扫描隧道显微镜（STM）能得到原子级别分辨率的图像，是观察单个分子、表面自组装、表面聚合反应产物的直观手段。同时结合扫描隧道谱（STS），STM可以检测单个分子的电学和磁学性质（例如分子的能级、自旋态、铁磁相互作用等）。STM已逐渐成为分子结构确定、理解精确反应机理和单分子操控的有效方法。基于该技术，我们的研究方向主要集中于：
（1）溶液合成超分子和聚合物的STM表征
由于二维金属配位超分子结构的平面特性和相对较大尺寸（5-50 nm），特别适合使用STM直接其精细结构。采用溶液滴涂、真空直接接触转移、制备级质谱软着陆等多种方法可适用不同的样品需求。
（2）表面可控合成低维超分子和聚合物
分子束外延技术为至下而上生长零维大环、一维和二维分子结构提供了新的途径。通过Ullmann和Glaser等偶联反应以及配位反应，在金属单晶表面上合成可控的原子级精确的新颖结构，同时通过引入其他弱相互作用力的模板作用对产物合成进行精准调控。精准结构加上多样的官能团引入，为进一步探索新颖的结构和功能奠定基础。
（3）表面超分子的可控组装与可控电磁性质调控
分子电子自旋材料有可能在单分子层面实现信息的存储和计算，可能得到具有颠覆性的计算和存储能力。把不同磁性官能团引入二维超分子，在表面能形成规则的自组装。通过STM针尖在磁性超分子各磁性中心上引入电场和磁场，实现对二维超分子单个磁性中心的逐一可逆调控和状态读取，即实现对信息的存储、读取和运算。为进一步构筑实用化的单分子信息存储和单分子量子器件奠定基础。
Scanning
Tunneling Microscopy (STM) can obtain atomic-level resolution images of
single molecules, surface self-assembly, and surface polymerization
reaction products. Combing with scanning tunneling spectroscopy (STS),
which can detect the electrical and magnetic properties of single
molecules (such as molecular energy levels, spin states, ferromagnetic
interactions, etc.), STM has become an effective method for molecular
structure determination, understanding of precise reaction mechanisms
and single-molecule manipulation. Based on this technology, our research
directions mainly focus on:
(1) STM characterization of supramolecules and polymers which are synthesized in solution
Due
to the plane feature and relatively large size (5-50 nm), the fine
structure of 2D metal-coordinated supramolecules are very suitable to be
detected by STM. Using the methods such as solution drop-casting,
vacuum direct contact transfer, and soft-landing through preparative
mass spectrometry, different sample requirements can be satisfied.
(2) On-surface synthesis of low-dimensional supramolecules and polymers
Molecular
beam epitaxy provides a new approach for bottom-up growth of
zero-dimensional macrocycles, 1D and 2D frameworks. Through Ullmann and
Glaser coupling reactions and coordination reactions, atomically precise
structures can be synthesized on the metal surface. Meanwhile, the
precision of product can be regulated through weak interactions such as
hydrogen and coordination bonds. The precise structure regulation and
various functional groups can further improve the explore of novel
structures and functions.
(3) Self-assembly and electronic and magnetic properties of supramolecules on surface
Molecular
spintronic materials may be applied for information storage and
computation at single-molecule level. Different magnetic functional
groups can be introduced into 2D supramolecules and then form regular
self-assembly on surface. After introducing electric field and magnetic
field, we can manipulate and read each magnetic center in the
supramolecule by STM tip, fulfilling the information writing and
reading. This kind of materials would be further used for
single-molecule information storage and quantum devices.