Premium
Biologically active fullerene derivatives: Computations of structures, energetics, and vibrations of C 60 (OH) x and C 60 (NO 2 ) y
Author(s) -
Slanina Zdeněk,
Zhao Xiang,
Chiang Long Y.,
Ōsawa Eiji
Publication year - 1999
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/(sici)1097-461x(1999)74:3<343::aid-qua7>3.0.co;2-s
Subject(s) - fullerene , chemistry , computational chemistry , bond dissociation energy , dissociation (chemistry) , nitro , fullerene chemistry , chemical physics , organic chemistry , alkyl
This article reports quantum‐chemical semiempirical computations of selected multihydroxy and multinitro derivatives of C 60 . Polyhydroxylated fullerenes have been known for their efficient free‐radical scavenging activity and promising results in reducing the concentration of free radicals in pathological blood and in inhibiting the growth of abnormal cells. Nitro‐fullerenes are directly linked to hydroxy‐fullerenes as polyhydroxylated fullerenes can be produced through hydrolysis of polynitro‐fullerenes. In spite of this considerable biological application potential, microscopic knowledge of the systems is very limited. This study thus supplies quantum‐chemical semiempirical (primarily PM3) calculations of the structure and energetics for selected hydroxy‐ and nitro‐fullerenes. The configurational sampling of C 60 (OH) x extends from x =2 to x =36. The computations offer a useful insight into the molecular structure, energetics, and possible stability measures. It is suggested that thermodynamic stability could be measured through a partial dissociation heat. Among the computed structures, C 60 (OH) 6 and C 60 (OH) 18 exhibit the best value of the partial dissociation heat. With nitro‐fullerenes, tetra‐nitro derivatives were computed here. The computations follow the finding for dinitro derivatives that low‐energy structures have either the two nitro groups placed in the para position on one hexagon or added to one 6/6 (double) bond of the cage. The lowest tetra‐nitro species found has the para–para arrangement applied to two hexagons separated by one pentagon. Hydroxy‐ and nitro‐fullerenes do not exhibit the highest topologically possible symmetry, that is, symmetry is lowered due to nonbonding interactions. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 74: 343–349, 1999