Prediction of Heterofullerene Stabilities: A Combined DFT and Chemometric Study of C₅₆Pt₂, C₅₇Pt₂and C₈₁Pt₂

Abstract

A systematic search of the regioisomers of the heterofullerenes, C57Pt2 and C56Pt2, has been carried out by means of density functional calculations to find the most stable structures. Both heterofullerenes incorporate two metal atoms into the fullerene surface. In the case of C57Pt2, one platinum atom substitutes one carbon atom of C60 and the other platinum atom replaces a C--C bond, whereas in C56Pt2 each platinum atom replaces one C--C bond. Several geometric factors were studied, three of which have particularly important effects on the relative stabilities of the regioisomers: the Pt--Pt separation, the number of C--C bonds remaining after substitution, and the type of C--C bond that is substituted. All these factors indicate that the deformation of the carbon framework is a general factor that governs the relative stabilities of the regioisomers. Because a high number of factors affect the stability of the heterofullerenes we also used chemometric techniques in this study. Partial least-squares (PLS) regression was used to establish the structure-energy relationships of C57Pt2 and C56Pt2 heterofullerenes. The understanding gained of the factors that affect the relative isomers stabilities has allowed us to predict the stabilities of larger disubstituted carbon cages, for example, C81Pt2 heterofullerene.

Metallofullerenes as fuel cell electrocatalysts: A theoretical investigation of adsorbates on C59Pt

“…9,10,35,36 Changgeng et al 36 studied several metallofullerenes, not including platinum, by using the local spin density approximation and found structures similar to what other studies, including this one, find for a platinum heterofullerene. Poblet et al, 10 Hayashi et al, 9 and Campanera et al 35 used DFT within various versions of the program ADF. [37][38][39] 3.1.1 The formation of C 59 Pt.…”

Understanding the stability, bonding nature and chemical reactivity of 3d-substituted heterofullerenes C58TM (TM = Sc–Zn) from DFT studies

“…A range of C 59 M compounds of group 6-8 metals were predicted by DFT studies reported by Jensen's group 8 to have sufficient stability for experimental observation. Campanera et al 9 have performed a systematic search of the regioisomers of the heterofullerenes C 57 Pt 2 and C 56 Pt 2 by means of density functional calculations to nd the most stable structures. They found that the deformation of the carbon framework was a general factor for governing the relative stabilities of the regioisomers.…”

Theoretical Studies of Substitutionally Doped Single-Walled Nanotubes

“…Additionally, the synthesis of second-and third-row transition metal-doped fullerenes has been predicted to be attainable via reaction of the corresponding transition metal trichloride (or dichloride) in the presence of chlorine gas (Cl 2 ) and buckminsterfullerene (C 60 ) [105]. Theoretical studies also provide insight into the electronic properties of transition metal-doped fullerenes [106][107][108][109]. In general, the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) in transition metal-doped fullerenes decreases in comparison to the parent fullerene upon introduction of a transition metal atom into the cage [109], resulting in higher conductivity and reactivity [106], and hence suggests similar effects for nanotubes.…”