Breakdown of interference rules in azulene, a nonalternant hydrocarbon.
Breakdown of interference rules in azulene, a nonalternant hydrocarbon.
复制标题
DOI：
10.1021/nl5010702
复制
发表时间：
2014-04
期刊：
影响因子：
10.8
通讯作者：
Jianlong Xia;B. Capozzi;Sujun Wei;M. Strange;A. Batra;J. Moreno;Roey J. Amir;E. Amir;G. Solomon;L. Venkataraman;L. Campos
中科院分区：
文献类型：
--
作者：
Jianlong Xia;B. Capozzi;Sujun Wei;M. Strange;A. Batra;J. Moreno;Roey J. Amir;E. Amir;G. Solomon;L. Venkataraman;L. Campos
我们设计并合成了五个在蔚蓝核内不同连接点含有金结合基团的蔚蓝衍生物，通过单分子电导测量来探索量子干涉的影响。我们比较了通过5元环、7元环和穿过蔚蓝的长轴的导电路径。我们发现，改变偶氮烯的连接点会影响光学性质(由UV-Vis吸收光谱确定)和导电性。重要的是，我们在这里表明，简单的模型不能用来预测非交替碳氢化合物的量子干涉特性。作为一个典型的例子，我们表明，根据广泛接受的原子计数模型预测的具有破坏性干涉的氮烯衍生物在低偏压下显示出显著的电导。虽然预测低偏压电导的简单模型并不适用于所有的天青烯衍生物，但我们证明了所有被研究的分子的测量电导趋势实际上与基于模型体系更完整的GW计算的预测一致。
We have designed and synthesized five azulene derivatives containing gold-binding groups at different points of connectivity within the azulene core to probe the effects of quantum interference through single-molecule conductance measurements. We compare conducting paths through the 5-membered ring, 7-membered ring, and across the long axis of azulene. We find that changing the points of connectivity in the azulene impacts the optical properties (as determined from UV-vis absorption spectra) and the conductivity. Importantly, we show here that simple models cannot be used to predict quantum interference characteristics of nonalternant hydrocarbons. As an exemplary case, we show that azulene derivatives that are predicted to exhibit destructive interference based on widely accepted atom-counting models show a significant conductance at low biases. Although simple models to predict the low-bias conductance do not hold with all azulene derivatives, we demonstrate that the measured conductance trend for all molecules studied actually agrees with predictions based on the more complete GW calculations for model systems.