Electronic Structures of Bis- and Monothiophene Complexes with Fe, Co, Ni: A Density Functional Theory Study

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• 作者：Yunqiao Ding ; Maoxia He ; Yuzhong Niu ; Dengxu Wang ; Yan Cui ; Shengyu Feng
• 刊名：Journal of Physical Chemistry A
• 出版年：2009
• 出版时间：September 24, 2009
• 年：2009
• 卷：113
• 期：38
• 页码：10291-10298
• 全文大小：280K
• 年卷期：v.113,no.38(September 24, 2009)
• ISSN：1520-5215

文摘

A density functional theory study for the bis- and monothiohene complexes of Fe, Co, and Ni (MT₂ and MT, T = thiophene, M = Fe, Co, Ni) was performed to understand their coordination geometries, bonding properties, vibration spectra and singlet excited state spectra. The typical metal coordination exists in the complexes. The Fe−thiophene coordination has the highest stability, with Ni−thiophene being the second highest, and Co−thiophene the lowest. Bisthiophene complexes of Co and Ni prefer to homolytically dissociate to their monothiophene ones and free thiophene. Frequency calculation shows that the ligand−M−ligand asymmetric stretching vibration in bisthiophene complexes shows a strong absorption, at 435.2, 495.7, and 383 cm⁻¹ for Fe(η⁴-T)₂, Co(η²-T)₂ and Ni(η²-T)₂, respectively. The M−S stretching vibration in monothiophene complexes shows a strong absorption in the far-infrared region, at 209, 156, and 150 cm⁻¹ for Fe(η⁴-T), Co(η⁴-T) and Ni(η⁵-T), respectively. The excited state spectra indicate that the characteristic absorption wavelengths of the complexes have a red shift of more than 12.40 eV compared to free thiophene, at 3.54, 1.64, 3.83, 2.75, 1.43, and 2.58 eV for Fe(η⁴-T)₂, Co(η²-T)₂, Ni(η²-T)₂, Fe(η⁴-T), Co(η⁴-T), and Ni(η⁵-T), respectively.