The removal of C2H2 and C2H6 from C2H4 streams is of great significance for feedstock purification to produce polyethylene and other commodity chemicals but the simultaneous adsorption of C2H6 and ...C2H2 over C2H4 from a ternary mixture has never been realized. Herein, a robust metal–organic framework, TJT‐100, was designed and synthesized, which demonstrates remarkably selective adsorption of C2H2 and C2H6 over C2H4. Breakthrough experiments show that TJT‐100 can be used as an adsorbent for high‐performance purification of C2H4 from a ternary mixture of C2H2/C2H4/C2H6 (0.5:99:0.5) to afford a C2H4 purity greater than 99.997 %, beyond that required for ethylene polymerization. Computational studies reveal that the uncoordinated carboxylate oxygen atoms and coordinated water molecules pointing towards the pore can trap C2H2 and C2H6 through the formation of multiple C−H⋅⋅⋅O electrostatic interactions, while the corresponding C2H4–framework interaction is unfavorable.
A robust porous metal–organic framework was synthesized and utilized for the highly selective separation of C2H4 from a ternary mixture of C2 hydrocarbons. After a single operation, the C2H4 purity of the outlet was greater than 99.997 %.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Kinetically stable and long‐lived intermediates are crucial in monitoring the progress and understanding of supramolecular self‐assembly of diverse aggregated structures with collective functions. ...Herein, the complex dynamics of an atomically precise CuI nanocluster Cu8(tBuC6H4S)8(PPh3)4 (Cu8a) is systematically investigated. Remarkably, by monitoring the aggregation‐induced emission (AIE) and electron microscopy of the kinetically stable intermediates in real time, the directed self‐assembly (DSA) process of Cu8a is deduced. The polymorphism and different emission properties of Cu NCs aggregates were successfully captured, allowing the structure–optical property relationship to be established. More importantly, the utilization of a mathematical “permutation and combination” ideology by introducing a heterogeneous luminescent agent of a carbon dot (CD) to Cu8a aggregates enriches the “visualization” fluorescence window, which offers great potential in real time application for optical sensing of materials.
Within the scheme of aggregation‐induced emission (AIE), optical‐engineering was performed for real‐time monitoring of the self‐assembly process of Cu8a with various kinetic long‐lived intermediates, leading to a structure–property relationship being established.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
To conquer the bottleneck of sluggish kinetics in cathodic oxygen reduction reaction (ORR) of metal‐air batteries, catalysts with dual‐active centers have stood out. Here, a “pre‐division metal ...clusters” strategy is firstly conceived to fabricate a N,S‐dual doped honeycomb‐like carbon matrix inlaid with CoN4 sites and wrapped Co2P nanoclusters as dual‐active centers (Co2P/CoN4@NSC‐500). A crystalline {CoII2} coordination cluster divided by periphery second organic layers is well‐designed to realize delocalized dispersion before calcination. The optimal Co2P/CoN4@NSC‐500 executes excellent 4e− ORR activity surpassing the benchmark Pt/C. Theoretical calculation results reveal that the CoN4 sites and Co2P nanoclusters can synergistically quicken the formation of *OOH on Co sites. The rechargeable Zn‐air battery (ZAB) assembled by Co2P/CoN4@NSC‐500 delivers ultralong cycling stability over 1742 hours (3484 cycles) under 5 mA cm−2 and can light up a 2.4 V LED bulb for ≈264 hours, evidencing the promising practical application potentials in portable devices.
A “pre‐division metal clusters” strategy is first conceived to fabricate dual‐active center catalysts (Co2P/CoN4@NSC‐500) with dispersed CoN4 and Co2P sites. The optimal catalyst executes superior ORR activity and was applied in ultralong Zn‐air batteries surpassing the benchmark 20 % Pt/C. Theoretical calculations demonstrate that the dual‐active sites synergistically quicken the formation of the *OOH intermediate, greatly boosting the performance.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The structural transformations of metal nanoclusters are typically quite complex processes involving the formation and breakage of several bonds, and thus are challenging to study. Herein, we report ...a case where two lacunary Keggin polyoxometallate templated silver single-pods PW
O
@Ag
(SD/Ag51b) fuse to a double-pod (PW
O
)
@Ag
by reacting with 4,4'-bipyridine (bipy) or 1,4-bis(4-pyridinylmethyl)piperazine (pi-bipy). Their crystal structures reveal the formation of a 2D 4
-sql layer (SD/Ag72a) with bipy and a 3D pcu framework (SD/Ag72c) with pi-bipy. The PW
O
retains its structure during the cluster fusion and cluster-based network formation. Although the two processes, stripping of an Ag-ligands interface followed by fusion, and polymerization, are difficult to envisage, electrospray ionization mass spectrometry provides enough evidences for such a proposal to be made. Through this example, we expect the structural transformation to become a powerful method for synthesizing silver nanoclusters and their infinite networks, and to evolve from trial-and-error to rational.
