Uranium Stabilization of C ₂₈ : A Tetravalent Fullerene

Abstract

Laser vaporization experiments with graphite in a supersonic cluster beam apparatus indicate that the smallest fullerene to form in substantial abundance is C(28). Although ab initio quantum chemical calculations predict that this cluster will favor a tetrahedral cage structure, it is electronically open shell. Further calculations reveal that C(28) in this structure should behave as a sort of hollow superatom with an effective valence of 4. This tetravalence should be exhibited toward chemical bonding both on the outside and on the inside of the cage. Thus, stable closed-shell derivatives of C(28) with large highest occupied molecular orbital-lowest unoccupied molecular orbital gaps should be attainable either by reacting at the four tetrahedral vertices on the outside of the C(28) cage to make, for example, C(28)H(4), or by trapping a tetravalent atom inside the cage to make endothedral fullerenes such as Ti@C(28). An example of this second, inside route to C(28) stabilization is reported here: the laser and carbon-arc production of U@C(28).

Formation and growth of carbon nanostructures: fullerenes, nanoparticles, nanotubes and cones

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Fullerenes: Synthesis and Applications

“…Functionalization can be achieved either through covalent means due to the electrophilic nature of C 60 therefore it is an excellent substrate for nucleophilic addition or non-covalent means which include hydrogen bonding, pie-pie interactions and metal ion coordination (Bethune, , Johnson, Salem, De Vries, & Yannoni, 1993) Therefore fullerene derivatives can be made to be more lipophilic than the basic fullerene and also water-soluble and amphiphilic too (Hummelen et al, 1995;Weaver et al, 1992;Ciotta et al, 2017;Guo et al, 1992;Wang et al, 1993). Buckminsterfullerene (C60) has been functionalized with Polyvinyl pyrollidone (PVP) to produce a water soluble fullerene derivative (Shanboh & Sundaram, 2015) as shown in figure 4 below.…”

Carbon Nanotubes – Imprinted Polymers: Hybrid Materials for Analytical Applications

“…The laser ablation, based on the high energy density of lasers (typically a YAG or CO 2 laser) which is suitable for materials with a high boiling temperature such as carbon, was developed for fullerene and CNT production by Smalley's group (Guo T. et al, 1992;Thess et al, 1996). The laser has sufficiently high energy density not to cleave the target into graphite particles but to vaporize it at the molecular level converting the graphite vapor into amorphous carbon as the starting material of SWNTs (Puretzky et al, 2000;Sen et al, 2000;Kokai et al, 2000).…”