A quantum chemical study of silsesquioxanes: H8Si8O12, Me8Si8O12, H@Me8Si8O12, He@Me8Si8O (12) (+) , and He@Me8Si8O12

作者：Semenov S G^*; Bedrina M E

来源：Journal of Structural Chemistry, 2013, 54(1): 159-163.

DOI：10.1134/S002247661301023X

• silsesquioxanes
• endocomplexes
• helium
• cubic symmetry
• structure
• polarizability
• PBE0
• B3LYP
• cc-pVTZ
• MP2

Quantum chemical PBE0 and B3LYP/cc-pVTZ, PBE0, B3LYP, RHF and MP2/6-31G(d,p) methods are employed to calculate the structural parameters of octa(silsesquioxane) H8Si8O12 and octa(methylsilsesquioxane) Me8Si8O12. These molecules and complexes H@Me8Si8O12, He@Me8Si8O (12) (+) , and He@Me8Si8O12 have highly symmetric (O (h) ) equilibrium configurations. With the use of the PBE0 method and a cc-pVTZ multicenter basis set common for the complex and its components coincidence is achieved between the calculated polarizability of a free He atom and the experimental value of 0.21 (3) and the polarizability depression of 0.17 (3) was found for He@Me8Si8O12. In order to avoid the false conclusion about molecular symmetry the calculations of the structure of silsesquioxanes must be performed with sufficiently high accuracy (Int = ultrafine and Opt = tight in the use of the GAUSSIAN program).

• 出版日期2013-2