A new family of 2D coordination polymers based on 3d‐4f 15‐metallacrown‐5 (MC) units were designed and characterized. The connection of the 15‐metallacrown‐5 subunits by the coordination of CuII and ...ligand led to the formation of 2D network of metallacrowns. Analysis of the magnetic properties of these coordination polymers reveals that the GdIII (1), TbIII (2), and DyIII (3) complexes exhibit slow magnetic relaxation and under 1000 Oe dc field, and the DyIII (3) complex exhibits single‐molecule magnet behavior.
A new family of 2D coordination polymers based on 3d‐4f 15‐metallacrown‐5 (MC) units was designed and characterized. The connection of the 15‐metallacrown‐5 subunits by the coordination of CuII and ligand led to the formation of 2D network of metallacrowns. The GdIII, TbIII, and DyIII complexes exhibit slow magnetic relaxation, and the DyIII complex is a single‐molecule magnet under 1000 Oe dc field.
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Constructing atomically precise helical superstructures of high order is an extensively pursued subject for unique aesthetic features and underlying applications. However, the construction of ...cluster-based helixes of well-defined architectures comes with a huge challenge owing to their intrinsic complexity in geometric structures and synthetic processes. Herein, we report a pair of unique
P-
and
M-
single stranded helical superstructures spontaneously assembled from
R
-
and
S
-Au8c
individual nanoclusters, respectively, upon selecting chiral BINAP (2,2′-bis(diphenylphosphino)-1,1′-binaphthalene) and hydrophilic
o
-H
2
MBA (
o
-mercaptobenzoic acid) as protective ligands to induce chirality and facilitate the formation of helixes. Structural analysis reveals that the chirality of the
Au8c
individual nanoclusters is derived from the homochiral ligands and the inherently chiral Au
8
metallic kernel, which was further corroborated by experimental and computational investigations. More importantly, driven by the O-H O interactions between (HCO
3
−
)
2
dimers and achiral
o
-HMBA
−
ligands,
R
/
S
-Au8c
individual nanoclusters can assemble into helical superstructures in a highly ordered crystal packing. Electrospray ionization (ESI) and collision-induced dissociation (CID) mass spectrometry of
Au8c
confirm the hydrogen-bonded dimer of
Au8c
individual nanoclusters in solution, illustrating that the insertion of (HCO
3
−
)
2
dimers plays a crucial role in the assembly of helical superstructures in the crystalline state. This work not only demonstrates an effective strategy to construct cluster-based helical superstructures at the atomic level, but also provides visual and reliable experimental evidence for understanding the formation mechanism of helical superstructures.
A pair of unprecedented helical superstructures
via
self-assembly of inherently homochiral Au
8
nanoclusters, Au
8
(
R
/
S
-BINAP)
3
(
o
-HMBA)
2
·2(HCO
3
), is obtained in the crystalline state, in which the HCO
3
−
ions act as the bridge.
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Three rare isostructural heterometallic complexes Na2{Ln4(μ3‐OH)2(ppt)4(Hppt)2(OAc)2}(DMF)4 ⋅ xH2O (H2ppt=3‐(2‐hydroxyphenyl)‐5‐(pyrazin‐2‐yl)‐1,2,4‐triazole, x=2.5, Ln=Dy (1); x=2, Ln=Er (2); x=0, ...Ln=Yb (3)) have been obtained. The structural analysis displayed that two NaI and four LnIII ions were linked together through N−N groups and O atoms to form a metallmacrocycle with the connectivity pattern Dy−O−Na−N−N−Dy−O2. Such cases possess rare hexametallic ring, which further displays one tetrametallic and two trimetallic cyclic units. Magnetic measurements reveal single‐molecule magnet (SMM) behavior for 1 with the effective energy barrier of 51.6 K and pre‐exponential factor of 6.16×10−6 s deduced from frequency‐dependent magnetic susceptibilities. Ab initio calculations prove that the weak ferromagnetic coupling mainly originats from the dipolar interaction. The transversal magnetic moments in the ground Kramers could suppressed the quantum tunneling of magnetization.
Three rare heterometallic azametallacrowns(azaMCs) with aza14‐MC‐6 and aza10‐MC‐4 structural motifs have been reported. 1 exhibits intramolecular weak ferromagnetic coupling and single molecule magnet behavior. The fitting of frequency‐dependent susceptibility data reveals the effective energy barrier Ueff of 35.83 K and time constant τ0 of 6.16×10−6 s.
