Organic Semiconductor-Containing Supramolecules: Effect of Small Molecule Crystallization and Molecular Packing

Abstract

Small molecules (SMs) with unique optical or electronic properties provide an opportunity to incorporate functionality into block copolymer (BCP)-based supramolecules. However, the assembly of supramolecules based on these highly crystalline molecules differs from their less crystalline counterparts. Here, two families of organic semiconductor SMs are investigated, where the composition of the crystalline core, the location (side- vs end-functionalization) of the alkyl solubilizing groups, and the constitution (branched vs linear) of the alkyl groups are varied. With these SMs, we present a systematic study of how the phase behavior of the SMs affects the overall assembly of these organic semiconductor-based supramolecules. The incorporation of SMs has a large effect on the interfacial curvature, the supramolecular periodicity, and the overall supramolecular morphology. The crystal packing of the SM within the supramolecule does not necessarily lead to the assembly of the comb block within the BCP microdomains, as is normally observed for alkyl-containing supramolecules. An unusual lamellar morphology with a wavy interface between the microdomains is observed due to changes in the packing structure of the small molecule within BCP microdomains. Since the supramolecular approach is modular and small molecules can be readily switched out, present studies provide useful guidance toward access supramolecular assemblies over several length scales using optically active and semiconducting small molecules.

Nanocomposites Based on Coil-Comb Diblock Copolymers

“…The train-track morphology mainly contains lamellar structures with certain regions rich in short-range ordered cylindrical structures or line-bridging defects (Figure h), essentially mixed morphologies of lamellar and cylindrical structures. The SAXS profile of P5 has a small first-order peak and no well-defined high-order peaks, which possibly reflects the mixed morphologies and the relatively large Đ in P5. The absence of several high-order peaks in P4 could also be attributed to the mixed morphologies.…”

Development of Dithieno[3,2-b:2′,3′-d]thiophene (DTT) Derivatives as Solution-Processable Small Molecular Semiconductors for Organic Thin Film Transistors

“…Higher melting temperature of compounds 2 and 3 than that of compound 1 is due to stronger intermolecular interaction with more thiophene rings [58]. Similarly, linear alkyl chain (-octyl) of compound 2 could promote stronger intermolecular interactions than branched alkyl side chain (-ethylhexyl) of compound 3, resulting in slightly higher melting temperature of compound 2 [59,60]. The optical properties of the compounds in diluted chloroform solution were investigated by the UV-vis spectroscopy (Figure 2).…”

Directed Assembly of Hierarchical Supramolecular Block Copolymers: A Strategy To Create Donor–Acceptor Charge-Transfer Stacks

“…30−40 Among these, the works on organic semiconductor-containing supramolecules attracted great interest from researchers as this approach creates a new avenue to tailor the electronic properties of composites in addition to the structural control. [34][35][36]38,39 However, the major focus in this field is so far on the addition of a single small molecule to polymers for the formation of SMA. In contrast, the multicomponent assembly is rarely achieved, despite its high promises for the creation of novel nanosized composite materials, possibly because of the commonly encountered problem of phase separation.…”

“…Noncovalent polymer side-chain modification has emerged as a powerful tool for the creation of nanostructured materials with hierarchical morphologies and desirable properties. , Ikkala and ten Brinke demonstrated the formation of hierarchical structures through the complexation of a small molecule with the block copolymer by hydrogen bonding. − Later, several groups adopted this supramolecular assembly (SMA) approach to generate nanostructured composites for diverse applications. − Among these, the works on organic semiconductor-containing supramolecules attracted great interest from researchers as this approach creates a new avenue to tailor the electronic properties of composites in addition to the structural control. − ,, However, the major focus in this field is so far on the addition of a single small molecule to polymers for the formation of SMA. In contrast, the multicomponent assembly is rarely achieved, despite its high promises for the creation of novel nanosized composite materials, possibly because of the commonly encountered problem of phase separation.…”