AROMATIC CHARACTER STUDIES ON CALICENE AND ITS DERIVATIVES CONTAINING HEAVIER ATOMS VIA NUCLEAR INDEPENDENT CHEMICAL SHIFTS (NICS)

作者：Vessally E^*

来源：Phosphorus, Sulfur, and Silicon and the Related Elements, 2010, 185(1): 187-192.

DOI：10.1080/10426500902758352

• Aromatic character
• calicene
• cyclopropenylidenecyclopentadiene
• heavy atoms
• molecular structure
• NICS

DFT calculations were carried out on the molecular structure of calicene and its derivatives containing heavy atoms, 1(X) and 2(X) (X=C, Si, Ge and Sn), using 6-311+G** basis set in the GAUSSIAN 98 program. The aromatic character of 1(X) and 2(X) was investigated through the magnetic and the geometric criteria. From a geometric view, the molecules, 1(C), 1(Si), 1(Ge), 1(Sn) and 2(Si) have completed electron current in the three-member ring, while the molecules 2(Ge) and 2(Sn) have completed electron current in the five-member ring. Nuclear independent chemical shifts NICS (0.5) calculations indicated an aromatic character in both three and five rings of 1(X) and 2(X), which was decreased from X=C to X=Sn (except for 1(Sn)). However, a non-aromatic and an aromatic character at three- and five-membered ring were observed for 2(Sn), respectively.

• 出版日期2010