Bond Characterization of a Unique Thiathiophthene Derivative: Combined Charge Density Study and X-ray Absorption Spectroscopy

作者：Chuang Yu Chun; Li Ya Wen; Hsu I Jui; Lee Gene Hsiang; Wang Yu^*

来源：Inorganic Chemistry, 2013, 52(19): 10958-10967.

DOI：10.1021/ic4010455

Thiathiophthene (TTP), a planar molecule with two fused heterocyclic five-membered rings and an essentially linear S-S-S bond, is a molecule of great interest due to its unique chemical bondings. To elucidate the remarkable bonding nature, a combined experimental and theoretical study on the electron density distribution of 2,5-dimethyl-3,4-trimethylene-6a-TTP (1) is investigated based on a multipole model through high-resolution X-ray diffraction data experimentally and on the density functional calculations (DFT) theoretically. In addition, S K-edge X-ray absorption spectroscopy (XAS) is measured to verify the chemical bonding concerning the sulfur atoms. The molecule can be firmly described as 10 pi electron with aromatic character among the eight atoms, S3C3, of the two fused five-membered rings plus three-center four-electron sigma character along the S-S-S bond. Such bonding description is verified with the calculated XAS spectrum, where the pre-edge absorption for transitions from S Is to pi* and sigma* are located. The three-center four-electron S-S-S sigma bond makes the terminal S atoms richer in electron density than the central one.

• 出版日期2013-10-7