Self-Assembly of Dendronized Perylene Bisimides into Complex Helical Columns

Abstract

The synthesis of perylene 3,4:9,10-tetracarboxylic acid bisimides (PBIs) dendronized with first-generation dendrons containing 0 to 4 methylenic units (m) between the imide group and the dendron, (3,4,5)12G1-m-PBI, is reported. Structural analysis of their self-organized arrays by DSC, X-ray diffraction, molecular modeling, and solid-state (1)H NMR was carried out on oriented samples with heating and cooling rates of 20 to 0.2 °C/min. At high temperature, (3,4,5)12G1-m-PBI self-assemble into 2D-hexagonal columnar phases with intracolumnar order. At low temperature, they form orthorhombic (m = 0, 2, 3, 4) and monoclinic (m = 1) columnar arrays with 3D periodicity. The orthorhombic phase has symmetry close to hexagonal. For m = 0, 2, 3, 4 ,they consist of tetramers as basic units. The tetramers contain a pair of two molecules arranged side by side and another pair in the next stratum of the column, turned upside-down and rotated around the column axis at different angles for different m. In contrast, for m = 1, there is only one molecule in each stratum, with a four-strata 2(1) helical repeat. All molecules face up in one column, and down in the second column, of the monoclinic cell. This allows close and extended π-stacking, unlike in the disruptive up-down alteration from the case of m = 0, 2, 3, 4. Most of the 3D structures were observed only by cooling at rates of 1 °C/min or less. This complex helical self-assembly is representative for other classes of dendronized PBIs investigated for organic electronics and solar cells.

Increasing 3D Supramolecular Order by Decreasing Molecular Order. A Comparative Study of Helical Assemblies of Dendronized Nonchlorinated and Tetrachlorinated Perylene Bisimides

“…5,6 Practical applications of these systems are hampered by many issues, including poor solubility, high melting temperatures, air sensitivity, difficult processability, low charge carrier mobilities and short charge carrier lifetimes. 1,[6][7][8] Furthermore, the kinetically controlled polymorphism of large PBI assemblies hinders their structural analysis, [9][10][11] especially by commonly-used single crystal X-ray diffraction analysis. Functionalization of the bay positions of PBI with halogens including fluorine, chlorine and bromine has been proven to address some of the limitations of non-halogenated PBI building blocks.…”

“…[9][10][11] The PBI derivatives self-organized to form a range of 2D and 3D phases, of which the least encountered 3D thermodynamic products are the most desirable for technological applications. 11 Here we report the synthesis and structural analysis of five Cl 4 PBI derivatives with n and m chosen to promote thermodynamically controlled formation of 3D crystalline phases.…”

“…11 Here we report the synthesis and structural analysis of five Cl 4 PBI derivatives with n and m chosen to promote thermodynamically controlled formation of 3D crystalline phases. [9][10][11] Cl 4 PBI compounds were synthesized with m = 0, 1, 2, 3 and 2EO (where EO is ethylene oxide, -CH 2 CH 2 O-), functionalized at their imide groups with first generation self-assembling dendrons with either dodecyl groups (8a, 8b and 8c with m = 0, 1 and 2, respectively) or semifluorinated groups, -CH 4 (CF 2 ) 7 CF 3 (denoted 12F8; 9 and 3 11 with m = 3 and 2EO, respectively), at the periphery of the dendrons. A detailed structural study of the assemblies formed by these Cl 4 PBI derivatives is described and compared with the self-assembling behavior of non-chlorinated PBI derivatives.…”

Self-Assembly of Dendritic Dipeptides as a Model of Chiral Selection in Primitive Biological Systems

“…Thus, it was shown that supramolecular interactions of a chiral electron-acceptor molecule with a columnar supramolecular dendrimer selects the twist sense of the helical column [52], while the covalent attachment of a chiral alkyl chain at the periphery of a C 3 -symmetric dendrimer mediates transfer, amplification, and thermal inversion of chirality in the corresponding supramolecular assembly [85]. Similarly, a homochiral unit could potentially be introduced in other electronic materials composed of donor/acceptor self-assembled dendrimers [30,86,87] in order to tune their structural and electronic properties. This strategy could also be used to monitor the structure and function of self-organizable dendronized polymers.…”

Utilizing Perylene in New Organic Donor–Acceptor Materials: Highlighting the Synthesis, Structure and Physical Properties of Perylene-pDNB and Perylene-TCNP

“…While Perylene has been utilized in the synthesis of multiple charge transfer salts, it has also been integrated into organometallic complexes having ruthenium, palladium and silver metal centers and as essential components within Perylene 3,4:9,10-tetracarboxylic acid bisimides (PBIs), the latter being building blocks having applications as pigments, protein tags, and within organic field effect transistors (OFETs) and organic solar cells due to their robust photochemical, thermal stability and high fluorescence quantum yields [13][14][15][16][17][18][19][20][21][22]. In addition to these, Perylene has also been co-crystallized with various organic acceptors, among them TCNQ (TCNQ = 7,7,8,8-tetracyanoquinodimethane) with which it forms both 1:1 and 3:1 phases and fluoranil (fluoranil = 2,3,5,6-tetrafluoro-1,4-benzoquinone), complexes known to be photoconductors [23][24][25][26][27].…”