Organization of Acenes with a Cruciform Assembly Motif

Abstract

This study explores the assembly in the crystalline state of a class of pentacenes that are substituted along their long edges with aromatic rings forming rigid, cruciform molecules. The crystals were grown from the gas phase, and their structures were compared with DFT-optimized geometries. Both crystallographic and computed structures show that a planar acene core is the exception rather than the rule. In the assembly of these molecules, the phenyl groups block the herringbone motif and further guide the arrangement of the acene core into higher order structures. The packing for the phenyl-substituted derivatives is dictated by close contacts between the C-H's of the pendant aromatic rings and the carbons at the fusions in the acene backbone. Using thiophene substituents instead of phenyls creates cofacially stacked acenes. In thin films, the thiophene-substituted derivative forms devices with good electrical properties: relatively high mobility, high ON/OFF ratios, and low threshold voltage for device activation. An unusual result is obtained for the decaphenyl pentacene when devices are fabricated on its crystalline surface. Although its acene cores are well isolated from each other, this material still exhibits good electrical properties.

Photoresponsive nanoscale columnar transistors

“…1B and then deposit the materials on the top of the substrate through thermal evaporation. An advantage of this molecule is its cofacially arranged -stacking crystal structure (33), which will make a nice contact between SWNT electrodes and molecules (Fig. S5A).…”

Organic Crystals with Tunable Emission Colors Based on a Single Organic Molecule and Different Molecular Packing Structures

“…Although considerable progress has been made in organic luminescent materials with different molecular structures, [9][10][11][12][13][14][15][16][17][18][19][20][21] it is still essential to achieve a molecular-level understanding of the relationship between the molecular packing characteristics of organic materials and the resulting optical properties. [22][23][24][25][26] Hydrogen bonding and p_p stacking are two kinds of important intermolecular interactions for the construction of functional supramolecular systems. Furthermore, noncovalent intermolecular interactions such as hydrogen bonding, p_p interactions, and the presence of solvent molecules are all able to influence strongly the final packing structure, making polymorphism more probable.…”

Syntheses and properties of copolymers containing indolocarbazole moiety in the side chain

“…[1][2][3][4][5][6][7] In particular, organic compounds that possess a p-conjugated system, such as pentacene and oligothiophene, have attracted much attention [8][9][10][11][12][13] because of their mechanical properties, low cost and variety of photonic properties obtained by chemical modification. Therefore, significant progress has been made in the study of p-conjugated organic compounds, which might be competitive with amorphous silicon in electronic and photonic devices.…”