通过核独立化学位移(NICS)计算研究二价三、五、七元环C_2H_2M,C_4H_4M and C_6H_6M(M=C,Si,Ge,Sn and Pb)的芳香族特性(英文)

• 作 者: Vessally E Nikoorazm M Ramazani A
• 机 构: Payame Noor University Zanjan Branch,Zanjan,伊朗,Department of Chemistry University of Ilam,Ilam,伊朗,D
• 出 处: 无机化学学报
• 发表日期: 2008年04期
• 关键词: 卡宾 硅烯 锗烯 锡烯 singlet aromatic 铅烯 芳香特性 NICS计算 化学位移

The aromatic character of divalent three, five and seven-membered rings C2H2M, C4H4M and C6H6M(M=C, Si, Ge, Sn and Pb) is investigated through magnetic and geometric criteria by Density Functional Theory (DFT )method using 6-311++G(3df,2p) basis set of the GAUSSIAN 98 program. The result of Nucleus-independent Chemical Shifts (NICS) (0.5) calculations show an aromatic character for singlet state of C2H2M(M=C, Si, Ge, Sn and Sn) and nonaromatic character for triplet states of C2H2M(except M=Ge and Pb). NICS (0.5) calculations show nonaromatic character for the singlet state of C4H4C and antiaromatic character for C4H4M(M=Si, Ge, Sn and Pb). In contrast, NICS (0.5) calculations indicate antiaromatic character for the triplet state of C4H4C and nonaromatic character to C4H4M(M=Si, Ge, Sn and Pb). NICS (0.5) calculations show a slightly homoaromatic character for the singlet state of C6H6M and anti-aromatic character for triplet state of C6H6M.

The aromatic character of divalent three, five and seven-membered rings C2H2M, C4H4M and C6H6M (M = C, Si, Ge, Sn and Pb) is investigated through magnetic and geometric criteria by Density Functional Theory (DFT) method using 6-311 The result of Nucleus-independent Chemical Shifts (NICS) (0.5) calculations show an aromatic character for singlet state of C2H2M (M = C, Si, Ge, Sn NICS (0.5) calculations show nonaromatic character for the singlet state of C4H4C and antiaromatic character for C4H4M (M = Si, Ge, Sn and Pb) and nonaromatic character for triplet states of C2H2M (except M = Ge and Pb) NICS (0.5) calculations show a slightly homoaromatic character for the singlet state of C14. C6H6M and anti-aromatic character for triplet state of C6H6M.