Post‐synthetic modification (PSM) is an effective approach for the tailored functionalization of metal‐organic architectures, but its generalizability remains challenging. Herein we report a general ...covalent PSM strategy to functionalize PdnL2n metal‐organic cages (MOCs, n=2, 12) through an efficient Diels–Alder cycloaddition between peripheral anthracene substituents and various functional motifs bearing a maleimide group. As expected, the solubility of functionalized Pd12L24 in common solvents can be greatly improved. Interestingly, concentration‐dependent circular dichroism and aggregation‐induced emission are achieved with chiral binaphthol (BINOL)‐ and tetraphenylethylene‐modified Pd12L24, respectively. Furthermore, Pd12L24 can be introduced with two different functional groups (e.g., chiral BINOL and achiral pyrene) through a step‐by‐step PSM route to obtain chirality‐induced circularly polarized luminescence. Moreover, similar results are readily observed with a smaller Pd2L4 system.
Two PdnL2n (n=2, 12) type metal‐organic cages (MOCs) decorated with anthracene groups have been successfully functionalized by a covalent post‐synthetic modification (PSM) approach. This has led to the modified MOCs having new functions compared to the parent MOCs (e.g., concentration‐dependent chirality, aggregation‐induced emission, and chirality‐induced circularly polarized luminescence).
The development of energy‐saving technology for the efficient separation of olefin and paraffin is highly important for the chemical industry. Herein, we report a self‐assembled Fe4L6 capsule ...containing a hydrophobic cavity, which can be used to encapsulate and separate propylene/propane. The successful encapsulation of propylene and propane by the Fe4L6 cage in a water solution was documented by NMR spectroscopy. The binding constants K for the Fe4L6 cage toward propylene and propane were determined to be (5.0±0.1)×103 M−1 and (2.1±0.7)×104 M−1 in D2O at 25 °C, respectively. Experiments and theoretical studies revealed that the cage exhibited multiple weak interactions with propylene and propane. The polymer‐grade propylene (>99.5 %) can be obtained from a mixture of propylene and propane by using the Fe4L6 cage as a separation material in a U‐shaped glass tube. This work provides a new strategy for the separation of olefin/paraffin.
A water‐soluble tetrahedral Fe4L6 metal‐organic cage has been successfully used to separate propane and propylene under ambient conditions. Mixed gases of C3H6 and C3H8 were captured by Fe4L6 at the gas‐liquid interface in a U‐shaped glass tube. Governed by the guest binding affinity, C3H6 is released first after transport of the gases to the receiving arm of the tube.
To develop a simple and general method for improving the circularly polarized luminescence (CPL) performances of materials is of great significance. In this work, two pairs of CPL‐active homochiral ...metal–organic frameworks (MOFs) P/M‐Et and P/M‐Et(Cd) with eta topology are reported. In comparison to the reported isomorphic Zn‐imidazolate MOFs P‐Me and M‐Me, both luminescence dissymmetry factor (glum) and photoluminescence quantum yields (ΦPL) of P‐Et and M‐Et are largely improved by simply changing the methyl group to an ethyl group of ligands in P‐Et and M‐Et. Furthermore, the |glum| values are significantly amplified up to 0.015 from 0.0057 by introducing the non‐luminescent halogenated aromatics, while an enhanced fluorescence efficiency is observed simultaneously (from 27.2% to 47.3%). The figure of merit value is about 40 times larger than that of P‐Me and M‐Me. Similarly, the CPL performances of P/M‐Et(Cd) are improved by about five times after encapsulating fluorobenzene molecules. This work represents a new and simple method for developing CPL‐active MOF materials.
Two pairs of circularly polarized luminescence (CPL)‐active homochiral metal–organic frameworks (MOFs) with eta topology are reported. Their CPL performances are highly boosted by introducing ethyl substituent groups and non‐luminescent halogenated aromatics guests, and the figure of merit value is about 40 times larger than that of the chiral MOFs with methyl substituent groups.
The development of circularly polarized luminescence (CPL) materials with high performance is significantly important. Herein, we develop a facial strategy for fabricating a CPL-active system by ...employing an achiral luminescent metal-organic cage (MOC) and chiral boron dipyrromethene (BODIPY) molecules. CPL is achieved by taking advantage of the radiative energy transfer process, in which BODIPY molecules act as energy acceptors and MOCs act as donors. The CPL performance (maximum luminescence dissymmetry factor up to ±1.5×10−3) can be tuned by adjusting the ratio between MOCs and BODIPY. White-light emission with the CPL feature is obtained by using a ternary system including MOC, chiral BODIPY, and Rhodamine B. The present work provides a facile and universal strategy to construct a CPL-active system by integrating achiral luminophores and chiral molecules.
