【摘 要】
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The aromatic character of divalent three, five and seven-membered rings C2H2M,C4H4 and C6H6M(M=C,Si, Ge, Sn and Pb) is investigated through magnetic and geometr
【机 构】
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Payame Noor University,Department of Chemistry
论文部分内容阅读
The aromatic character of divalent three, five and seven-membered rings C2H2M,C4H4 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.
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