[5]Helicene-Fused Phthalocyanine Derivatives. New Members of the Phthalocyanine Family

Sooksimuang, Thanasat; Mandal, Braja K.

doi:10.1021/jo026413v

Cited by 41 publications

(20 citation statements)

References 31 publications

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“…The optical and electronic properties of MPcs strongly depend on the size of the π‐system . The expansion of the phthalocyanine π‐system has been achieved by condensation of fused polyaromatic precursors . The size and geometry of the annulated aromatic residues on the tetraazaporphyrin core affects the position of the Q band, as well as the HOMO and LUMO energy levels.…”

Section: Introductionmentioning

confidence: 99%

Topological Control of Columnar Stacking Made of Liquid‐Crystalline Thiophene‐Fused Metallonaphthalocyanines

et al. 2015

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The spontaneous organization of two‐dimensional polyaromatic molecules into well‐defined nanostructures through noncovalent interactions is important in the development of organic‐based electronic and optoelectronic devices. Two regioisomers of thiophene‐fused zinc naphthalocyanines ZnTNcendo and ZnTNcexo have been designed and synthesized to obtain photo‐ and electroactive liquid crystalline materials. Both compounds exhibited liquid crystalline behavior over a wide temperature range through intermolecular π–π interactions and local phase segregation between the aromatic cores and peripheral side chains. The structural differences between ZnTNcendo and ZnTNcexo affected the stacking mode in self‐assembled columns, as well as symmetry of the two‐dimensional rectangular columnar lattice. The columnar structure in liquid crystalline phase exhibited an ambipolar charge‐transport behavior.

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Section: Introductionmentioning

confidence: 99%

Topological Control of Columnar Stacking Made of Liquid‐Crystalline Thiophene‐Fused Metallonaphthalocyanines

et al. 2015

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“…[10] The synthesis of phthalocyanines with extended p-systems (Scheme 1) is commonly achieved by using an ortho-dicyano precursor for the cyclotetramerization reaction to the Pc. Owing to a lack of methods for the direct ortho-functionalization of polycyclic aromatic hydrocarbons (PAH), precursors were built from various benzene or naphthalene derivatives for the synthesis of phenanthralocyanine (Phc), [11] triphenylenophthalocyanine (Tc), [12] helicenocyanine (Hc), [13] benzohelicenocyanine (BHc), [14] and perylenophthalocyanine (PPc). [15] Synthetic routes to multiply benzannulated Pcs have been designed to include solubilizing alkyl chains to overcome solubility problems.…”

Section: Introductionmentioning

confidence: 99%

4,5‐Pyrenocyanine—Just Another Phthalocyanine? A STM and 2D WAXS Study

Zöphel

Mali

Puniredd

et al. 2012

Chemistry A European J

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Pyrene-fused tetraazaporphyrins were synthesized from pyrene-4,5-dicarbonitrile precursors using a recently reported procedure as the key step for the asymmetric substitution of pyrene. Metal-free, zinc- and lead-centered pyrenocyanines were obtained and their optical properties as well as their molecular assembly in the solution and bulk phases and at the liquid/solid interface were studied. The characteristic Q-band appears broadened, most likely owing to distortion of the molecule introduced by the steric demand of the angularly extended aromatic residue. The angular annulation does not bathochromically shift the Q-band as far as would have been expected for the linear case. Peripheral substitution with linear and branched alkoxy chains affords solubility of the compounds in organic solvents. The influence of the distinct steric demand of the substituents on aggregation was investigated for metal-centered pyrenocyanines by using temperature-dependent (1)H NMR and UV/Vis spectroscopy. The self-assembly at the liquid/solid interface was studied using scanning tunneling microscopy. The alkoxy substituents facilitate the anchoring of these slightly non-planar molecules on the surface of graphite. Pyrenocyanine molecules form well-ordered 2D arrays in which the molecules are arranged in rows. The angular annulation of the pyrenocyanine residue leads to characteristic adsorption behavior at the liquid/solid interface, in which the molecules adsorb in two different adsorption geometries. The alkoxy side-chains give rise to a discotic columnar superstructure and induce distinct thermotropic behavior. Dependent on the steric demand of the branched chains and the central metal atom, the molecules are rotated with respect to each other to form helical organization.

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“…Phthalocyanines with highly delocalized cyclic p-electron systems show intense absorptions in the red region (Q band) and these absorptions can be shifted to near-IR by making relatively small changes on these molecules [3,4]. Fusion of additional aromatic rings (polybenzannulation) has been proposed as a practical method to enhance the conjugation of p-electrons and so increasing the wavelength of absorbed electromagnetic radiation, but the insolubility of the products obtained here has been almost inevitable [5]. The second way to obtain the same effect has been the addition of electron donating groups (e.g.…”

Section: Introductionmentioning

confidence: 99%