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Exploration of cost-efficient and high-performance photocatalyst for H2 evolution by using a facile approach is of great importance. In this manuscript, a facile one-pot method was employed to ...fabricate MoS2/CdS heterostructures with MoS2 intimately grown on the surface of CdS resulting in the formation of well-defined heterostructures. Screen experiment reveals the optimized photocatalytic H2 evolution performance of MoS2/CdS is far exceeding that of pristine CdS by a factor of more than 162. The outstanding performance can be ascribed to the formation of heterostructures which accelerate charge transportation and separation, and the MoS2 serving as a cocatalyst for the decrease of H2 overpotential. Moreover, the photocatalytic mechanism of the MoS2/CdS was carefully investigated, which contributes to the deep understanding of the photocatalytic process and the designation of other low-cost and high-efficient photocatalyst.
Display omitted
•The MoS2/CdS nanoheterostructures were synthesized by using one-pot approach.•The H2 evolution rate of MoS2/CdS is 162 times higher than that of pristine CdS.•The extraordinary performance is attributed to the well-defined heterostructures.•The photocatalytic mechanism was detailedly investigated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The luminescence sensor is one of the most effective devices for monitoring environmental pollution. By combining precise structures and defined functional sites, luminescent coordinated metal ...clusters (LCMCs) can allow mechanism-based luminescence sensing optimization. Here, a
{Zn
4
}
cluster has been fabricated by introducing uncoordinated N-, OH-dual hydrogen-bonding active sites as well as coordination of unsaturated Zn
II
sites. As expected, the
{Zn
4
}
cluster displays high selectivity and sensitivity for sensing Cl
−
with low detection limits (LODs) in pure water (0.94 μM), HEPES biological buffer (1.44 μM), and real river water media (1.36 μM) by luminescent enhancement which are much lower than the minimum standards of drinking water enacted by the World Health Organization (WHO) and U.S. Environmental Protection Agency (USEPA) (7.05 mM). Additionally, the
{Zn
4
}
cluster is also sensitive to histidine with low LODs in both pure water (0.83 μM), HEPES biological buffer (4.87 μM) and real river water samples (1.18 μM) through the luminescent quenching effect. Luminous test papers of the
{Zn
4
}
cluster are made to provide a convenient, quick and real-time naked eye detection effect for sensing Cl
−
and histidine. The luminescence sensing mechanism of Cl
−
is further revealed
via
integrating several experiments with density functional theory (DFT) calculations. The results indicate that the
{Zn
4
}
cluster is a promising material candidate for application in environmental monitoring.
A novel
{Zn
4
}
cluster can efficiently detect Cl
−
and histidine with low LODs in various aqueous media. The sensing mechanism of Cl
−
is revealed by various experimental methods and DFT calculations.
By changing the stoichiometric ratios, the one-pot reaction of the glycinehydroxamic acid (H
2
glyha) ligand with copper(
ii
) and lanthanide(
iii
) salts in the presence of diamagnetic Na
2
{Fe(CN)
...5
(NO)} led to two series of isostructural complexes, which can be designated as heterotrimetallic dimeric clusters {LnCu
5
(glyha)
5
}{Fe(CN)
5
(NO)}(H
2
O)
4
2
·
x
NO
3
·
y
H
2
O (
x
= 2,
y
= 11 for La (
1
),
x
= 2,
y
= 11 for Pr (
2
), and
x
= 2,
y
= 11 for Nd (
3
)) and heterotetrametallic coordination polymers Na{LnCu
5
(glyha)
5
}{Fe(CN)
5
(NO)}
2
(H
2
O)
x
·
y
H
2
O
n
(
x
= 6,
y
= 4 for Sm (
4
),
x
= 6,
y
= 0 for Gd (
5
),
x
= 6,
y
= 4 for Tb (
6
),
x
= 5,
y
= 5 Dy (
7
), and
x
= 6,
y
= 4 for Ho (
8
)). Each molecular structure contains Ln
III
15-metallacrown-5 nodes and diamagnetic Fe(CN)
5
(NO)
2−
linkers. The resulting products demonstrate diversified structural frameworks due to the radius effect of Ln
III
ions and different bridging fashions of diamagnetic Fe(CN)
5
(NO)
2−
linkers. An analysis of magnetic susceptibilities reveals that
7
exhibits ferromagnetic coupling between Cu
II
and Dy
III
ions and field-induced SMM behavior.
Two families of metallacrown complexes have been obtained by one-pot procedure. The different radii of Ln ions and the binding fashions of diamagnetic linkers result in diversified structural frameworks.
