Solid State Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Staudtstr. 7, 91058 Erlangen, Germany.
ACS Nano. 2018 Feb 27;12(2):1203-1210. doi: 10.1021/acsnano.7b06998. Epub 2018 Jan 22.
We studied the formation of linked porphyrin oligomers from 5,15-diphenylporphyrin (2H-DPP) by thermal, substrate-assisted organometallic and dehydrogenation coupling on Cu(111) by scanning tunneling microscopy. In the range of 300-620 K, we find three distinct stages, at 300 K, the intact 2H-DPP molecules self-assemble into linear structures held together by van der Waals forces. Increasing the substrate temperature, self-metalation and intramolecular ring-closing reactions result in planar and isolated DPP species on the surface. By C-H cleavage, porphyrin oligomers bonded by organometallic and covalent bonds between the modified DPP are formed. The amount of covalently bonded DPP oligomers increases strongly with annealing time and temperature, and they become the dominant species at 570 K. In contrast, the number of organometallically bonded DPP oligomers increases moderately even up to 620 K, indicating that in this case the organometallic bond is no precursor of the covalent bond.
我们通过扫描隧道显微镜研究了 5,15-二苯基卟啉（2H-DPP）在 Cu(111)表面上通过热、基底辅助的有机金属和脱氢偶联形成连接的卟啉寡聚物。在 300-620 K 的范围内，我们发现了三个不同的阶段，在 300 K 时，完整的 2H-DPP 分子通过范德华力自组装成线性结构。随着温度的升高，自金属化和分子内环化反应导致表面上形成平面且孤立的 DPP 物种。通过 C-H 断裂，通过有机金属和修饰的 DPP 之间的共价键键合的卟啉寡聚物形成。共价键合的 DPP 寡聚物的数量随着退火时间和温度的增加而强烈增加，并且它们在 570 K 时成为主要物种。相比之下，即使在 620 K 时，有机金属键合的 DPP 寡聚物的数量也适度增加，表明在这种情况下，有机金属键不是共价键的前体。
