Deviation from the Planaritya Large Dy₃N Cluster Encapsulated in an I_h-C₈₀ Cage:  An X-ray Crystallographic and Vibrational Spectroscopic Study

Abstract

The high-yield synthesis of Dy3N@C80 (I) opens the possibility of characterizing its molecular and vibrational structures. We report on the structure determination of Dy3N@C80 (I) by X-ray crystallographic study of single crystal of Dy3N@C80.Ni(OEP).2C6H6, revealing a nearly planar Dy3N cluster encapsulated in an Ih-C80 cage. The vibrational structure of Dy3N@C80 (I) is studied by Fourier transform infrared (FTIR) and Raman spectroscopy in combination with force-field calculations. A correlation was found between the antisymmetric metal-nitrogen stretching vibration and the structure of the M3N cluster of M3N@C80 (I) (M = Y, Gd, Tb, Dy, Ho, Er, Tm). Moreover, a stronger interaction between the encaged nitride cluster and the C80 carbon cage was found in the class II M3N@C80 (I) (M = Y, Gd, Tb, Dy, Ho, Er, Tm) than in Sc3N@C80 (I). This study demonstrates that the cluster size plays the dominating role in the structure of the M3N cluster in M3N@C80 (I).

Investigation ofGd3N@C2n (40≤n≤44)Burke1, Chan2, Williams3 et al. 2010Phys. Rev. B28070View full textAdd to dashboardCite

“…The 165 cm −1 mode for Gd 3 N@C 80 compares well with previous experimental results. 2,36,38 This particular mode is similar to the vibrational mode reported for Gd@C 82 , which exhibits a Raman frequency at 155 cm −1 . 2,24 When plotting this mode against the square root of the reciprocal reduced mass, ͓1 / m reduced ͑Gd 3 N-C 2n ͔͒ 1/2 , a linear trend is found ͑Fig.…”

“…Other groups have seen evidence for the formation of a M 3 N-C 80 bond which induces a significant reduction of the ideal I h −C 80 symmetry. 2,37,38 A peak at 83.6 cm −1 appears to be the wagging mode of the nitrogen atom through the Gd 3 plane, predicted by theory. 27 Other COM modes are identified, where the cage-core complex translates relative to the other.…”

“…2,8 Although no x-ray or NMR data has been conducted for Gd 3 which identifies the C 80 cage modes. The frequency of the M-cage stretching mode is increased to 195.6 cm −1 for the yttrium complex, 2,38 due to the change in reduced mass ͑32.7% decrease͒, and decreased to 155.9 cm −1 for the lutetium complex, due to the change in reduced mass ͑7.0% increase͒. Assuming harmonic motion, a force constant k = 12.8Ϯ 0.37 N / cm can be derived, and it can be concluded that the frequency shift of the M 3 N-C 80 oscillator is solely due to the change in metal mass.…”

“…Therefore, UFF calculations of Gd 3 N@C 80 and Gd 3 N were conducted and compared with both experimental compares well with previous theoretical calculations. 38 The intrinsic Gd 3 N molecule has six vibrational modes, two of which are degenerate. One mode with A 1 symmetry is a breathing mode or Gd-N symmetric stretch, where the Gd triangle expands and contracts.…”

Femtosecond X-ray-induced fragmentation of fullerenes

“…This can be compared, as a rough estimate, to the energy release from the explosion of a triangular planar configuration of three Ho + ions surrounding a central N atom (54). If we consider the Ho-N distance to be 2.1Å, based on prior work (55) and if we consider N as a neutral atom, the kinetic energy released per fragment will be 4.0 eV.…”