Тип публикации: статья из журнала
Год издания: 2009
Ключевые слова: Co/C60 mixtures, Local atomic structure, dft, complex compounds
Аннотация: The main features of the local atomic structure of novel Con(C60)x (n=1-8, x=1-3) complexes and Con clusters as well were studied using the ab initio GGA calculations for a set of low and high energy isomers in different spin states. It is shown that high-spin low-symmetry structure of free-standing Con clusters is determined by JaПоказать полностьюhn-Teller distortions. For the Co(C60)x (x=1-3) isomers the spin state S=1/2 is energetically preferable whereas the low energy isomers of Co2(C60)x (x=1-3) have an intermediate spin state of S=1. The ?2 (6-6 edge of C60) type of cobalt ion coordination is preferable for both n=1 and n=2 cases. The ?2 (coordination with 6-5 edge) and even the ?5 (C5 fragment) types serve as low and high energy intermediates for the cobalt ions migration around the C60 cage. Formation of cobalt dimers can be the final stage of evolution of Con(C60)x atomic structure approaching the equilibrium atomic geometry. For higher n (3-8) the formation of ?2, ?2 or ?1 coordination bonds between Con fragment and C60 molecules through carbon hexagons results in stable complex nanoclusters with nonmonotonic change of average spin momentum upon the number of cobalt atoms in the Con cores. The theoretical results are compared with corresponding experimental data.
Журнал: Журнал Сибирского федерального университета. Серия: Химия
Выпуск журнала: Т. 2, № 2
Номера страниц: 110-132
ISSN журнала: 19982836
Место издания: Красноярск
Издатель: Федеральное государственное автономное образовательное учреждение высшего образования Сибирский федеральный университет