Hexabenzocoronene derivatives

A mono- and a bis-tricarbonylchromium complex of a hexabenzocoronene derivative substituted with... 

Andrienko D., Marcon V. and Kremer K. (2006), Atomistic simulation of structure and dynamics of columnar phases of hexabenzocoronene derivatives , J. Chem. Phys. 125, 124902-1-124902-8. 

In general, for side chain liquid-crystalline polymers, macroscopic molecular alignment is not easy and therefore clear evidence of electronic charge carrier transport was confirmed first in liquid crystals with low molecular weight. In the 1990s, fast electronic conduction was verified in discotic columnar phases of triphenylene derivatives [79,80] and hexabenzocoronene derivatives [81,82] as well as smectic phases of 2-phenylbenzothiazole [83, 84] and 2-phenylnaphthalene derivatives [85], as shown in Fig. 14. Carrier... 

The calculation of NMR chemical shifts at the uncorrelated HF-SCF level is nowadays routinely possible using CPHF theory. Efficient implementations have been reported in particular within the GIAO approach [35,91] and (using integral-direct techniques) calculations on large molecules consisting of more than 100 atoms are routinely possible [91]. Recent examples include HF-SCF calculations on hexabenzocoronene derivatives [24,25] as well on aluminum halide clusters [18]. The status here has been earlier reviewed by others and thus will not be repeated. Our focus will be instead on electron-correlated approaches, in particular, as consideration of electron-correlation effects is essential in many cases. 

A new class of hexabenzocoronene derivatives, e.g. compounds (Scheme 7.13) can self-organize into liquid crystalline phases composed of molecular stacks that orient spontaneously parallel to the surface [177, 178]. Field effect transistors based on these materials show high charge-carrier mobilities, high on/off ratios, and low tum-on voltages. So far compound 44 exhibits the best field effect transistor properties achieved for a columnar discotic material. Polarized fight microscopy revealed that these materials tend to orient their columns parallel to the surface upon thermal annealing. 

Bunk, O. Nielsen, M. M. Soiling, T. L van de Craats, A. M. Stutzmann, N. Induced alignment of a solution-cast discotic hexabenzocoronene derivative for electronic devices investigated by surface X-ray diffraction. J. Am. Chem. Soc. 2003,125, 2252-2258. 

C. Ochsenfeld, S.P. Brown, I. SchneU,J. Gauss, H.W. Spiess, Strucmre assignment in the solid state by the coupling of qimnmm chemical calculations with NMR experiments a columnar hexabenzocoronene derivative, J. Am. Chem. Soc. 123 (2001) 2597-2606. 

Diels-Alder reaction of tetraarylcyclopentadienone with diarylacetylene with concomitant elimination of carbon monoxide results in the formation of hexaaryl-substituted benzene [42]. The hexaarylbenzenes serve as precursors for the synthesis of hexabenzocoronene derivatives (Scheme 16.39) [43], The Diels-Alder step generally gives excellent yields of the hexaarylbenzenes. 

Figure 18 AFM image of (a) a pure hexabenzocoronene derivative fiim, (b) a pure perylene di-imide film, and (c) a spin-coated fiim from a biend soiution of hexabenzocoronene and perylene derivatives. Reprinted figures with permission from L. Schmidt-Mende, A. Fechtenkotter, K. Mullen, E. Moons, R.H. Friend, and J.D. McKenzie, Sc/ ence 293, 1119(2001), Figure2and3. Copyright 2001 AAAS.

Relation between NMR Chemical Shifts and Solid-State Structures Hexabenzocoronene Derivatives. 

Structure Assignment in the Solid State by the Coupling of Quantum Chemical Calculations with NMR Experiments A Columnar Hexabenzocoronene Derivative. 

C150H186 hexabenzocoronene derivative polymantanes acenaphthofluoranthenes c/s-polyisoprene -[CH2C(CH3)=CHCH2].-isoprene—isobutylene copolymer styrene—butadiene copolymer ethylene—propylene copolymer liquid crystal (component for photovoltaic films) new material hydrocarbons built from fused adamantine units conductive ladder polymer natural rubber synthetic rubber... 

