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)

查看全文 作　　者：Vessally [1]E;Nikoorazm [2]M;Ramazani [3]A 机构地区：[1]Tayame Noor University,Zanjan Branch,伊朗Zanjan;[2]Department of Chemistry,University of Ilam,伊朗Ilam;[3]Department of Chemistry,Zanjan University,伊朗Zanjan 出　　处：《无机化学学报》索引2008年第24卷第4期,共5页 基　　金：Payame Noor University, Zanjan Branch foundations(伊朗)资助项目 摘　　要：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. 关 键 词：卡宾 硅烯 锗烯 锡烯 铅烯 芳香特性 NICS计算