Hierarchical Corannulene‐Based Materials: Energy Transfer and Solid‐State Photophysics

Abstract

Abstract:We report the first example of ad onor-acceptor corannulene-containing hybrid material with rapid ligand-toligand energy transfer (ET). Additionally,weprovide the first time-resolved photoluminescence (PL) data for any corannulene-based compounds in the solid state.C omprehensive analysis of PL data in combination with theoretical calculations of donor-acceptor exciton coupling was employed to estimate ET rate and efficiency in the prepared material. The ligand-to-ligand ET rate calculated using two models is comparable with that observed in fullerene-containing materials,w hich are generally considered for molecular electronics development. Thus,the presented studies not only demonstrate the possibility of merging the intrinsic properties of p-bowls, specifically corannulene derivatives,w ith the versatility of crystalline hybrid scaffolds,b ut could also foreshadowt he engineering of anovel class of hierarchicalcorannulene-based hybrid materials for optoelectronic devices.While the compromise between strain and aromaticity is ap ersistent synthetic challenge, [1][2][3] the bowl shape and electronic properties of corannulene derivatives (buckybowls, Scheme 1) imply an unrevealed potential for molecular electronics development similar to their close famous analogues,fullerenes.The main success of the latter in the field of optoelectronics is associated with very fast energy/electron transfer, which has been demonstrated in numerous photophysical studies. [4][5][6] In contrast, development of buckybowlcontaining materials with desirable properties is still in its infancy. Fori nstance,d uring the 50 years since the discovery of the first solution route for corannulene preparation (1966), [1] only around 20 papers [2, include any photophysical studies,d espite nearly 1000 publications focused on corannulene.T othe best of our knowledge,there are only two reports [8,10] in the area of corannulene solid-state photophysics.F urthermore,n os olid-state time-resolved photoluminescence (PL) data or energy transfer (ET) studies have been reported for any corannulene-containing compounds despite the fact that ET rate and efficiency are crucial fundamental parameters for applications ranging from organic photovoltaics to photocatalysis. [33,34] This gap in material development was the major driving force to initiate the presented study,especially taking into account the recent progress in corannulene chemistry. [35] Our shift from more traditional flat aromatic hydrocarbons [36] towards p-bowls (for example,c orannulene) was also driven by 1) their significant dipole moment, 2) the possibility to extend the dimensionality of 3D hybrid frameworks through the p-bowl curvature,3 )potential for charge stabilization on the surface owing to doubly degenerate lowest unoccupied molecular orbitals (LUMOs), 4) anticipated effective intermolecular charge transport, and 5) presence of theoretically predicted super atomic molecular orbitals,w hich are key factors for intermolecular charge/ energy transport distinct from the c...

Hydrogen-bonded porous frameworks constructed by rigid π-conjugated molecules with carboxy groups

“…Non-planar bowl-shaped C 3 PIs, on the other hand, seem to be difficult to form the same a planar 2D H-HexNets. The author became interested in a periodic H-bonded framework composed of bowl-shaped π-conjugated molecules, although a handful examples of MOFs based on corannulene and sumanene were reported [103][104][105]. Such structure can provide useful information how curved molecules accomplish fully H-bonded, networked structures.…”

Fulleretic Materials: Buckyball- and Buckybowl-Based Crystalline Frameworks

“…61 The same corannulene linker 6 was utilized to probe coordination with other metals such as cadmium, which resulted in the formation of a three-dimensional framework. 20 Interestingly, the curvature of the corannulene bowl remains intact inside all reported corannulene-based MOFs, which provides an opportunity to extend MOF dimensionaility 20,61 for applications such as molecular recognition, 67−69 alkali-metal intercalation, 31,39 or separation (Figure 6). 70 Those studies are in line with the fascinating report by Petrukhina and co-workers who described preparation of a corannulene "sandwich" intercalated with lithium.…”

“…13−16 For instance, [6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM) is one of the most explored acceptors for development of bulk heterojunction solar cells. 13,17,18 Along with their superior electron-accepting properties, fullerene and its derivatives are known for ultrafast electron/energy transfer (ET), 14,19,20 which in combination with high electron mobility 21 makes buckyballs attractive candidates for molecular electronics development. The appeal to use fulleretic materials as components for optoelectronic devices also stems from their broad absorption profile and exceptional thermal stability (up to 500 °C).…”

“…The same tetrabromocorannulene utilized for preparation of 6 was employed for preparation of a pyridyl-containing corannulene derivative (7, Figure 2). 20 Compound 7 was dually used for both the synthesis of (i) a 2D silver-based MOF and (ii) a donor−acceptor framework. The latter one was explored to study the possibility of FRET in the system through utilization of a two-step synthetic approach, in which a 2D porphyrin-based layered MOF was synthesized first, followed by the immobilization of a new corannulene-based derivative as a pillar.…”

Hierarchical Nanoparticle Assemblies Formed via One-Step Catalytic Stamp Pattern Transfer

“…A number of artificial hierarchical structures were designed to mimic nature and to explore potential applications in tissue engineering, 10,11 electronics, 12,13 and optoelectronic applications. 14,15 However, precise control of the relative position and molecular orientation in two-dimension or three-dimension still remain a current challenge in fabrication of artificial, functional hierarchical structures. Current state-of-the-art fabrication approaches to produce artificial hierarchical structures include sequential multistep lithography, 16−20 lithography combined with molecular self-assembly, 21−25 and layer-by-layer (LbL) assembly techniques.…”