Gulcur Murat, Moreno-García Pavel, Zhao Xiaotao, Baghernejad Masoud, Batsanov Andrei S, Hong Wenjing, Bryce Martin R, Wandlowski Thomas
Department of Chemistry, Durham University, Durham DH1 3LE (UK).
Chemistry. 2014 Apr 14;20(16):4653-60. doi: 10.1002/chem.201304671. Epub 2014 Mar 5.
The synthesis and characterisation is described of six diaryltetrayne derivatives [Ar-(C≡C)4-Ar] with Ar=4-NO2-C6H4- (NO₂4), 4-NH(Me)C6H4- (NHMe4), 4-NMe2C6H4- (NMe₂4), 4-NH2-(2,6-dimethyl)C6H4- (DMeNH₂4), 5-indolyl (IN4) and 5-benzothienyl (BTh4). X-ray molecular structures are reported for NO₂4, NHMe4, DMeNH₂4, IN4 and BTh4. The stability of the tetraynes has been assessed under ambient laboratory conditions (20 °C, daylight and in air): NO₂4 and BTh4 are stable for at least six months without observable decomposition, whereas NHMe4, NMe₂4, DMeNH₂4 and IN4 decompose within a few hours or days. The derivative DMeNH₂4, with ortho-methyl groups partially shielding the tetrayne backbone, is considerably more stable than the parent compound with Ar=4-NH2C6H4 (NH₂4). The ability of the stable tetraynes to anchor in Au|molecule|Au junctions is reported. Scanning-tunnelling-microscopy break junction (STM-BJ) and mechanically controllable break junction (MCBJ) techniques are employed to investigate single-molecule conductance characteristics.
描述了六种二芳基四炔衍生物[Ar-(C≡C)4-Ar]的合成与表征，其中Ar = 4-NO2-C6H4-（NO₂4）、4-NH(Me)C6H4-（NHMe4）、4-NMe2C6H4-（NMe₂4）、4-NH2-(2,6-二甲基)C6H4-（DMeNH₂4）、5-吲哚基（IN4）和5-苯并噻吩基（BTh4）。报道了NO₂4、NHMe4、DMeNH₂4、IN4和BTh4的X射线分子结构。在实验室环境条件（20°C、日光和空气中）下评估了四炔的稳定性：NO₂4和BTh4至少六个月稳定，无明显分解，而NHMe4、NMe₂4、DMeNH₂4和IN4在数小时或数天内分解。具有邻位甲基部分屏蔽四炔主链的衍生物DMeNH₂4比Ar = 4-NH2C6H4（NH₂4）的母体化合物稳定得多。报道了稳定四炔在Au|分子|Au结中锚定的能力。采用扫描隧道显微镜断结（STM-BJ）和机械可控断结（MCBJ）技术研究单分子电导特性。
