Combining Chirality and Hydrogen Bonding in Methylated Ethylenedithio-Tetrathiafulvalene Primary Diamide Precursors and Radical Cation Salts
Combining Chirality and Hydrogen Bonding in Methylated Ethylenedithio-Tetrathiafulvalene Primary Diamide Precursors and Radical Cation Salts
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DOI：
10.1021/acs.cgd.9b01665
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发表时间：
2020-04-01
影响因子：
3.8
通讯作者：
Avarvari, Narcis
中科院分区：
文献类型：
--
作者：
Mroweh, Nabil;Pop, Flavia;Avarvari, Narcis
甲基和二甲基乙二硫代四硫富瓦烯邻二胺给体Me-EDT-TTF(CONH2)(2)(1a)和DM-EDT-TTF(CONH2)(2)(1b)由相应的双酯前体与氨水溶液直接反应得到。用单晶X射线衍射法对中性(RAc)-1a、(R)-1a和(S，S)-1b给体进行了表征。在非中心对称的P2(1)空间群中结晶的三个化合物中，酰胺基团是无序的，但它们形成了典型的邻二胺基团的分子内氢键。电结晶实验表明，混合价自由基阳离子盐[(S，S)-1b](2)XO4和[(R，R)-1b](2)XO4(X=Cl，Re)在不对称单元中含有四个独立的施主，正电荷主要集中在两个施主上，另外两个是中性的。有机层的拓扑结构为β‘型。单晶电阻率测量表明，[(S，S)-1b](2)ClO_4和[(R，R)-1b](2)ReO_4具有半导体行为，其室温电导率为5×10~(-5)S厘米(~(-1))，激活能E_a接近3000K。扩展休克尔型紧束缚能带结构计算与密度泛函理论计算相结合，与半导体行为相一致，表明是局域Mott型半导体，而不是带隙半导体。
Methyl- and dimethyl-ethylenedithio-tetrathiafulvalene ortho-diamide donors Me-EDT-TTF(CONH2)(2) (1a) and DM-EDT-TTF(CONH2)(2)(1b) have been prepared by the direct reaction of the corresponding diester precursors with aqueous ammonia solutions. The neutral (rac)-1a, (R)-1a, and (S,S)-1b donors have been characterized by single crystal X-ray diffraction. In the three compounds, which crystallized in the non-centrosymmetric monoclinic space group P2(1), the amide groups are disordered, yet they form the classical intramolecular hydrogen bond for such an ortho-diamide motif. Electrocrystallization experiments afforded the mixed valence radical cation salts [(S,S)-1b](2)XO4 and [(R,R)-1b](2)XO4 (X = Cl, Re) containing four independent donors in the asymmetric unit, with the positive charge localized essentially on two donors, while the two others are neutral. The topology of the organic layer is of beta'-type. Single crystal resistivity measurements show semiconducting behavior for [(S,S)-1b](2)ClO4 and [(R,R)-1b](2)ReO4, with a room temperature conductivity of 5 x 10(-5) S cm(-1) and activation energies E-a approximate to 3000 K. Tight-binding band structure calculations of extended Huckel type in combination with density functional theory calculations are in agreement with the semiconducting behavior and suggest a localized Mott type semiconductor rather than a band gap semiconductor.