The self-assembly of a series hexadehydrotribenzo[12]annulene (DBA) derivatives has been scrutinized by scanning tunneling microscopy (STM) at the liquid−solid interface. First, influence core symmetry on network structure was investigated comparing two-dimensional (2D) ordering rhombic bisDBA 1a and triangular DBA 2a (Figure 1). BisDBA forms Kagomé upon physisorption from 1,2,4-trichlorobenzene (TCB) onto highly oriented pyrolytic graphite (HOPG). Under similar experimental conditions,...

New tool for surface modification: The 2D pattern formed by physisorbed dehydrobenzoannulene molecules on a graphite depends their concentration in solution. dependence is directly related to the difference stability between linear and honeycomb polymorphs respective molecular densities (see picture). Supporting information this article available WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z705322_s.pdf or from author. Please note: publisher not responsible content functionality...

We shine light on the covalent modification of graphite and graphene substrates using diazonium chemistry under ambient conditions. report nature chemical these graphitic substrates, relation between molecular structure film morphology, impact properties as revealed by local microscopy spectroscopy techniques electrochemistry. By careful selection reagents optimizing reaction conditions, a high density covalently grafted molecules is obtained, result that demonstrated in an unprecedented way...

Smaller can be better: The first example of meta-quinodimethane embedded in an indenofluorene framework has been synthesized. 10,12-Dimesitylindeno[2,1-b]fluorene exhibits extremely low-energy light absorption, despite the small conjugation space molecule, which consists only 20 π electrons.

A new isomer: 11,12-Dimesitylindeno[2,1-a]fluorene was synthesized and isolated in crystal form. The indenofluorene exhibits significant bond-length alternation the o-quinodimethane structure, limited singlet biradical character, weakly antiaromatic character. Optical electrochemical properties suggest that indeno[2,1-a]fluorene derivatives may be candidates for optoelectronic materials. Detailed facts of importance to specialist readers are published as "Supporting Information". Such...

m-Diethynylbenzene macrocycles (DBMs), buta-1,3-diyne-bridged [4(n)]metacyclophanes, have been synthesized and their self-association behaviors in solution were investigated. Cyclic tetramers, hexamers, octamers of DBMs having exo-annular octyl, hexadecyl, 3,6,9-trioxadecyl ester groups prepared by intermolecular oxidative coupling dimer units or intramolecular cyclization the corresponding open-chain oligomers. The aggregation properties investigated two methods, (1)H NMR spectra vapor...

Making honeycomb: The addition of guest molecules to a linear nonporous two-dimensional network results in its transformation into honeycomb porous network. shows selectivity (see picture). Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z604782_s.pdf or from author. Please note: publisher not responsible content functionality any supporting supplied by authors. Any queries (other than missing content) should be directed...

Two-dimensional (2D) supramolecular self-assembly at liquid-solid interfaces is a thermodynamically complex process producing variety of structures. The formation multiple network morphologies from the same molecular building blocks common occurrence. We use scanning tunnelling microscopy (STM) to investigate structural phase transition between densely packed and porous an alkylated dehydrobenzo[12]annulene (DBA) derivative physisorbed solvent-graphite interface. influence temperature...

At the liquid/graphite interface triangular and rhombic phenylene–ethynylene macrocycles substituted by alkyl chains self-assemble to form porous two-dimensional (2D) molecular networks of honeycomb Kagomé types, respectively, or close-packed non-porous structures via chain interdigitation as directional intermolecular linkages. Factors that affect formation 2D networks, such length, solvent, solute concentration, co-adsorption guest molecules, were elucidated through a systematic study. For...

Get it together: A four-component 2D crystal has been formed at a liquid–solid interface and successfully visualized by scanning tunneling microscopy. Simply premixing the four components applying solution onto graphite surface leads to spontaneous self-assembly of crystal. Selected guest molecules induce structural transformation host network from nonporous porous coadsorption inside pores. Detailed facts importance specialist readers are published as "Supporting Information". Such...

