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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.


Photographs of perylene bisimide dodecane solutions (5 mm) at the indicated temperatures taken under normal light for PB-2 (top) and PB-1 (bottom).
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fig04: Photographs of perylene bisimide dodecane solutions (5 mm) at the indicated temperatures taken under normal light for PB-2 (top) and PB-1 (bottom).

Mentions: It was also observed that in a 5 mm solution in dodecane, PB-2 is completely soluble at 140 οC and that aggregates start to appear upon quenching to 20 οC (Figure 4, top). Unlike PB-2, PB-1 does not seem to dissolve completely in dodecane, even at elevated temperature (approx. 160 οC), as the dispersion lacks transparency (Figure 4, bottom). Most likely a small fraction of associated perylene bisimide nanocrystals act as seeds to nucleate the unidirectional growth of ultralong fibers. As earlier reported, most likely so-called H-type aggregates are formed in which the fluorescence is quenched.14


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)

Photographs of perylene bisimide dodecane solutions (5 mm) at the indicated temperatures taken under normal light for PB-2 (top) and PB-1 (bottom).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig04: Photographs of perylene bisimide dodecane solutions (5 mm) at the indicated temperatures taken under normal light for PB-2 (top) and PB-1 (bottom).
Mentions: It was also observed that in a 5 mm solution in dodecane, PB-2 is completely soluble at 140 οC and that aggregates start to appear upon quenching to 20 οC (Figure 4, top). Unlike PB-2, PB-1 does not seem to dissolve completely in dodecane, even at elevated temperature (approx. 160 οC), as the dispersion lacks transparency (Figure 4, bottom). Most likely a small fraction of associated perylene bisimide nanocrystals act as seeds to nucleate the unidirectional growth of ultralong fibers. As earlier reported, most likely so-called H-type aggregates are formed in which the fluorescence is quenched.14

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.