Synthese partiell fluorierter Acene, DNTTs und Monomere für on-surface-Synthesen

In the context of this work, various partially fluorinated acenes could be prepared. Based on the synthesis of 1,2,10,11,12,14-hexafluoropentacene, a synthetic access to unilaterally functionalized pentacenes could be established, in which the central ring is built up step by step in complementary coupling reactions. This strategy could be successfully transferred to other acenes, such as 1,2,9,10,11-pentafluorotetracene and 1,2,12-trifluorotetracene. A novel synthesis of a pentacene with fluorine substituents in the 6,13 position based on successive FRIEDEL-CRAFTS acylations and an ortho-lithiation of 1,4-difluoroanthracene could also be realized. Then the optoelectronic properties and, in the case of 1,2,10,11,12,14-hexafluoropentacene and 1,2,9,10,11-pentafluorotetracene, also the solid-state structure of the new acenes were investigated in cooperation with the WITTE working group. Furthermore, partially fluorinated dinaphthothienothiophenes (DNTTs) could be synthesized in this work. Based on the synthesis of 1,2,3,4,8,9,10,11-octafluoronaphtho[2,3-b]naphtho[2',3':4,5]thieno[2,3-d]thiophene a new strategy for the regioselective introduction of the thiomethyl ether through an ortho-borylation / deborothiomethylation sequence was established. Based on this, 1,2,3,4-tetrafluoronaphtho[2,3-b]naphtho[2',3':4,5] thieno[2,3-d]thiophene could be prepared, in which the non-symmetrical substitution pattern could be realized by a WITTIG reaction. In the synthesis of 1,2,3,4-tetrafluoro-9,10-dimethoxynaphtho[2,3-b]naphtho[2',3':4,5]thieno[2,3-d]thiophene, the thio STILLE reaction can be described as a valid alternative for the introduction of the thiomethyl ether. Subsequently, the optoelectronic properties of the newly synthesized partially fluorinated DNTTs were investigated in collaboration with the WITTE working group and compared with derivatives known from the literature. In the field of ​​partially fluorinated monomers for on-surface syntheses, 4,4''-dibromo-2,2',2'',5,5',5''-hexafluoro-1,1':4',1''-terphenyl was successfully prepared in a two-step synthesis. This monomer was then vapor-deposited onto a gold surface in cooperation with the GOTTFRIED working group. There, depending on the temperature, a linear polymerization could first be initiated and then the resulting chains could be linked to two-dimensional carbon allotropes by HF zipping. It was observed that different structures develop, depending on whether the neighboring chains run parallely or antiparallely. When the chains were aligned antiparallel, a hexagonal graphene ribbon was created, while a new type of biphenylene ribbon with four, six, and eight rings was observed when the chains were aligned in parallel.