The self-assembly of a series hexadehydrotribenzo[12]annulene (DBA) derivatives has been investigated by scanning tunneling microscopy (STM) at the liquid/solid interface in absence and presence nanographene guests. In appropriate guest molecules, DBA with short alkoxy chains form two-dimensional (2D) porous honeycomb type patterns, whereas those long predominantly dense-packed linear patterns. Added molecules adsorb pores existing 2D patterns or, more interestingly, they even convert...

Recognition and selection are of fundamental importance for the hierarchical assembly supramolecular systems. Coronene induces formation a hydrogen-bonded isophthalic acid macrocycle, this well-defined heterocluster forces, in its turn, DBA1 to form van der Waals stabilized honeycomb lattice, leading three-component 2D crystal containing nine molecules unit cell. The recognition events enable efficient error correction healing redundant mixtures.

The development of the chemistry non-alternant non-benzenoid hydrocarbons is reviewed in connection with International Symposium on Novel Aromatic Compounds (ISNA) and author's personal anecdotes. Past molecules include classics this class compounds, pentalene, azulene, heptalene, structurally integrated congeners such as indacenes formed by benzannelation benzinterposition, which were extensively studied during last century. Indenofluorene isomers constructed to represent present molecules,...

A tetramesityl derivative of hitherto unknown tetracyclopenta[def,jkl,pqr,vwx]tetraphenylene (TCPTP), which is a potential tetraradicaloid hydrocarbon, was synthesized. Theoretical calculations based on spin-flip time-dependent density functional theory predict that the closed-shell D2h form TCPTP more stable than open-shell D4h with its slightly tetraradical character. The (Mes)4 -TCPTP exhibits remarkable antiaromaticity as result peripheral 20-π-electron circuit, causes an absorption...

We present here the formation of a molecular Kagomé network within two-dimensional (2D) crystal on surface. This system provides clear example how, by design, geometry can be expressed at level 2D lattice, leading to open networks. Key elements control are core symmetry, location and orientation interacting connecting substituents, as well symmetry matching between networks

A series of alkyl- and alkoxy-substituted rhombic-shaped bisDBA derivatives 1a−d, 2a, 2b were synthesized for the purpose formation porous networks at 1,2,4-trichlorobenzene (TCB)/graphite interface. Depending on alkyl-chain length solute concentration, bisDBAs exhibit five network structures, three structures (porous A, B, C), two nonporous (nonporous D E), which are attributed to their rhombic core shape position substituents. BisDBAs 1a 1b with shorter alkyl chains favorably form a...

[reaction: see text] Trefoil-shaped tris(hexadehydrotribenzo[12]annulene) possessing a substructure of the ultimate two-dimensional C(sp)-C(sp(2)) network, graphyne, and related tris(tetradehydrotribenzo[12]annulene) were synthesized, their ground- excited-state properties investigated.

Zethrenes were synthesized by Pd-catalyzed cyclodimerization of 1-ethynyl-8-iodonaphthalenes. The structure these cycloadducts was confirmed X-ray crystal analysis. bond lengths and alternation in the structures reveal that central two six-membered rings title compounds lack aromaticity.

Kleiner Lichtabsorber: Das erste Beispiel eines meta-Chinodimethans als Bestandteil Indenofluoren-Gerüsts wurde synthetisiert. 10,12-Dimesitylindeno[2,1-b]fluoren zeigt eine extrem niederenergetische Absorption, trotz des kleinen konjugierten Systems Moleküls, das nur 20 π-Elektronen aufweist. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed may be re-organized for online delivery, but not...

Synthesis of 13,14-dimesitylbenz[c]indeno[2,1-a]fluorene (9b), a 2,3-naphthoquinodimethane derivative isolated for the first time, was achieved. The X-ray crystallographic structure and spectroscopic electrochemical properties 9b indicate substantial singlet biradical character which is higher than that 11,12-dimesitylindeno[2,1-a]fluorene (8b), in accord with quantum chemical study. Cycloadditions oxygen dichlorodicyano-p-benzoquinone took place at inner naphthalene carbons rather most...