Dibenzochrysene Enables Tightly Controlled Docking and Stabilizes Photoexcited States in Dual-Pore Covalent Organic Frameworks

Author(s):  
Torben Sick ◽  
Niklas Keller ◽  
Nicolai Bach ◽  
Andreas Koszalkowski ◽  
Julian Rotter ◽  
...  

Covalent organic frameworks (COFs), consisting of covalently connected organic building units, combine attractive features such as crystallinity, open porosity and widely tunable physical properties. For optoelectronic applications, the incorporation of heteroatoms into a 2D COF has the potential to yield desired photophysical properties such as lower band gaps, but can also cause lateral offsets of adjacent layers. Here, we introduce dibenzo[g,p]chrysene (DBC) as a novel building block for the synthesis of highly crystalline and porous 2D dual-pore COFs showing interesting properties for optoelectronic applications. The newly synthesized terephthalaldehyde (TA), biphenyl (Biph), and thienothiophene (TT) DBC-COFs combine conjugation in the a,b-plane with a tight packing of adjacent layers guided through the molecular DBC node serving a specific docking site for successive layers. The resulting DBC-COFs exhibit a hexagonal dual-pore kagome geometry, which is comparable to COFs containing another molecular docking site, namely 4,4′,4″,4‴-(ethylene-1,1,2,2-tetrayl)-tetraaniline (ETTA). In this context, the respective interlayer distances decrease from about 4.60 Å in ETTA-COFs to about 3.6 Å in DBC-COFs, leading to well-defined hexagonally faceted single crystals sized about 50-100 nm. The TT DBC-COFs feature broad light absorption covering large parts of the visible spectrum, while Biph DBC-COF shows extraordinary excited state lifetimes exceeding 10 ns. In combination with the large number of recently developed linear conjugated building blocks, the new DBC tetra-connected node is expected to enable the synthesis of a large family of strongly p-stacked, highly ordered 2D COFs with promising optoelectronic properties.

2019 ◽  
Author(s):  
Niklas Keller ◽  
Torben Sick ◽  
Nicolai Bach ◽  
Andreas Koszalkowski ◽  
Julian Rotter ◽  
...  

Covalent organic frameworks (COFs), consisting of covalently connected organic building units, combine attractive features such as crystallinity, open porosity and widely tunable physical properties. For optoelectronic applications, the incorporation of heteroatoms into a 2D COF has the potential to yield desired photophysical properties such as lower band gaps, but can also cause lateral offsets of adjacent layers. Here, we introduce dibenzo[g,p]chrysene (DBC) as a novel building block for the synthesis of highly crystalline and porous 2D dual-pore COFs showing interesting properties for optoelectronic applications. The newly synthesized terephthalaldehyde (TA), biphenyl (Biph), and thienothiophene (TT) DBC-COFs combine conjugation in the a,b-plane with a tight packing of adjacent layers guided through the molecular DBC node serving a specific docking site for successive layers. The resulting DBC-COFs exhibit a hexagonal dual-pore kagome geometry, which is comparable to COFs containing another molecular docking site, namely 4,4′,4″,4‴-(ethylene-1,1,2,2-tetrayl)-tetraaniline (ETTA). In this context, the respective interlayer distances decrease from about 4.60 Å in ETTA-COFs to about 3.6 Å in DBC-COFs, leading to well-defined hexagonally faceted single crystals sized about 50-100 nm. The TT DBC-COFs feature broad light absorption covering large parts of the visible spectrum, while Biph DBC-COF shows extraordinary excited state lifetimes exceeding 10 ns. In combination with the large number of recently developed linear conjugated building blocks, the new DBC tetra-connected node is expected to enable the synthesis of a large family of strongly p-stacked, highly ordered 2D COFs with promising optoelectronic properties.


Author(s):  
Niklas Keller ◽  
Torben Sick ◽  
Nicolai Bach ◽  
Andreas Koszalkowski ◽  
Julian Rotter ◽  
...  

