基于主族元素类过渡金属特性的材料设计与模拟

Carbon nanomaterials (CNMs) consist of carbon atoms that are condensely packed through strong covalent bonds. The preparation of CNMs needs to be achieved in harsh reaction conditions, e.g., at high temperatures; therefore, the material structures are not controllable during preparation. Metal-organic framework (MOF) and covalent-organic framework materials can be prepared in mild conditions. However, because of their highly localized chemical bonding, these materials are usually electric insulators or wide-bandgap semiconductors, and cannot be used as transistors. The design of metals and small-bandgap semiconductors that can be synthesized in mild conditions and in a structurally controllable manner is a challenge. Reportedly, main group elements can form σ-donation and π-back donation bonds with ligands like CO, showing transition-metal like electronic configuration and bonding ability. This property of main group elements have attracted much interest. However, little effort has been made to design new materials based on this properties of main-group elements. We have recently reported the design of metal and semiconductor materials based on main-group elements; interestingly, these materials may be experimentally synthesized at a low temperature and in a structurally controllable manner. In this project, we will use first principle calculations to systematically study the mechanisms of formation for the transition-metal like compounds of group 2, 13, 14, and 15 elements, and design and compute zero-, one-, and two-dimensional materials based on these main-group elements. We will also study the “face-to-face” addition of two-dimensional materials that consist of triple bonds, through which we will design the corresponding three-dimensional materials. The results will promisingly integrate the new findings of main-group chemistry into material science, and guide the low-temperature and structurally-controllable synthesis of metals and semiconductor materials.

碳纳米材料由碳原子以较强共价键密堆积形成，制备需要高温，难以控制材料结构。金属有机和共价有机框架材料能在较温和条件下合成，然而其化学键有强定域性，材料多为绝缘体或宽带隙半导体，难以用作晶体管器件。设计低温、结构可控制备的金属或窄带隙半导体材料是个挑战。近年研究发现，主族元素可和CO等配体形成配位σ键和反馈π键，表现“类过渡金属”电子组态和成键行为，引发了人们极大关注。然而利用主族元素这一特性进行材料设计鲜有报道。我们前期研究表明，可基于主族元素该特性设计有望低温、结构可控制备的金属和半导体材料。本项目将用第一性原理方法系统研究第2、13、14、15族元素形成“类过渡金属”化合物的机理，设计和模拟零维、一维和二维新材料；研究含三键二维主族材料的“面对面”加成反应，设计相应三维材料。研究结果有望将主族化学的新成果应用到材料领域，为低温、结构可控的金属和半导体材料制备提供理论指导。

近年研究发现，主族元素B可和CO等配体形成配位σ键和反馈π键，表现“类过渡金属”电子组态和成键行为，引发了人们极大关注。然而利用主族元素这一特性进行材料设计鲜有报道。本项目用第一性原理方法探明了主族元素形成“类过渡金属”化合物的机理。设计和模拟了零维、一维和二维新材料，并利用“面对面”加成反应，设计了相应三维材料。此外，探索了上述材料、金属基纳米材料及其杂化结构用于生物体内活性氧调控的可能性，系统地研究了构效关系，提出了活性氧调控活性描述符，形成了自己的特色。.本项目共取得三项重要成果。.首先，在分子水平阐明了第2，13，14和15主族元素实验中已经合成的“类过渡金属”化合物的生成机理。该类主族元素表现出“类过渡金属”性质的根本原因是该类元素具有缺电子特性，因而具有多种成键方式。这种碱稳定的硼烯和硼基为设计和合成新的硼分子提供了广阔的机会。.其次，设计和模拟了零维、一维和二维新材料，并利用“面对面”加成反应，设计了相应三维材料。设计低温、结构可控制备的金属或窄带隙半导体材料是个挑战。本项目利用主族元素“类过渡金属”性质，设计了基于B、N、P元素的零维、一维和二维新材料并评估了其稳定性。电子结构研究结果表明，一维类茂金属材料是好的自选半导体器件，B，N共掺杂石墨炔是难得的窄带半导体材料，而电子对互斥效应致使黑磷产生奇特的边缘效应。.最后，率先使用第一性原理计算方法在分子水平研究纳米材料模拟生物酶催化的微观机理、催化反应动力学、构效关系和理论模型，在纳米材料仿酶催化基础研究方面取得了一系列原创性研究成果，并和多个实验课题组深入合作，推动纳米材料仿生催化应用研究进展。.研究结果有望将主族化学的新成果应用到医用纳米材料领域，为低温、结构可控的基于主族元素的纳米材料的制备提供理论指导。.