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Structures, Stabilities, and Electronic and Optical Properties of C 58 Fullerene Isomers, Ions, and Metallofullerenes
Author(s) -
Chen DeLi,
Tian Wei Quan,
Feng JiKang,
Sun ChiaChung
Publication year - 2007
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.200600785
Subject(s) - chemistry , fullerene , ion , chemical stability , quantum chemical , chemical shift , cis–trans isomerism , ring (chemistry) , crystallography , computational chemistry , stereochemistry , molecule , organic chemistry
The 1205 classical isomers of fullerene C 58 , as well as one quasi‐fullerene C 58 isomer with a heptagonal ring (labeled as C s :hept) have been investigated by the quantum chemical methods PM3, HCTH/3‐21G, and B3LYP/6‐31G(d). Isomer C 3 v :0001, which has the lowest number of adjacent pentagons, is predicted to be the most stable isomer, but the quasi‐fullerene isomer C s :hept is only 2.50 kcal mol −1 higher in energy. Systematic investigations of the electronic properties of C 3 v :0001 and C s :hept find that the C 3 v :0001 isomer has high vertical electron affinity (3.19 eV). The nucleus‐independent chemical shifts (NICS) value at the center of C s :hept (−5.1 ppm) is more negative than that of C 60 (−2.8 ppm). The NICS value at the center of the heptagonal ring in C s :hept (−2.5 ppm) indicates weakly aromatic character. In contrast, the C 58 6− and C 58 8− ions of the C 3 v :0001 and C s :hept geometries possess large aromatic character, with NICS values between −14.0 and −26.2 ppm. To clarify the thermodynamic stabilities of C 58 isomers at different temperatures, the entropy contributions are taken into account on the basis of the Gibbs energy at the B3LYP/6‐31G(d) level. The C 3 v :0001 isomer prevails in a wide range of temperatures, and the C s :hept isomer is also an important component around 2800 K. The IR spectra of C 58 isomers are simulated to facilitate experimental identification of different isomers. In addition, the electronic spectra and the second‐order hyperpolarizabilities are predicted by ZINDO and the sum‐over‐states model. The static second‐order hyperpolarizability of the C 3 v :0001 isomer is 96.5 % larger than that of C 60 , and its second‐order hyperpolarizabilities at external field frequencies are at least nine times larger than those of C 60 .