Molecular domino toppling for directed self-erasing information transfer

In the pursuit of more secure information transfer, advanced nanoelectronic technologies and nanomaterials must be developed. Here, we present a material able to undergo an unprecedented light-pumped directional charge transfer process reminiscent of toppling dominoes. The material is based on ortho-fluorinated azobenzene molecules which are organized in molecular rows by the regular array of a metal-organic framework. The azobenzene molecules undergo light-induced transcis forward as well as electrocatalytic cistrans backward isomerization. Our findings reveal that electron hopping occurs in a sequential and propagating manner between the light-generated cis isomers along with an isomerization of the sample to the trans state. Thus, light can be used to locally write information, which subsequently can be read out by the transferred charge with simultaneous deletion of the information. This freely repeatable, self-erasing domino information transfer is a groundbreaking new mechanism to process information on the molecular level that may find application in encryption.

为实现更安全的信息传输，亟需开发先进的纳米电子技术与纳米材料。本研究报道了一种可实现前所未有的光泵浦定向电荷转移过程的材料，其过程恰似倾倒的多米诺骨牌一般。该材料以邻氟偶氮苯分子（ortho-fluorinated azobenzene molecules）为基础，这类分子通过金属有机框架（metal-organic framework）的规则阵列排列成分子链。此类偶氮苯分子可发生光诱导反式→顺式正向异构化，以及电催化顺式→反式逆向异构化。本研究结果表明，电子跳跃（electron hopping）以序列式且可传播的方式发生在光诱导生成的顺式异构体之间，同时样品整体发生异构化转变为反式状态。因此，可利用光在局部写入信息，后续可通过转移的电荷读取该信息，同时完成信息的擦除。这种可自由重复、自擦除的多米诺式信息传输机制，是一种可在分子层面处理信息的突破性全新机制，有望应用于加密领域。