PHYSICAL-CHEMISTRY - ON THE POSSIBILITY OF EXISTENCE OF ETA(5)-PI-COMPLEXES OF C-60 FULLERENE - PI-COMPLEXES WITH SILICON

Citation
Al. Chistyakov et Iv. Stankevich, PHYSICAL-CHEMISTRY - ON THE POSSIBILITY OF EXISTENCE OF ETA(5)-PI-COMPLEXES OF C-60 FULLERENE - PI-COMPLEXES WITH SILICON, Russian chemical bulletin, 45(10), 1996, pp. 2294-2301
Citations number
16
Categorie Soggetti
Chemistry
Journal title
ISSN journal
10665285
Volume
45
Issue
10
Year of publication
1996
Pages
2294 - 2301
Database
ISI
SICI code
1066-5285(1996)45:10<2294:P-OTPO>2.0.ZU;2-K
Abstract
Qualitative estimates of possibility of the formation of fullerene eta (5)-pi-complexes have been carried out by the MNDO/PM3 method. It was shown, as exemplified by the C-60 cluster, that the introduction of fi ve univalent functional groups R (R = H, Cl, Br) to alpha-positions of a separate pentagon of C-60 with the formation of [R(5)C(60)](-) anio ns results in a pronounced increase in the pi-electron density on the atoms of this five-membered cycle and more favorable conditions for th e formation of pi-bonds with the eta(5)-ligand. The nature of the inte raction between the atoms of the separate cycle in [R(5)C(60)](-) anio n and eta(5)-ligand was analyzed by the example of hypothetical sandwi ch systems R(5)C(60)SiCp. Half-sandwich complexes R(5)C(60)SiX (X = H, CI) were also investigated. The local energy minima were found on the potential energy surfaces (PES) of systems R(5)C(60)SiCp and R(5)C(60 ),SiX with C-5v symmetry. These systems transform barrirlessly into et a(5)-pi-complexes with the angular structure if the symmetry restricti ons are removed. The most favorable conditions for eta(5)-pi-complexes of R(5)C(60) to form are realized for R = H. The results obtained wer e compared to those of semiempirical and nonempirical calculations of bis (cyclopentadienyl) silicon.