Hexabenzocoronene

By using Hg-electrode-based junctions, the electrical properties of the highly conjugated units of hexa-pen-hexabenzocoronene (HBC) have been characterized [171]. The HBC unit was anchored to the Au metal surface in an Hg-based junction by a decanonanethiol tether (C19), as depicted in Fig. 9. Comparison of the electrical behaviour of three different junctions, whose interfaces are schematized... 

A more recent example of induction of chirality in a discotic using chiral side chains is hexabenzocoronene 45.46 In the solid state this large aromatic system exhibits a strong Cotton effect, indicating that in a similar mechanism to that of the phthalocyanines, a helical arrangement of the molecules occurs. 

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. 

Fig. 42 Effect of chain fluorination on the LC phases of peri-hexabenzocoronene based mesogens (compounds 152-155) [274—276] and the fused metalloporphyrin dimer 156 (7/° C) G = glassy state, Co/ortho = orthorhombic phase [277]...

The aromatic hydrocarbons 1,2-7,8-dibenzocoronene (79) and 1,12-2,3-4,5-6,7-8,9-10,11-hexabenzocoronene (80) have been studied, using partial three-dimensional data, by Robertson and Trotter (1961a, b) as part of a series of investigations into polynuclear aromatic hydrocarbons. The carbon skeletons of dibenzocoronene and hexabenzo-coronene are planar to within 0-038 and 0-065 A respectively. The r.m.s. deviations of the atoms from the appropriate mean molecular planes are 0-016 and 0-024 A, compared with the average estimated standard deviations in atomic position of 0-012 and 0-020 A respectively. There are, however, some indications from the electron density maps... 

Hill, J. P., Jin, W. S., Kosaka, A., et al., Self-assembled hexa-peri-hexabenzocoronene graphitic nanotube. Science 2004, 304, 1481-1483. 

Fig. 6. The contour maps of q3 of the two hexabenzocoronenes and kekulene showing the characteristic features of their Clar patterns...

Fechtenkoter, D., Saalwachter, A., Harbison, M.A., Mullen, K. and Spiess, H.W. (1999) Highly ordered columnar structures from hexa-peri-hexabenzocoronenes -synthesis,... 

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

Fukushima and Aida et al. reported that an achiral amphiphilic hexa-pen-hexabenzocoronene (HBC) 3 self-assembles into a helical coil and further into nanotubes in THF containing water (20% v/v) (Fig. 2) [37]. TEM revealed... 

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.]...

Piris J, Debije MG, Stutzmann N, Lairrsen BW, Pisula W, Watson MD, Bjornhohn T, Mullen K, Warman JM. (2004) Aligned thin films of discotic hexabenzocoronenes Anisotropy in the optical and charge transport properties. Adv Funct Mater 14 1053-1061. 

Warman JM, Piris J, Pisula W, Kastler M, Wasserlallen D, Mullen K. (2005) Charge recombination via intercoliunnar electron tunneling through the lipidlike mande of discotic hexa-alkyl-hexa-peri-hexabenzocoronenes./Hw Chem Soc 127 14257-14262. 

More recently, homologues of triphenylene with various size and perimeter types could be made by mild intramolecular dehydrogenation of suitable oligophenylene precursors. Thus, the transformation of hexaphenylbenzene 169 into hexabenzocoronene 170 occurs in quantitative fashion (see scheme 41) and non-hexagonal disc-type structures, such as C , C72 and ,2 are also available (see chart 27) [228]. The success of the unconventional synthesis and the loss of a large number of hydrogens can be monitored by LD-TOF mass spectrometry. 

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

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. 

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