科研之友
微信
新浪微博
Facebook
分享链接
摘要
The products of 1,2-cycloaddition of dihalocarbene to the bowl-shaped corannulene (C20H10, 1) have been isolated in the solid state and fully characterized. The first X-ray diffraction analysis of mono- and bis-adducts, C20H10CCl2 (2) and C20H10(CCl2)(2) (3), has been accomplished to reveal structural changes of the corannulene framework upon addition of dichlorocarbene groups as well as to show variations in the solid state packing of the functionalized polar bowls. For the monoadduct 2, the Cs symmetric molecular structure with the hub attachment of the CCl2 group to a bowl was confirmed. In the solid state, the polar C20H10CCl2 molecules form one-dimensional (1D) columns based on strong concave-convex pi center dot center dot center dot pi interactions (ca. 3.36-3.37 angstrom). The resulting polar 1D stacks in 2 are all oriented in the same direction to form polar crystals. The addition of the second dichlorocarbene group in C20H10(CCl2)(2) caused the drastic reduction of the dipole moment from 3.7 D in 2 to 2.0 D in 3, which was also accompanied by a change of the solid state packing pattern. For the bis-adduct 3, two different polymorphs were obtained under different crystallization conditions, solution (3a) vs gas-phase deposition (3b). Both crystal structures are based on bimolecular aggregation of C20H10(CCl2)(2) molecules held by C-H center dot center dot center dot Cl interactions (2.988 angstrom for 3a and 2.891 angstrom for 3b). The resulting dimers show different packing in the solid state structures of 3a and 3b.
- 出版日期2015-2
