Heterostructured Langmuir-Blodgett Films of Ruthenium Bipyridine with 1,3,4-Naphthooxadiazole-Derived Amphiphile Complex as a Charge Storage Electrode

The molecular control in Langmuir-Blodgett (LB) films may be exploited in charge storage electrodes provided a suitable choice of molecular architecture and components is made. In this paper, we employed a naphtyl-1,3,4-oxadiazole amphiphile (NFT1) and its complex [Ru(bpy)2NFT1]PF6 (RuNFT1) (bpy = 2,2’-bipyridine) in heterostructured LB films in a proof-of-principle production of charge storage. The optimized architecture contained a one-layer RuNFT1 deposited on a 9-layer NFT1 LB film, where the efficient packing of NFT1 inferred from spectroscopic measurements and Brewster angle microscopy (BAM) images was considered as relevant for ion diffusion. This packing was achieved owing to the π-stacking warranted by the planarity of the NFT1 naphtyl 1,3,4-oxadiazole ring, as confirmed with density functional theory (DFT) calculations. The top layer of the redox-active RuNFT1 provided an additional contribution with its Faradaic charge storage to the double layer capacitance of NFT1. Taken together, these results demonstrate that synergy may be achieved in combining distinct compounds in LB films toward efficient charge storage.朗缪尔-布洛杰特（Langmuir-Blodgett, LB）膜中的分子调控可应用于电荷存储电极，前提是需对分子结构与组分进行合理遴选。本文采用萘基-1,3,4-噁二唑两亲分子（NFT1）及其配合物[Ru(bpy)₂NFT1]PF₆（RuNFT1，其中bpy为2,2'-联吡啶）构建异质结构LB膜，开展电荷存储制备的原理验证研究。优化后的膜结构为：在9层NFT1 LB膜上沉积1层RuNFT1；其中，通过光谱测量与布鲁斯特角显微镜（BAM）图像证实的NFT1高效堆积，被认为对离子扩散具有关键作用。该堆积得益于NFT1萘基1,3,4-噁二唑环的平面性所保障的π-π堆叠，这一点通过密度泛函理论（DFT）计算得到验证。具有氧化还原活性的顶层RuNFT1，其法拉第电荷存储可为NFT1的双电层电容提供额外贡献。综上，本研究结果表明，在LB膜中结合不同组分可实现协同效应，从而获得高效的电荷存储性能。