An Expanded Family of Dysprosium–Scandium Mixed‐Metal Nitride Clusterfullerenes: The Role of the Lanthanide Metal on the Carbon Cage Size Distribution

Abstract

A large family of dysprosium-scandium (Dy-Sc) mixed-metal nitride clusterfullerenes (MMNCFs), Dy(x)Sc(3-x)N@C2n (x = 1, 2, 2n = 68, 70, 76-86) have been successfully synthesized and isolated. Among these, the C70 and C82-based MMNCFs are two new cages that have never been isolated for MMNCFs. Synthesis of Dy(x)Sc(3-x)N@C2n was accomplished by the "selective organic solid" route using guanidinium thiocyanate as the nitrogen source, and their isolation was fulfilled by recycling HPLC. UV/Vis-NIR spectroscopic study indicates that almost all Dy(x)Sc(3-x)N@C2n MMNCFs are kinetically stable fullerenes with optical band gaps beyond 1 eV. This feature is distinctly different to their counterparts Dy3N@C2n (78≤2n≤88), whose for optical band-gaps are below 1 eV for relatively large cages such as C84 and C86. An FTIR spectroscopic study in combination with DFT calculations enables reasonable assignments of the cage isomeric structures of all isolated Dy(x)Sc(3-x)N@C2n (x = 1, 2, 2n = 68, 70, 76-86) MMNCFs. The carbon cage size distribution of Dy(x)Sc(3-x)N@C2n (2n = 68, 70, 76-86) is compared to the reported Dy3N@C2n (78≤2n≤8) homogeneous NCF and Dy(x)Sc(3-x)N@C2n (78≤2n≤88) MMNCF families, revealing that the medium-sized Dy metal plays a crucial role on the expanded cage size distribution of MMNCFs. As a result, Dy(x)Sc(3-x)N@C2n MMNCFs are the largest MMNCF family reported to date.

Blending Non‐Group‐3 Transition Metal and Rare‐Earth Metal into a C80 Fullerene Cage with D5h Symmetry

“…On the other hand, the relative yields of V x Sc 3− x N@ D 5 h ‐C 80 ( x= 1, 2) to their corresponding first isomer V x Sc 3− x N@ I h ‐C 80 ( x= 1, 2) was also estimated, which is 1:1.3 (V 2 ScN@ D 5 h ‐C 80 :V 2 ScN@ I h ‐C 80 ) and 1:2.4 (VSc 2 N@ D 5 h ‐C 80 :VSc 2 N@ I h ‐C 80 ),respectively. Interestingly, the tendency that the yield of V x Sc 3− x N@ D 5 h ‐C 80 ( x= 1, 2) as the second isomer is lower than that of the first isomers V x Sc 3− x N@ I h ‐C 80 ( x= 1, 2) is in line with the reported rare‐earth metal‐based MMNCFs M x Sc 3− x N@C 80 (M=Gd, Dy), suggesting that the concurrent encapsulation of V atom within I h ‐ or D 5 h ‐C 80 cage may follow the similar mechanism to those for rare‐earth metal‐based clusterfullerenes.…”

“…The yield of individual fullerene can be estimated from the integrated area of its corresponding HPLC peak, which provides valuable information on its formation probability . The relative yield of V 2 ScN@ D 5 h ‐C 80 :VSc 2 N@ D 5 h ‐C 80 :Sc 3 N@ D 5 h ‐C 80 is estimated to be 1:3.6:169.2 (see the Supporting Information, section S2).…”

“…Compared to mixed metal nitride clusterfullerenes (MMNCFs) containing rare‐earth metals only such as M x Sc 3− x N@ D 5 h ‐C 80 ( x= 1, 2, M=Gd, Dy), the relative yield of V 2 ScN@ D 5 h ‐C 80 :Sc 3 N@ D 5 h ‐C 80 is ca. 60 times lower than those of Gd 2 ScN@ D 5 h ‐C 80 :Sc 3 N@ D 5 h ‐C 80 (1:2.8) and Dy 2 ScN@ D 5 h ‐C 80 :Sc 3 N@ D 5 h ‐C 80 (1:2.7; Supporting Information, Table S2) . This suggests that entrapping V atoms into the D 5 h ‐C 80 cage is more difficult than the cases of rare‐earth metals.…”

Evaluation of bonding, electron affinity, and optical properties of M@C28 (M = Zr, Hf, Th, and U): Role of d‐ and f‐orbitals in endohedral fullerenes from relativistic DFT calculations

“…Endohedral fullerenes containing interstitial metal atoms have attracted particular interest owing to their novel properties with potential applications in biomedicine and photovoltaics among others issues. The interstitial metal atoms modify the behavior of the external carbon cage, thereby resulting in a different chemical reactivity compared to the corresponding hollow cage . Endohedral metallofullerenes (EMF) can encapsulate actinide metals, including uranium and thorium, leading to molecular materials displaying fullerene stability as well as the chemistry of the interstitial actinide atom.…”

Methan als Selektivitätsverstärker in der Lichtbogensynthese von endohedralen Fullerenen: selektive Synthese des Einzelmolekülmagneten Dy2TiC@C80 und dessen Kongener Dy2TiC2@C80

“…Leider ist die selektive Synthese von heterometallischen Nitridclusterfullerenen nicht mçglich. Bei der Lichtbogensynthese des Dy-Sc-Systems entsteht immer ein Gemisch der Dy x Sc 3Àx N@C 2n -Verbindungen (x = 0-3) mit jeweils unterschiedlicher Isomerie als auch weiteren Käfiggrçßen, [25] . .…”