEM is d = 1.1 +/- 0.02 nm. The Sc@C82 in SWNT peapods continuously rotated during the 2 s TEM exposure time, and we did not see the Sc atoms. However, Sc@C82 metallofullerenes in MWNT peapods have periods of fixed orientation, indicated by the brief observation of Sc atoms. La@C82 peapods were also prepared and their rotational behavior examined. The interfullerene 1D packing of both La@C82 and Sc@C82 peapods is identical and thus independent of the charge transfer state for these paramagnetic fullerenes. The La@C82 metallofullerenes in the peapods have fixed orientations for extended periods of time, up to 50 s in some cases. The La@C82 spontaneously rotates rapidly between fixed orientations.

Chemical, Electrochemical, and Structural Properties of Endohedral Metallofullerenes

“…These properties can be further modified by incorporation of EMFs into carbon nanotubes to form so-called "peapods". In these, the EMFs modulate the band gap of the nanotubes, and both classical [23][24][25] and nonclassical [6,7,26] metallofullerenes have been inserted in carbon nanotubes. In the case of Gd@C 82 , a combination of elastic strain and charge transfer between the metallofullerene and the nanotube led to a modulation of the band gap by up to 0.5 eV.…”

Electronic Structures, and Optical and Magnetic Properties of Quadruple-Decker Phthalocyanines

“…The chemical shifts of 13 C-NMR, as referred by tetramethylsilane (TMS), were considerably separated around 100-110 ppm, 98 ppm, and 60-70 ppm. The chemical shifts of 14 N-NMR, as referred by NH 3 , were considerably separated around 100-120 ppm, 150-160 ppm, and 190-220 ppm. Assignments of the chemical shifts of 13 C and 14 N-NMR of Sc 3 (Pc) 4 are shown in Figure 6.…”

“…The lack of balance in ESP will cause a slight move in the chemical shifts of 13 C and 14 N-NMR in a low magnetic field. The chemical shifts of 14 N-NMR on the phthalocyanine ring will originate from the nuclear spin interactions of nuclear quadrupole interactions based on EFG and η near the metal and nitrogen ligand. The magnetic interaction will depend on the extent of the charge and spin density distribution of the 3d orbital in the metal and the nitrogen ligand, and the hydrization of the 3d-sp 2 orbital with an overlapping π-orbital on the phthalocyanine rings.…”

“…For instance, single-molecule magnets using copper phthalocyanine [1], nitrogen, and phosphorous atom in fullerene cages, such as N@C 60 [2], and P@C 60 , endohedral metallofullerene, such as Sc 3 N@C 80 [3], Sc 3-x YN@C 80 (CF 3 ) n [4,5], Gd x Sc 3-x N@C 80 [6], HoSc 2 N@C 80 [7], LnSc 2 N@C 80 [8], (Sc 3 N@C 80 ) 2 dimmer [9], scandium oxide endohedral metallofullerenes Sc 4 O 2 @C 80 (CF 3 ) n , Sc 4 O 2 @C 80 [10,11], and endohedral metallofullerene encapsulated within single-walled-carbon nanotube (SWCNTs) as peapods [12][13][14], were applied for controlling the magnetic interaction with entanglement of quantum spin in the spinlattice relaxation process. Experimental verification of spintronics, and nuclear magnetic resonance (NMR) quantum computers using single nitrogen vacancy defects in the center of diamonds [15], perfluorobutadienyl iron complex [16], nitrogen endohedral fullerenes, vanadium phthalocyanines [17], and single-molecule magnets [18,19] were performed for analyzing spin dynamics, Rabi oscillation, and entanglement of nuclear spin as quantum bits in quantum algorithm calculation.…”

“…Especially, the magnetic parameters of the chemical shift of 13 C-NMR, 14 N-NMR, g-tensor of ESR, and UV-VIS-NIR spectra of the quadruple-decker phthalocyanine using 3d transition metals such as scandium, yttrium, and lanthanum atoms will be investigated by quantum calculation. The magnetic mechanism will be explained on the basis of nuclear spin interaction, spin-local interaction, nuclear-spin interaction, and nuclear quadrupole interaction based on EFG and η related with charge density distribution with the overlapping π-orbital on the phthalocyanine ring.…”