Zilberman Y, Tisch U et al (2009) Spongelike Structures of hexa-peri-hexabenzocoronene derivatives enhance the sensitivity of chemiresistive carbon nanotubes to nonpolar volatile organic compounds of cancer. Langmuir 25(9) 5411-5416... 

PAH chemistry is of practical as well as theoretical interest. PAHs can be regarded as well defined subunits of graphite, an important industrial material, which is so far not totally understood at the macroscopic level. In this context, it is our aim to delineate the molecular size at which the electronic properties of PAHs converge to those of graphite. Furthermore, alkyl substituted derivatives of hexabenzocoronene (HBC) form discotic mesophases and, therefore, provide opportunities for materials which allow one-dimensional transport processes along their columnar axis [83,84]. Their application for photovoltaics and Xerox processes is also of current interest. 

Finally, high-resolution XH NMR techniques employing fast MAS have been used to study the structure and dynamics of a hexabenzocoronene carboxylic acid derivative [25] shown below. 

Next to the phthalocyanines, the group of compounds most studied in recent years has been hexa-alkyl derivatives of hexa- m-hexabenzocoronene ( HBC or Ar42 in Fig. The results... 

Fig. 7. The temporal dependence of the conductivity decay, normalized to the end-of-pulse value, on 5 ns pulsed ionization of hexa-alkyl derivatives of hexa- m -hexabenzocoronene (HBC) with ethyl-hexyl (C6,2), hexyl-decyl (C10,6), and decyl-tetradecyl (C14,10) branched alkyl chains illustrating the dramatic increase in lifetime of the charge carriers with increasing length of the peripheral chains. [Reprinted WPh permission from Ref. 98. Copyright 2005 American Chemical Society.]...

Consider the hexabenzocoronene (HBC) derivative, 2, 5, 8, 11, 14, 17-hexa[ 10-carboxydecyl]hexa-/ /7-hexabenzocoronene, 6, (henceforth referred to as... 

Disc-shaped aromatic hexabenzocoronene (HBC) derivatives (6a-6d) (Figure... 

Similar results may be expected if larger coronenes are deposited, which have a similar structure to graphene layers, e.g. hexaphenylbenzene, hexa-pen-hexabenzocoronene, and derivatives on Cu(l 11) [67]. 

Fig. 28 Top chemical structure of the hexabenzocoronene (HBC) derivative with six anthraquinone groups (PAH-ANT) and 9,10-dimethoxyanthracene (DMA). Bottom schematic of the prototypical single-molecule field-effect transistor. High resolution STM image of a monolayer formed from a mixed solution of the HBC-anthraqmnone molecule and DMA. The DMA molecules, indicated by small white dots, are adsorbed on top of the anthraquinone molecules and form a charge-transfer complex. (Reproduced with permission from [85])...

The addition of organometallic compounds to benzoquinone derivatives was an early approach for the synthesis of PAHs. The diol obtained was subsequently aromatized and cyclodehydrogenated to give the PAH [19-22]. An example of such an approach is depicted in Scheme 3. Clar et al. synthesized a cata-hexabenzocoronene 9 by this method. 

The orthogonal formation of self-assembled polymers is a convenient way to prepare nanosized p- and n-type fibers that coexist in a single system while starting from a mixed solution of electron donor and acceptor building blocks, respectively. An elegant example reported by Mullen et al. shows the ability to prepare a doublelayered heterojunction by processing a chloroform solution of a hexaphenyl-substituted hexabenzocoronene (HBC) and a perylene bisimide (FBI) derivative. The phase separation between the two systems is a direct consequence of... 

Figure 5 The general structures of hexa-pen-hexabenzocoronene (HBC) 8 and its functionalized derivatives 9. Reactive monomo-10 that assanbles into a cross-linkable LC columnar phase.

M. Randic, D. Vukicevic, A. T. Balaban, M. Vracko, and D. Plavsic, Conjugated circuits currents in hexabenzocoronene and its derivatives formed by joining proximal carbons, J. Comput. Chem. 33 (2012) 1111-1122. 

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