Nickel dithiolenes containing pendant thiophene units: precursors to dithiolene–polythiophene hybrid materials
作者:Tania Anjos、Susan J. Roberts-Bleming、Adam Charlton、Neil Robertson、Andrew R. Mount、Simon J. Coles、Michael B. Hursthouse、Maher Kalaji、Patrick J. Murphy
DOI:10.1039/b714372a
日期:——
The synthesis, electrochemical and spectroscopic properties of the new thiophene-substituted metal dithiolene complexes [Ni(b-3ted)2] (3) and [NBu4][Ni(b-3ted)2] ([NBu4][3]) are described [b-3ted = bis(3-thienyl)-1,2-ethylenedithiolene] and compared with new studies of the known compounds [Ni(b-2ted)2] (2) and [NBu4][Ni(b-2ted)2] ([NBu4][2]). X-Ray structures were determined for the neutral complexes 2 and 3 and both showed planar nickel dithiolene units with thiophene groups twisted out of the molecular plane, precluding close molecular Ï-stacking. Electrochemical investigations revealed two redox processes corresponding to interconversion between neutral, monoanionic and dianionic species for 3, analogous to 2. Oxidation of 0.1 mM [3]â in CH3CN was shown to give a green molecular film of 3 which, in contrast to as-prepared crystals of 3, showed significant conductivity. Electrochemical polymerisation of 3 carried out at different concentrations resulted in films; electrochemical, SNIFTIRS and UV-Vis results were consistent with incorporation of the intact metal dithiolene complex in these films. In contrast, electrochemical polymerisation of 2 gave a film charateristic of a polymerised thiophene but with no evidence of incorporation of the intact metal dithiolene complex. Copolymerisation of 3 with thiophene gave a gold-coloured electropolymerised film of significant conductivity that, upon dissolution in CH2Cl2, showed the characteristic low energy absorption of the Ni-dithiolene complex, confirming its incorporation. This copolymerisation approach offers a versatile route to the synthesis of metal dithioleneâpolythiophene hybrid films.
描述了新的噻吩取代金属二硫代二乙烯配合物 [Ni(b-3ted)2] (3) 和 [NBu4][Ni(b-3ted)2] ([NBu4][3])的合成、电化学和光谱特性[b-3ted = 双(3-噻吩基)-1、2-ethylenedithiolene] ,并将其与对已知化合物 [Ni(b-2ted)2] (2) 和 [NBu4][Ni(b-2ted)2] ([NBu4][2]) 的新研究进行了比较。对中性复合物 2 和 3 的 X 射线结构进行了测定,结果表明,这两种复合物都显示出平面二硫环戊烯镍单元,其中的噻吩基团在分子平面外扭曲,从而排除了紧密的分子Ï-堆叠。电化学研究揭示了 3 与 2 类似的两个氧化还原过程,分别对应于中性、单阴离子和二阴离子物种之间的相互转化。0.1 mM [3]â 在 CH3CN 中的氧化反应显示出 3 的绿色分子膜,与制备的 3 晶体相比,该分子膜具有显著的导电性。在不同浓度下对 3 进行电化学聚合可生成薄膜;电化学、SNIFTIRS 和 UV-Vis 结果表明,这些薄膜中含有完整的金属二硫代二亚硝基络合物。与此相反,2 的电化学聚合产生了具有聚合噻吩特征的薄膜,但没有证据表明其中含有完整的二硫代二苯络合物。3 与噻吩共聚后产生了一层金色的电聚合薄膜,具有很强的导电性,在 CH2Cl2 中溶解后,显示出二硫代二苯镍络合物特有的低能量吸收,证实了它的加入。这种共聚方法为合成金属二硫环戊烯与聚噻吩的混合薄膜提供了一条多用途途径。