Covalent organic frameworks (COFs), consisting of covalently connected organic building units, combine attractive features such as crystallinity, open porosity and widely tunable physical properties. For optoelectronic applications, the incorporation of heteroatoms into a 2D COF has the potential to yield desired photophysical properties such as lower band gaps, but can also cause lateral offsets of adjacent layers. Here, we introduce dibenzo[g,p]chrysene (DBC) as a novel building block for the synthesis of highly crystalline and porous 2D dual-pore COFs showing interesting properties for optoelectronic applications. The newly synthesized terephthalaldehyde (TA), biphenyl (Biph), and thienothiophene (TT) DBC-COFs combine conjugation in the a,b-plane with a tight packing of adjacent layers guided through the molecular DBC node serving a specific docking site for successive layers. The resulting DBC-COFs exhibit a hexagonal dual-pore kagome geometry, which is comparable to COFs containing another molecular docking site, namely 4,4′,4″,4‴-(ethylene-1,1,2,2-tetrayl)-tetraaniline (ETTA). In this context, the respective interlayer distances decrease from about 4.60 Å in ETTA-COFs to about 3.6 Å in DBC-COFs, leading to well-defined hexagonally faceted single crystals sized about 50-100 nm. The TT DBC-COFs feature broad light absorption covering large parts of the visible spectrum, while Biph DBC-COF shows extraordinary excited state lifetimes exceeding 10 ns. In combination with the large number of recently developed linear conjugated building blocks, the new DBC tetra-connected node is expected to enable the synthesis of a large family of strongly p-stacked, highly ordered 2D COFs with promising optoelectronic properties.


2020 ◽  
Author(s):  
Hui Li ◽  
Fengqian Chen ◽  
Xinyu Guan ◽  
JIali Li ◽  
Cuiyan Li ◽  
...  

<a>The growth of three-dimensional covalent organic frameworks (3D COFs) with new topologies is still considered as a great challenge due to limited availability of high-connectivity building units. Here we report the design and synthesis of novel 3D triptycene-based COFs, </a><a></a><a>termed</a> JUC-568 and JUC-569, following the deliberate symmetry-guided design principle. By combining a triangular prism (6-connected) node with a planar triangle (3-connected) or another triangular prism node, the targeted COFs adopt unreported <b>ceq </b>or non-interpenetrated <b>acs</b> topology, respectively. <a>Both materials</a> show permanent porosity and impressive performance <a>in the adsorption of CO<sub>2</sub></a> (~ 98 cm<sup>3</sup>/g at 273 K and 1 bar), CH<sub>4</sub> (~ 48 cm<sup>3</sup>/g at 273 K and 1 bar), and especially H<sub>2</sub> (up to 274 cm<sup>3</sup>/g or 2.45 wt% at 77 K and 1 bar), which is <a>highest </a>among <a>porous organic materials</a> reported to date. This research thus provides a promising strategy for diversifying 3D COFs based on complex building blocks and promotes their <a></a><a>potential applications</a> <a>in</a><a></a><a> energy storage and environment-related field</a>s.


2010 ◽  
Vol 1 ◽  
pp. 60-70 ◽  
Author(s):  
Binit Lukose ◽  
Agnieszka Kuc ◽  
Johannes Frenzel ◽  
Thomas Heine

The concept of reticular chemistry is investigated to explore the applicability of the formation of Covalent Organic Frameworks (COFs) from their defined individual building blocks. Thus, we have designed, optimized and investigated a set of reported and hypothetical 2D COFs using Density Functional Theory (DFT) and the related Density Functional based tight-binding (DFTB) method. Linear, trigonal and hexagonal building blocks have been selected for designing hexagonal COF layers. High-symmetry AA and AB stackings are considered, as well as low-symmetry serrated and inclined stackings of the layers. The latter ones are only slightly modified compared to the high-symmetry forms, but show higher energetic stability. Experimental XRD patterns found in literature also support stackings with highest formation energies. All stacking forms vary in their interlayer separations and band gaps; however, their electronic densities of states (DOS) are similar and not significantly different from that of a monolayer. The band gaps are found to be in the range of 1.7–4.0 eV. COFs built of building blocks with a greater number of aromatic rings have smaller band gaps.


2020 ◽  
Author(s):  
Hui Li ◽  
Fengqian Chen ◽  
Xinyu Guan ◽  
JIali Li ◽  
Cuiyan Li ◽  
...  

<a>The growth of three-dimensional covalent organic frameworks (3D COFs) with new topologies is still considered as a great challenge due to limited availability of high-connectivity building units. Here we report the design and synthesis of novel 3D triptycene-based COFs, </a><a></a><a>termed</a> JUC-568 and JUC-569, following the deliberate symmetry-guided design principle. By combining a triangular prism (6-connected) node with a planar triangle (3-connected) or another triangular prism node, the targeted COFs adopt unreported <b>ceq </b>or non-interpenetrated <b>acs</b> topology, respectively. <a>Both materials</a> show permanent porosity and impressive performance <a>in the adsorption of CO<sub>2</sub></a> (~ 98 cm<sup>3</sup>/g at 273 K and 1 bar), CH<sub>4</sub> (~ 48 cm<sup>3</sup>/g at 273 K and 1 bar), and especially H<sub>2</sub> (up to 274 cm<sup>3</sup>/g or 2.45 wt% at 77 K and 1 bar), which is <a>highest </a>among <a>porous organic materials</a> reported to date. This research thus provides a promising strategy for diversifying 3D COFs based on complex building blocks and promotes their <a></a><a>potential applications</a> <a>in</a><a></a><a> energy storage and environment-related field</a>s.