The achiral metal-organic cage successfully achieves circularly polarized emission through radiative energy transfer. This strategy can break through the difficulty of chirality transfer in traditional materials, providing a facile and universal approach for the construction of CPL-active systems. Display omitted
The design and synthesis of artificial molecular containers for the encapsulation of hydrocarbon gases to study their host-guest chemistry are highly important for potential application in gas ...storage, separation, and understanding of their biological functions. In this work, we report the subcomponent self-assembly of four cubic Zn
8
L
12
Br
4
(HL =
N
-(4-
R
)-1-(5-methyl-1H-imidazole-4-yl)methanimine) cages with good solubility in chloroform, which are capable of binding hydrocarbon gases including methane, ethane, and ethene in solution at ambient temperature. Two types of gas binding sites (one is in the cavity, and the other is at the window) are discovered in these cages, which are documented by nuclear magnetic resonance (NMR) spectra and density functional theory (DFT) calculations. Their performance of encapsulation of hydrocarbon gases can be tuned by carefully adjusting substituent groups. These metal-organic cages containing two types of binding sites provide new artificial models to mimic the structures and functions of biological systems in binding and transforming hydrocarbon gases.
The development of energy‐saving technology for the efficient separation of olefin and paraffin is highly important for the chemical industry. Herein, we report a self‐assembled Fe4L6 capsule ...containing a hydrophobic cavity, which can be used to encapsulate and separate propylene/propane. The successful encapsulation of propylene and propane by the Fe4L6 cage in a water solution was documented by NMR spectroscopy. The binding constants K for the Fe4L6 cage toward propylene and propane were determined to be (5.0±0.1)×103 M−1 and (2.1±0.7)×104 M−1 in D2O at 25 °C, respectively. Experiments and theoretical studies revealed that the cage exhibited multiple weak interactions with propylene and propane. The polymer‐grade propylene (>99.5 %) can be obtained from a mixture of propylene and propane by using the Fe4L6 cage as a separation material in a U‐shaped glass tube. This work provides a new strategy for the separation of olefin/paraffin.
A water‐soluble tetrahedral Fe4L6 metal‐organic cage has been successfully used to separate propane and propylene under ambient conditions. Mixed gases of C3H6 and C3H8 were captured by Fe4L6 at the gas‐liquid interface in a U‐shaped glass tube. Governed by the guest binding affinity, C3H6 is released first after transport of the gases to the receiving arm of the tube.
Post‐synthetic modification (PSM) is an effective approach for the tailored functionalization of metal‐organic architectures, but its generalizability remains challenging. Herein we report a general ...covalent PSM strategy to functionalize PdnL2n metal‐organic cages (MOCs, n=2, 12) through an efficient Diels–Alder cycloaddition between peripheral anthracene substituents and various functional motifs bearing a maleimide group. As expected, the solubility of functionalized Pd12L24 in common solvents can be greatly improved. Interestingly, concentration‐dependent circular dichroism and aggregation‐induced emission are achieved with chiral binaphthol (BINOL)‐ and tetraphenylethylene‐modified Pd12L24, respectively. Furthermore, Pd12L24 can be introduced with two different functional groups (e.g., chiral BINOL and achiral pyrene) through a step‐by‐step PSM route to obtain chirality‐induced circularly polarized luminescence. Moreover, similar results are readily observed with a smaller Pd2L4 system.
Two PdnL2n (n=2, 12) type metal‐organic cages (MOCs) decorated with anthracene groups have been successfully functionalized by a covalent post‐synthetic modification (PSM) approach. This has led to the modified MOCs having new functions compared to the parent MOCs (e.g., concentration‐dependent chirality, aggregation‐induced emission, and chirality‐induced circularly polarized luminescence).
Abstract
Post‐synthetic modification (PSM) is an effective approach for the tailored functionalization of metal‐organic architectures, but its generalizability remains challenging. Herein we report a ...general covalent PSM strategy to functionalize Pd
n
L
2
n
metal‐organic cages (MOCs,
n
=2, 12) through an efficient Diels–Alder cycloaddition between peripheral anthracene substituents and various functional motifs bearing a maleimide group. As expected, the solubility of functionalized Pd
12
L
24
in common solvents can be greatly improved. Interestingly, concentration‐dependent circular dichroism and aggregation‐induced emission are achieved with chiral binaphthol (BINOL)‐ and tetraphenylethylene‐modified Pd
12
L
24
, respectively. Furthermore, Pd
12
L
24
can be introduced with two different functional groups (e.g., chiral BINOL and achiral pyrene) through a step‐by‐step PSM route to obtain chirality‐induced circularly polarized luminescence. Moreover, similar results are readily observed with a smaller Pd
2
L
4
system.
Post-synthetic installation strategy is an effective approach to improve the functions of metal-organic frameworks (MOFs). Herein, a pair of chiral MOFs is successfully constructed through ...solvothermal subcomponent self-assembly and exhibit circularly polarized luminescence (CPL). These MOFs contain coordinatively unsaturated Zn sites and channels, which allow the installation of pyridyl-terminated pillars into the original structure. Such a post-synthetic installation process reinforces the MOFs’ rigidity and increases the photoluminescence quantum yields (PLQYs). Furthermore, the luminescence dissymmetry factors (glum) of these post-modified MOFs are amplified after installing the pillars. This work provides an appealing strategy for boosting the CPL performance of chiral MOFs.
A pair of chiral metal-organic frameworks (MOFs) are synthesized by subcomponent self-assembly with coordinatively unsaturated Zn sites and channels, which exhibit weak circularly polarized luminescence (CPL) signals. Such a structural feature allows the post-synthetic installation of pyridyl-terminated pillars to boost the CPL performance of these chiral MOFs, providing an appealing approach for developing CPL-active MOF materials. Display omitted
