Liquid Crystalline Perylene Diimides: Architecture and Charge Carrier Mobilities
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- 作者：Corien W. Struijk ; Alexander B. Sieval ; Jarno E. J. Dakhorst ; Marinus van Dijk ; Peter Kimkes ; Rob B. M. Koehorst ; Harry Donker ; Tjeerd J. Schaafsma ; Stephen J. Picken ; Anick M. van de Craats ; John M.
- 刊名：Journal of the American Chemical Society
- 出版年：2000
- 出版时间：November 15, 2000
- 年：2000
- 卷：122
- 期：45
- 页码：11057 - 11066
- 全文大小：350K
- 年卷期：v.122,no.45(November 15, 2000)
- ISSN：1520-5126
文摘
The phase behavior of three N-alkyl-substituted perylene diimide derivatives is examined bydifferential scanning calorimetry and polarized optical microscopy. The occurrence of multiple phase transitionsindicates several crystalline and several liquid crystalline phases. X-ray diffraction measurements show thatthe liquid crystalline phases display high structural ordering in all three dimensions: smectic layers are formed,and within these smectic layers an additional ordering in columns is observed. Molecular modeling confirmsthis result and substantiates smectic ordering with interdigitating alkyl chains that determine the distance betweenthe smectic layers. The ordering in columns is favored by 
- interactions between the cofacially orientedperylene molecules and by the elliptic shape of the molecule. Finally, intermolecular dipole-dipole interactionsbetween the carbonyl groups of the imide moieties cause the perylene molecules to orient on average with aslight rotation between neighboring molecules within a columnar stack. Following the determination of theelectronic transition dipole moment, this orientation, which still involves substantial - interactions, couldbe confirmed by UV/vis spectroscopy of perylene aggregates. To gauge the potential of these materials asorganic semiconductors, the charge carrier mobility of one of the perylene derivatives has been measured bypulse-radiolysis time-resolved microwave conductivity. A value in excess of 0.1 cm2 V-1 s-1 is found in theliquid crystalline phase, and a value in excess of 0.2 cm2 V-1 s-1 is found for the crystalline phase. Thesevalues are comparable with the highest values previously found for other discotic materials.
- interactions between the cofacially orientedperylene molecules and by the elliptic shape of the molecule. Finally, intermolecular dipole-dipole interactionsbetween the carbonyl groups of the imide moieties cause the perylene molecules to orient on average with aslight rotation between neighboring molecules within a columnar stack. Following the determination of theelectronic transition dipole moment, this orientation, which still involves substantial - interactions, couldbe confirmed by UV/vis spectroscopy of perylene aggregates. To gauge the potential of these materials asorganic semiconductors, the charge carrier mobility of one of the perylene derivatives has been measured bypulse-radiolysis time-resolved microwave conductivity. A value in excess of 0.1 cm2 V-1 s-1 is found in theliquid crystalline phase, and a value in excess of 0.2 cm2 V-1 s-1 is found for the crystalline phase. Thesevalues are comparable with the highest values previously found for other discotic materials.