Multicomponent Molecular Assembly of Fluorescent Organic Semiconductors Beyond Three Compounds

Abstract

In contrast to unary assemblies comprising π-conjugated organic species, elaborate modulation of dimensions, polymorphisms, and compositions of multicomponent assembled architectures with two or more constituent materials has not yet been systematically studied. Herein, a combinatorial library of organic microcrystals made of four components via a solutionphase assembly route is reported. With the involvement of growth kinetics, four organic species with slight structural modifications can assemble into five unary assemblies, which may endow binary combinations with highly and partially structural miscibility. Consequently, a variety of binary alloyed assemblies and microscale heterostructures with tailorable dimensions, polymorphisms, and emission colors are realized by rational compositional and growth control. The effects of structural relations of binary combinations on their miscibility are systematically uncovered, that gives rise to these intricate microscale architectures as well as diverse energy transfer (ET) efficiencies. Highly efficient ET process in binary alloyed assemblies can be beneficial to steady-state photoluminescence anisotropy amplification. Benefiting from the information of binary combinations, white-light-emitting ternary microsheets can be modulated in a predictable manner. The present work uncovers the rational control of multicomponent microcrystals, which further stretches the boundaries of molecular self-assembly and may be used to achieve integrated optoelectronic properties, such as multicolor lasers and p-n junctions.

Homogeneous and Heterogeneous Self‐Assembly of Luminescent Pyromellitic Dianhydride‐Based Charge‐Transfer Complexes

“…Upon alloying, Fl 1− x An x ‐PMDA alloyed assemblies show improved PL anisotropy and ρ increases from 0.24 at x = 0 to 0.37 at x = 10%, which is comparable to pure An‐PMDA ( ρ = 0.38). Similar to the cases of the binary alloyed assemblies consisting of unary organic semiconductors, [ 31 ] we deduced that such a PL anisotropy amplification arises from efficient ET processes from Fl‐PMDA to An‐PMDA.…”

“…[22][23][24] Alternatively, organic alloys are also preliminarily developed by random substitution of a host matrix with structurally matched guest molecules. [30][31][32][33][34][35][36] A representative case is that a 9,10-bis(phenylethynyl)anthracene (BA) host with a planar molecular geometry can provide lattice sites to allow for the occupation of structurally twisted 5,12bis(phenylethynyl)naphthacene (BN) over a wide composition range, giving homogeneous alloys of BA and BN. [30] Apart from these, the heteroepitaxial growth of one organic compound onto the prefabricated organic crystals is also accessible when the epitaxial relationships between two 𝜋-conjugated materials are met.…”

“…[ 19–21 ] Among them, binary organic assembled architectures are of particular interest considering that new crystal structures and/or functionality may be involved. [ 22–40 ] Based on the spatial distribution of two constituent materials, these binary assemblies can be divided into homogeneous and heterogeneous structures. The binary material combinations capable of generating periodic molecular arrangements or random molecular substitutions are considered homogeneous systems, whereas the combinations capable of producing heterogeneous interfaces at the micro‐ and nanoscale are viewed as heterogeneous systems.…”

“…[ 36 ] The former corresponds to organic cocrystals with fixed stoichiometric ratios or organic alloys with arbitrary stoichiometric ratios in which noncovalent intermolecular interactions between two components such as charge‐transfer (CT), hydrogen‐bonding, and host‐guest inclusion interactions or their similarity in molecular shapes and sizes should be guaranteed. [ 9,22–36 ] On the contrary, the selective growth of one component onto the pre‐existing crystals of another component gives rise to heterostructured architectures. [ 37–40 ] The rational creation of new heterogeneous interfaces across different scales in these binary organic assemblies facilitates photon and charge transport and may lead to integrated or improved optoelectronic performance applications.…”

Fractal Branched Microwires of Organic Semiconductor with Controlled Branching and Low-Threshold Amplified Spontaneous Emission

“…As reported previously, as the molecular skeleton of OPV-A, DSB can assemble into microribbons that allow branching growth of structurally similar BA MRs. Such an epitaxial growth strategy − may be a solution to address the issue. On this basis, structure- and/or size-matched components such as 9,10-dicyanoanthracene (DCA), 9,10-dibromoanthracene (DBA), BA, etc.…”