Non-IPR endohedral fullerene Yb@C76: density functional theory characterization

Abstract

With a combined methodology of quantum chemistry and statistical mechanics, two Yb@C 76 isomers are disclosed to possess novel fullerene structures which contain one pair of adjacent pentagons and are related by a single Stone-Wales transformation.Fullerenes synthesized to date satisfy the isolated-pentagon rule (IPR), which states that each pentagon on a fullerene cage should be surrounded by hexagons in a stable fullerene isomer. 1,2 However, non-IPR fullerene cages with abutting pentagons are also attractive not only because of their unique structures, but also owing to their unusual properties resulting from the high curvatures around the adjacent pentagons. 3 These pure-carbon non-IPR fullerenes are always unstable and synthetically unattainable in the experiments, due to enhanced steric strain (steric effect) and resonance destabilization pertaining to the pentalene-type 8p-electron system (electronic effect). 4 Fortunately, through exohedral derivatization or endohedral metal-doping, such non-IPR fullerene cages can be successfully synthesized and isolated. 5,6 These fullerenes with endohedral metaldoping are commonly called endohedral metallofullerenes (EMFs).Since the cage 19150:D 2 -C 76 was identified as the first higher fullerene except C 60 and C 70 , C 76 fullerenes are viewed as a peculiar species and have attracted lots of interest. 2,7 Among 19151 classical fullerene isomers of C 76 , there are only two IPR-satisfying structures available. One IPR cage (19150:D 2 ) 2 is a small chiral IPR fullerene which can be obtained as the pristine fullerene as well as in the form of Sc 2 @C 76 . 7 Another IPR cage (19151:T d ) is the higher symmetry fullerene cage which can be generated and stabilized as Lu 2 @C 76 because electrons transfer from the lutetium atoms to the fullerene cage when encapsulating two Lu atoms. 8 The only non-IPR cage example of C 76 -based EMFs is the mixed metal nitride cluster fullerene, DySc 2 N@C 76 , which was predicted to possess the 17490:C s cage with two pairs of pentagon adjacencies. 9 On the other hand, several species of C 76 -based mono-EMFs, M@C 76 , with divalent M (M ¼ Ca, Sr, Sm, Yb) have been synthesized and isolated. 10 These mono-EMFs usually have more than one isomer, which provides additional opportunities for investigating the metal-cage interactions, physical and chemical properties, and potential applications of EMFs. 11 The diverse isomerism of the divalent EMFs also makes it possible to study the effect of the cage on the electronic structures and properties of the EMFs. However, to our best knowledge, neither experimental nor theoretical effort has been paid upon the cage structures of C 76 -based monoEMFs up to now.Here we report that by combined quantum chemical and statistical thermodynamic methods, two new Yb@C 76 isomers are disclosed to possess non-IPR cage structures, both of them have one pair of pentagon adjacencies and are related by a single Stone-Wales transformation. Moreover, the electronic structures, ionization energies, electron affinitie...

Effects of interfacial structure and polarity on charge transfer between carbonaceous nanomaterials and rutile (110) surface

“…(S3), the nearest space between C 60 and rutile (1 1 0) surface is measured as 2.52 Å. And the CÀC bond length of C 60 is 1.39 and 1.44 Å, respectively, corresponding with our recently reports [35][36][37]. The binding energy (4.17 eV) of C 60 and rutile (1 1 0) is larger than that of graphene and rutile (1 1 0) in the neutral state.…”

Takotsubo cardiomyopathy and microvascular dysfunction: Another diagnostic criteria or predisposing factor?

“…However, few studies are devoted to the different properties between metal‐containing and organically modified fullerene derivatives until now. We have reported that some endohedral metallofullerenes possess the stronger UV–vis–NIR broad band than pristine fullerene cages in recent studies,[18, 19] which encourages a further effort on investigating different physical properties between metal‐containing and organically modified fullerenes. Based on experimental reports, the electronic structures and optical spectra properties of five representative fullerene derivatives (three metal‐containing fullerenes and two organically modified ones), that is, Sc 3 N@C 80 , Pd{C 60 [P(CH 3 ) 3 ] 2 }, Pt(C 60 ) 2 , C 60 [C(COOMe) 2 ], and C 2 (C 60 ) 2 have been examined in this work.…”

Fullerenes

“…107 Two Yb@C 76 isomers obtained experimentally have been found to possess the novel non-IPR cages with one pair of adjacent pentagons. 108 The electronic structure and thermodynamic stability of dimetallofullerene Lu 2 @C 76 have been investigated by means of a combined quantum chemical and statistical thermodynamic method. It was found that Lu 2 @C 76 (T d ), contains a single metal-metal bond between two Lu atoms.…”