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Effect of the ortho alkylation of perylene bisimides on the alignment and self-assembly properties.

Dasgupta D, Kendhale AM, Debije MG, Ter Schiphorst J, Shishmanova IK, Portale G, Schenning AP - ChemistryOpen (2014)

Bottom Line: The effect of the ortho alkylation of perylene bisimides on the alignment and self-assembly properties has been studied.Furthermore, a solvent-induced growth of ultralong organic n-type semiconducting fibrils from non-ortho-alkylated perylene bisimide was observed.Ortho substitution of the perylene bisimide core alters the mode of fibrillar growth, leading to isotropic crystallization.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Functional Organic Materials and Devices, Eindhoven University of Technology P.O. Box 513, 5600 MB, Eindhoven (The Netherlands) E-mail: a.p.h.j.schenning@tue.nl.

ABSTRACT
The effect of the ortho alkylation of perylene bisimides on the alignment and self-assembly properties has been studied. It was found that the dichroic properties of perylene bisimides in a liquid crystal host can be reversed with a single synthetic step by ortho alkylation. Furthermore, a solvent-induced growth of ultralong organic n-type semiconducting fibrils from non-ortho-alkylated perylene bisimide was observed. Ortho substitution of the perylene bisimide core alters the mode of fibrillar growth, leading to isotropic crystallization.

No MeSH data available.


FESEM images of PB-1 (top) and PB-2 (bottom) solvent dried films (cast from 5 mm dodecane solutions). Scale bars: top left : 500 μm; top right: 20 μm; bottom left: 50 μm; bottom right: 2 μm.
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fig03: FESEM images of PB-1 (top) and PB-2 (bottom) solvent dried films (cast from 5 mm dodecane solutions). Scale bars: top left : 500 μm; top right: 20 μm; bottom left: 50 μm; bottom right: 2 μm.

Mentions: In the next step, we investigated the aggregation behavior of PB-1 and the effect of alkylation of the PB core (PB-2) on the supramolecular organization in solution and in the solid state. In the first experiments, the dyes were dissolved in dodecane and drop cast on a glass surface. Field emission scanning electron microscopic (FESEM) images of the dried samples show that, in case of PB-1, highly anisotropic needle-shaped fibers are formed having an average width of 4 μm and length of several hundred micrometers, some even as long as 1.5 mm (Figure 3; top left). Moreover, the growth appears to be regulated, as there is no evidence of branching. The production of such ultralong fibrillar organization has not been reported previously for these perylene bisimides.12 The use of dodecane as solvent, which has a high boiling point, might have influenced the self- organization due to its slow evaporation rate. In contrast, PB-2 only yielded small bundles of thin fibers growing in all directions from central nucleation points without having global anisotropic domains. The individual fibrils widths measured between 300 and 550 nm with a highly entangled morphology.


Effect of the ortho alkylation of perylene bisimides on the alignment and self-assembly properties.

Dasgupta D, Kendhale AM, Debije MG, Ter Schiphorst J, Shishmanova IK, Portale G, Schenning AP - ChemistryOpen (2014)

FESEM images of PB-1 (top) and PB-2 (bottom) solvent dried films (cast from 5 mm dodecane solutions). Scale bars: top left : 500 μm; top right: 20 μm; bottom left: 50 μm; bottom right: 2 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4232268&req=5

fig03: FESEM images of PB-1 (top) and PB-2 (bottom) solvent dried films (cast from 5 mm dodecane solutions). Scale bars: top left : 500 μm; top right: 20 μm; bottom left: 50 μm; bottom right: 2 μm.
Mentions: In the next step, we investigated the aggregation behavior of PB-1 and the effect of alkylation of the PB core (PB-2) on the supramolecular organization in solution and in the solid state. In the first experiments, the dyes were dissolved in dodecane and drop cast on a glass surface. Field emission scanning electron microscopic (FESEM) images of the dried samples show that, in case of PB-1, highly anisotropic needle-shaped fibers are formed having an average width of 4 μm and length of several hundred micrometers, some even as long as 1.5 mm (Figure 3; top left). Moreover, the growth appears to be regulated, as there is no evidence of branching. The production of such ultralong fibrillar organization has not been reported previously for these perylene bisimides.12 The use of dodecane as solvent, which has a high boiling point, might have influenced the self- organization due to its slow evaporation rate. In contrast, PB-2 only yielded small bundles of thin fibers growing in all directions from central nucleation points without having global anisotropic domains. The individual fibrils widths measured between 300 and 550 nm with a highly entangled morphology.

Bottom Line: The effect of the ortho alkylation of perylene bisimides on the alignment and self-assembly properties has been studied.Furthermore, a solvent-induced growth of ultralong organic n-type semiconducting fibrils from non-ortho-alkylated perylene bisimide was observed.Ortho substitution of the perylene bisimide core alters the mode of fibrillar growth, leading to isotropic crystallization.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Functional Organic Materials and Devices, Eindhoven University of Technology P.O. Box 513, 5600 MB, Eindhoven (The Netherlands) E-mail: a.p.h.j.schenning@tue.nl.

ABSTRACT
The effect of the ortho alkylation of perylene bisimides on the alignment and self-assembly properties has been studied. It was found that the dichroic properties of perylene bisimides in a liquid crystal host can be reversed with a single synthetic step by ortho alkylation. Furthermore, a solvent-induced growth of ultralong organic n-type semiconducting fibrils from non-ortho-alkylated perylene bisimide was observed. Ortho substitution of the perylene bisimide core alters the mode of fibrillar growth, leading to isotropic crystallization.

No MeSH data available.