Limits...
Alkyl- π engineering in state control toward versatile optoelectronic soft materials

View Article: PubMed Central - PubMed

ABSTRACT

Organic π-conjugated molecules with extremely rich and tailorable electronic and optical properties are frequently utilized for the fabrication of optoelectronic devices. To achieve high solubility for facile solution processing and desirable softness for flexible device fabrication, the rigid π units were in most cases attached by alkyl chains through chemical modification. Considerable numbers of alkylated-π molecular systems with versatile applications have been reported. However, a profound understanding of the molecular state control through proper alkyl chain substitution is still highly demanded because effective applications of these molecules are closely related to their physical states. To explore the underlying rule, we review a large number of alkylated-π molecules with emphasis on the interplay of van der Waals interactions (vdW) of the alkyl chains and π–π interactions of the π moieties. Based on our comprehensive investigations of the two interactions’ impacts on the physical states of the molecules, a clear guidance for state control by alkyl-π engineering is proposed. Specifically, either with proper alkyl chain substitution or favorable additives, the vdW and π–π interactions can be adjusted, resulting in modulation of the physical states and optoelectronic properties of the molecules. We believe the strategy summarized here will significantly benefit the alkyl-π chemistry toward wide-spread applications in optoelectronic devices.

No MeSH data available.


(a) Chemical structure of oligoarene derivative 2 containing linear alkyl chains. False-color SEM images of different nanostructures of 2: microbelts self-assembled from 1,4-dioxane (b), flower-A formed from THF (c) and flower-B assembled from n-decane (d). Reprinted with permission from L Wang et al 2009 Langmuir25 1306, © 2009 American Chemical Society.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC5036497&req=5

Figure 2: (a) Chemical structure of oligoarene derivative 2 containing linear alkyl chains. False-color SEM images of different nanostructures of 2: microbelts self-assembled from 1,4-dioxane (b), flower-A formed from THF (c) and flower-B assembled from n-decane (d). Reprinted with permission from L Wang et al 2009 Langmuir25 1306, © 2009 American Chemical Society.

Mentions: Wang et al reported a linear dodecyl chain-substituted oligoarene derivative, 2, which exhibited similar solvent-dependent self-assembly behavior as 1a–1c (figure 2(a)) [28]. By drop casting solutions of 2 in different solvents onto glass substrates, three distinctive structures were obtained after evaporation of the solvents. In 1,4-dioxane, 2 self-assembled into 1D microbelts on the order of tens of micrometers in length, several hundred nanometers in width and 50 nm in thickness (figure 2(b)). However, in THF and n-decane, two different 3D flower-shaped microstructures, flower-A (figure 2(c)) and flower-B (figure 2(d)), were generated. In spite of their similar diameters, around 10–20 μm, flower-A was made of hundreds of shuttle-like 1D petals, while flower-B was composed of hundreds of 1D acicula-like petals. In the light of their high surface areas, the flower-shaped objects were fabricated for explosive detection because the detection scope mainly relied on surface area. The detection speed of 3D flower-B was enhanced by more than 700 times compared with that of the 1D microbelts, providing prospects for using these self-assembled structures in chemosensing.


Alkyl- π engineering in state control toward versatile optoelectronic soft materials
(a) Chemical structure of oligoarene derivative 2 containing linear alkyl chains. False-color SEM images of different nanostructures of 2: microbelts self-assembled from 1,4-dioxane (b), flower-A formed from THF (c) and flower-B assembled from n-decane (d). Reprinted with permission from L Wang et al 2009 Langmuir25 1306, © 2009 American Chemical Society.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5036497&req=5

Figure 2: (a) Chemical structure of oligoarene derivative 2 containing linear alkyl chains. False-color SEM images of different nanostructures of 2: microbelts self-assembled from 1,4-dioxane (b), flower-A formed from THF (c) and flower-B assembled from n-decane (d). Reprinted with permission from L Wang et al 2009 Langmuir25 1306, © 2009 American Chemical Society.
Mentions: Wang et al reported a linear dodecyl chain-substituted oligoarene derivative, 2, which exhibited similar solvent-dependent self-assembly behavior as 1a–1c (figure 2(a)) [28]. By drop casting solutions of 2 in different solvents onto glass substrates, three distinctive structures were obtained after evaporation of the solvents. In 1,4-dioxane, 2 self-assembled into 1D microbelts on the order of tens of micrometers in length, several hundred nanometers in width and 50 nm in thickness (figure 2(b)). However, in THF and n-decane, two different 3D flower-shaped microstructures, flower-A (figure 2(c)) and flower-B (figure 2(d)), were generated. In spite of their similar diameters, around 10–20 μm, flower-A was made of hundreds of shuttle-like 1D petals, while flower-B was composed of hundreds of 1D acicula-like petals. In the light of their high surface areas, the flower-shaped objects were fabricated for explosive detection because the detection scope mainly relied on surface area. The detection speed of 3D flower-B was enhanced by more than 700 times compared with that of the 1D microbelts, providing prospects for using these self-assembled structures in chemosensing.

View Article: PubMed Central - PubMed

ABSTRACT

Organic π-conjugated molecules with extremely rich and tailorable electronic and optical properties are frequently utilized for the fabrication of optoelectronic devices. To achieve high solubility for facile solution processing and desirable softness for flexible device fabrication, the rigid π units were in most cases attached by alkyl chains through chemical modification. Considerable numbers of alkylated-π molecular systems with versatile applications have been reported. However, a profound understanding of the molecular state control through proper alkyl chain substitution is still highly demanded because effective applications of these molecules are closely related to their physical states. To explore the underlying rule, we review a large number of alkylated-π molecules with emphasis on the interplay of van der Waals interactions (vdW) of the alkyl chains and π–π interactions of the π moieties. Based on our comprehensive investigations of the two interactions’ impacts on the physical states of the molecules, a clear guidance for state control by alkyl-π engineering is proposed. Specifically, either with proper alkyl chain substitution or favorable additives, the vdW and π–π interactions can be adjusted, resulting in modulation of the physical states and optoelectronic properties of the molecules. We believe the strategy summarized here will significantly benefit the alkyl-π chemistry toward wide-spread applications in optoelectronic devices.

No MeSH data available.