Department of Chemistry, Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, Xiangtan University, Hunan Province 411105, P. R. China.
Nanoscale. 2015 Aug 28;7(32):13734-46. doi: 10.1039/c5nr02608c. Epub 2015 Jul 29.
The electronic and magnetic properties of transition metal (TM = Sc, Ti, V, Cr and Mn) atom incorporated single and double one-dimensional (1D) styrene molecular wires confined on the hydrogen-terminated Si(100) surface are explored for the first time by means of spin-polarized density functional theory, denoted as Si-[TM(styrene)]. It is unveiled that TM atoms bind asymmetrically to the adjacent phenyl rings, which leads to novel electronic and magnetic properties in stark contrast to the well-studied gas phase TM-benzene molecular wires. Si-[Mn(styrene)]∞ and Si-[Cr(styrene)]∞ single molecular wires (SMWs) are a ferromagnetic semiconductor and half metal, respectively. Creation of H-atom defects on the silicon surface can introduce an impurity metallic band, which leads to novel half-metallic magnetism of a Si-[Mn(styrene)]∞ system. Moreover, double molecular wires (DMWs) containing two identical or hetero SMWs are theoretically designed. The [Mn(styrene)]∞-[Cr(styrene)]∞ DMW exhibits half-metallic magnetism where the spin-up and spin-down channels are contributed by two single molecular wires. Finally, we demonstrate that introducing a TM-defect may significantly affect the electronic structure and magnetic properties of molecular wires. These studies provide new insights into the structure and properties of surface supported 1-D sandwiched molecular wires and may inspire the future experimental synthesis of substrate confined organometallic sandwiched molecular wires.
首次通过自旋极化密度泛函理论研究了过渡金属（TM = Sc、Ti、V、Cr 和 Mn）原子掺入单和双一维（1D）苯乙烯分子线在氢终止硅（100）表面上的电子和磁性质，记为 Si-[TM（苯乙烯）]。研究揭示 TM 原子不对称地结合到相邻的苯基环上，导致与研究充分的气相 TM-苯分子线相比具有新颖的电子和磁性质。Si-[Mn（苯乙烯）]∞和 Si-[Cr（苯乙烯）]∞单分子线（SMW）分别是铁磁半导体和半金属。在硅表面上创建 H 原子缺陷可以引入杂质金属带，从而导致 Si-[Mn（苯乙烯）]∞系统的新型半金属磁性。此外，还理论设计了包含两个相同或杂 SMW 的双分子线（DMW）。[Mn（苯乙烯）]∞-[Cr（苯乙烯）]∞ DMW 表现出半金属磁性，其中自旋向上和自旋向下通道由两个单分子线贡献。最后，我们证明了引入 TM 缺陷可能会显著影响分子线的电子结构和磁性质。这些研究为表面支持的 1D 夹心分子线的结构和性质提供了新的见解，并可能激发未来对基底限制的有机金属夹心分子线的实验合成。