2019 ◽  
Author(s):  
Patricia Scheurle ◽  
Andre Mähringer ◽  
Andreas Jakowetz ◽  
Pouya Hosseini ◽  
Alexander Richter ◽  
...  

Recently, a small group of metal-organic frameworks (MOFs) has been discovered featuring substantial charge transport properties and electrical conductivity, hence promising to broaden the scope of potential MOF applications in fields such as batteries, fuel cells and supercapacitors. In combination with light emission, electroactive MOFs are intriguing candidates for chemical sensing and optoelectronic applications. Here, we incorporated anthracene-based building blocks into the MOF-74 topology with five different divalent metal ions, that is, Zn2+, Mg2+, Ni2+, Co2+ and Mn2+, resulting in a series of highly crystalline MOFs, coined ANMOF-74(M). This series of MOFs features substantial photoluminescence, with ANMOF-74(Zn) emitting across the whole visible spectrum. The materials moreover combine this photoluminescence with high surface areas and electrical conductivity. Compared to the original MOF-74 materials constructed from 2,5-dihydroxy terephthalic acid and the same metal ions Zn2+, Mg2+, Ni2+, Co2+ and Mn2+, we observed a conductivity enhancement of up to six orders of magnitude. Our results point towards the importance of building block design and the careful choice of the embedded MOF topology for obtaining materials with desired properties such as photoluminescence and electrical conductivity.


Author(s):  
Junke Jiang ◽  
Feng Liu ◽  
Qing Shen ◽  
Shuxia Tao

Narrow-bandgap CsSnxPb1-xI3 perovskite quantum dots (QDs) show great promise for optoelectronic applications owing to their reduced use of toxic Pb, improved phase stability, and tunable band gaps in the visible...


2021 ◽  
Author(s):  
Anurag Mukherjee ◽  
Suhrit Ghosh

Naphthalene-diimide (NDI) derived building blocks have been explored extensively for supramolecular assembly as they exhibit attractive photophysical properties, suitable for applications in organic optoelectronics. Core-substituted derivatives of the NDI chromophore (cNDI) differ significantly from the parent NDI dye in terms of optical and redox properties. Adequate molecular engineering opportunities and substitution-dependent tunable optoelectronic properties make cNDI derivatives highly promising candidates for supramolecular assembly and functional material. This short review discusses recent development in the area of functional supramolecular assemblies based on cNDIs and related molecules.


2019 ◽  
Vol 15 ◽  
pp. 2013-2019 ◽  
Author(s):  
Esther Nieland ◽  
Oliver Weingart ◽  
Bernd M Schmidt

ortho-Fluoroazobenzenes are a remarkable example of bistable photoswitches, addressable by visible light. Symmetrical, highly fluorinated azobenzenes bearing an iodine substituent in para-position were shown to be suitable supramolecular building blocks both in solution and in the solid state in combination with neutral halogen bonding acceptors, such as lutidines. Therefore, we investigate the photochemistry of a series of azobenzene photoswitches. Upon introduction of iodoethynyl groups, the halogen bonding donor properties are significantly strengthened in solution. However, the bathochromic shift of the π→π* band leads to a partial overlap with the n→π* band, making it slightly more difficult to address. The introduction of iodine substituents is furthermore accompanied with a diminishing thermal half-life. A series of three azobenzenes with different halogen bonding donor properties are discussed in relation to their changing photophysical properties, rationalized by DFT calculations.


2018 ◽  
Vol 20 (33) ◽  
pp. 21515-21527 ◽  
Author(s):  
T. I. Burganov ◽  
S. A. Katsyuba ◽  
S. M. Sharipova ◽  
A. A. Kalinin ◽  
A. Monari ◽  
...  

The photophysical properties of a series of novel push–pull quinoxalinone-based chromophores that strongly absorb and emit light in the broad visible spectrum were comprehensively studied both experimentally and through quantum chemical methods.


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