Zong Wansheng, Hippchen Nikolai, Zeitter Nico, Maier Steffen, Ludwig Philipp, Rominger Frank, Freudenberg Jan, Bunz Uwe H F
Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
J Am Chem Soc. 2024 Mar 6;146(9):5793-5798. doi: 10.1021/jacs.3c13629. Epub 2024 Feb 27.
The symmetrical 7,16-diaza-6,8,15,17-tetrakis(triisopropylsilylethynyl)heptacene was obtained by a Pd-catalyzed reaction of a 2,3-diamino-1,4-diethynylanthracene with a 2,3-dibromo-1,4-diethynyl anthracene. Positioning the TIPS-ethynyl groups adjacent to the central ring suppresses dimerization via [4+4] cycloadditions and Diels-Alder reactions; the middle pyrazine ring renders this species stable to oxidation. A single crystal structure was obtained, and thin film transistors with μ = 0.042 cm V s were produced. Transposition of the alkynyl groups into the 5,8,15,18-positions with a quinoxaline unit in the center of the heptacene decreases the stability, as does the introduction of two more nitrogen atoms into the 5,18-positions. The hydrocarbon 6,8,15,17-tetrakis(triisopropylsilylethynyl)heptacene is reasonably stable with a half-life of 25 h in solution. Four correctly placed TIPS-ethynyl groups protect heptacene cores.
对称的7,16-二氮杂-6,8,15,17-四（三异丙基甲硅烷基乙炔基）并七苯是通过2,3-二氨基-1,4-二乙炔基蒽与2,3-二溴-1,4-二乙炔基蒽的钯催化反应得到的。将三异丙基甲硅烷基乙炔基（TIPS-乙炔基）基团置于中心环附近可抑制通过[4+4]环加成和狄尔斯-阿尔德反应的二聚化；中间的吡嗪环使该物种对氧化稳定。获得了单晶结构，并制备了迁移率μ = 0.042 cm² V⁻¹ s⁻¹的薄膜晶体管。将炔基转移到并七苯中心带有喹喔啉单元的5,8,15,18位会降低稳定性，在5,18位引入另外两个氮原子也会降低稳定性。烃类6,8,15,17-四（三异丙基甲硅烷基乙炔基）并七苯在溶液中的半衰期为25小时，具有相当的稳定性。四个正确定位的TIPS-乙炔基基团保护并七苯核心。
