Fused Dibenzo[ a , m ]rubicene: A New Bowl-Shaped Subunit of C 70 Containing Two Pentagons
Total synthetic approaches of fullerenes are the holy grail for organic chemistry. So far, the main attempts have focused on the synthesis of the buckminsterfullerene C60. In contrast, access to subunits of the homologue C70 remains challenging. Here, we demonstrate an efficient bottom-up strategy toward a novel bowl-shaped polycyclic aromatic hydrocarbons (PAH) C34 with two pentagons. This PAH represents a subunit for C70 and of other higher fullerenes. The bowl-shaped structure was unambiguously determined by X-ray crystallography. A bowl-to-bowl inversion for a C70 fragment in solution was investigated by dynamic NMR analysis, showing a bowl-to-bowl inversion energy (ΔG(⧧)) of 16.7 kcal …
Polycyclic aromatic chains on metals and insulating layers by repetitive [3+2] cycloadditions
The vast potential of organic materials for electronic, optoelectronic and spintronic devices entails substantial interest in the fabrication of π-conjugated systems with tailored functionality directly at insulating interfaces. On-surface fabrication of such materials on non-metal surfaces remains to be demonstrated with high yield and selectivity. Here we present the synthesis of polyaromatic chains on metallic substrates, insulating layers, and in the solid state. Scanning probe microscopy shows the formation of azaullazine repeating units on Au(111), Ag(111), and h-BN/Cu(111), stemming from intermolecular homo-coupling via cycloaddition reactions of CN-substituted polycyclic aromatic az…
High-Performance Electron-Transporting Polymers Derived from a Heteroaryl Bis(trifluoroborate)
In this communication, we report that dipotassium aryl bis(trifluoroborate)s make stable and easy-to-purify yet reactive monomers under Suzuki polycondensation reactions. A bis(trifluoroborate) of 2-alkylbenzotriazole was prepared successfully and copolymerized with dibromobenzothiadiazole in the presence of a Pd catalyst and LiOH, yielding high molecular weight conjugated polymers. This polymer (P1) composed of all electron-accepting units shows excellent electron-transport properties (μ(e) = 0.02 cm(2) V(-1) s(-1)), which proves the value of the aryl bis(trifluoroborate) monomers and suggests that many other types of semiconducting polymers that could not be accessed previously can be syn…
Synthesis of Graphene Nanoribbons by Ambient-Pressure Chemical Vapor Deposition and Device Integration
Graphene nanoribbons (GNRs), quasi-one-dimensional graphene strips, have shown great potential for nanoscale electronics, optoelectronics, and photonics. Atomically precise GNRs can be "bottom-up" synthesized by surface-assisted assembly of molecular building blocks under ultra-high-vacuum conditions. However, large-scale and efficient synthesis of such GNRs at low cost remains a significant challenge. Here we report an efficient "bottom-up" chemical vapor deposition (CVD) process for inexpensive and high-throughput growth of structurally defined GNRs with varying structures under ambient-pressure conditions. The high quality of our CVD-grown GNRs is validated by a combination of different …
CCDC 1472204: Experimental Crystal Structure Determination
Related Article: Junzhi Liu, Silvio Osella, Ji Ma, Reinhard Berger, David Beljonne, Dieter Schollmeyer, Xinliang Feng, and Klaus Müllen|2016|J.Am.Chem.Soc.|138|8364|doi:10.1021/jacs.6b04426
CCDC 1521825: Experimental Crystal Structure Determination
Related Article: Zongping Chen, Wen Zhang, Carlos-Andres Palma, Alberto Lodi Rizzini, Bilu Liu, Ahmad Abbas, Nils Richter, Leonardo Martini, Xiao-Ye Wang, Nicola Cavani, Hao Lu, Neeraj Mishra, Camilla Coletti, Reinhard Berger, Florian Klappenberger, Mathias Kläui, Andrea Candini, Marco Affronte, Chongwu Zhou, Valentina De Renzi, Umberto del Pennino, Johannes V. Barth, Hans Joachim Räder, Akimitsu Narita, Xinliang Feng, and Klaus Müllen|2016|J.Am.Chem.Soc.|138|15488|doi:10.1021/jacs.6b10374
CCDC 1472205: Experimental Crystal Structure Determination
Related Article: Junzhi Liu, Silvio Osella, Ji Ma, Reinhard Berger, David Beljonne, Dieter Schollmeyer, Xinliang Feng, and Klaus Müllen|2016|J.Am.Chem.Soc.|138|8364|doi:10.1021/jacs.6b04426