Surface-Based Self-Assembly of 3-D Spintronic Coordination Nano-Architectures

在COORNETs的框架内，我们的目标是在超高真空条件下，通过升华和/或电喷雾电离(ESI)积层，在定义明确的界面上构建强大的三维自旋电子配位网络。三维自组装过程利用定制设计的分子连接体和磁性活性金属中心之间的金属-配体相互作用来提供功能纳米结构。值得注意的是，我们计划设计提供不同磁性特征的模板配位网络，包括(I)基于Fe(II)的自旋交叉(SCO)或(Ii)带有磁性过渡金属或稀土元素官能化的四吡咯分子。此外，电导率的提高将通过(I)将可光聚合的部分包含在MOF构建块中或(Ii)设计配位节点来探索。所获得的表面三维网络的物理化学性质和功能行为将通过分子水平扫描隧道显微镜/光谱观测(STM/STS)进行研究，并辅之以高分辨率X射线光谱、X射线磁性圆二色谱(XMCD)和一系列补充的复杂方法。意见：我们的合作依赖于在分子配位和表面共价网络或纳米结构的自组装和表征方面的长期专业知识(在过去几年中有35多份联合出版物)。在此，我们尤其对自旋电子材料和器件感兴趣，包括它们的结构、电子、磁性或机械性能。相关的熟练程度依赖于精心定制和从头合成分子砖的概念，以及在近地表条件下指导过程和空间组织的组装方案的开发。表面网络和纳米结构的结构、电学和磁学表征主要通过STM/STS和X射线光谱技术相结合来实现。提供的成果：我们计划获得具有独特功能性质的新型自旋电子配位网络，特别是(I)基于自旋交叉化合物和卟啉/酞菁结合的可切换磁性，以及(Ii)通过设计配位节点或连接体物种的官能化来实现后合成光聚合的自旋电子导电性。

Within the frame of COORNETs we aim at the construction of robust 3-D spintronic coordination networks at well-defined interfaces under ultra-high vacuum conditions using sublimation and/or electrospray ionization (ESI) deposition of building blocks. The 3-D self-assembly process exploits metal-ligand interactions between custom-designed molecular linkers and magnetically active metal centers to afford functional nano-architectures. We notably plan to engineer templated coordination networks providing different magnetic features, incorporating (i) Fe(II) based spin-crossover (SCO) or (ii) tetrapyrrole molecules functionalized with magnetic transition metals or lanthanides. Moreover, enhancement of electric conductivity will be explored by (i) inclusion of photopolymerizable moieties in the MOF building block or (ii) engineering of the coordination node. The physicochemical properties and functional behaviour of the obtained surface-based 3-D networks will be studied by molecular-level scanning tunneling microscopy/spectroscopy observations (STM/STS), complemented by high-resolution X-ray spectroscopies, X-ray magnetic circular dichroism (XMCD), and a set of complementary sophisticated methods. Input: Our collaboration relies on a longstanding expertise in the self-assembly and the characterization of molecule-based coordination and covalent networks or nanostructures on surfaces (with more than 35 joint publications during the last years). In particular, we are herein interested in spintronic materials and devices, including their structural, electronic, magnetic or mechanical properties. The relevant proficiency relies on the conception of carefully tailored and de-novo synthesized molecular bricks, as well on the development of assembly protocols to steer processes and spatial organization under near-surface conditions. The structural, electrical and magnetic characterization of the obtained surface-based networks and nano-architectures is achieved mainly by a combination of STM/STS and X-ray spectroscopy techniques. Output offered: We plan to obtain new classes of spintronic coordination networks with unique functional properties, in particular (i) switchable magnetic properties based on spin crossover compounds and porphyrins/phthalocyanines combined with (ii) spintronic conductivity through engineering of either the coordination node or the functionalizing of linker species for post-synthetic photopolymerization.