To obtain stable and ultrafine Pt nanoclusters, a trigonal prismatic coordination cage with the sulfur atoms on the edges was solvothermally synthesized to confine them. In the structure of {Ni(TC4A-SO)(TDC) (HO)} (HTC4A-SO = p-tert-butylsulfonylcalix[4]arene; HTDC = 2,5-thiophenedicarboxylic acid), three Ni-(TC4A-SO) SBUs are bridged by three TDC ligands into a triangle and two such triangles are pillared by three pairs of TDC ligands to form a trigonal prism. The cage cavity has 12 sulfur atoms on the surface. Because of the porous structure and strong covalent interaction between metal and sulfur, ultrafine Pt nanoclusters composed of less than ∼18 Pt atoms can be facilely confined in the present trigonal prismatic cage (Pt@CIAC-121). The as-synthesized Pt NCs exhibit higher electrocatalytic activity than commercial Pt/C toward hydrogen evolution reaction.

We report a Johnson hexadecahedronal coordination cage, constructed via 10 Ni4-p-tert-butylthiacalix[4]arene (Ni4-TC4A) units as vertices and 16 5-(pyridin-4-yl)isophthalate (PIP) ligands as tiles. It features a gyroelongated square bipyramidal geometry, equivalent to two square pyramids pillared by a square antiprism, a J17 Johnson solid. Remarkably, the cage compound exhibits a much higher uptake capacity of C3H8 than CH4, representing a promising material for separation of these two gases. In contrast, Co4-TC4A units are linked by PIP ligands and rare {Co4O4Cl2} clusters, providing a one-dimensional bamboo stick-like polymer.

Catalyst plays a very important role in the exploration of new energy. To obtain a highly efficient electrocatalyst for the glucose oxidation and tiny metal nanocluster catalysts, a calixarene-based {Ni} coordination wheel with sulfur atoms on the cavity surface was designed, synthesized, and used as the porous template. Contributing from the active sites of nickel cations, the as-synthesized coordination wheels can efficiently catalyze the electrochemical oxidation of glucose with the onset and peak potentials of 0.3 and 0.46 V in alkaline medium, and the catalysis does not depend on the atmosphere (N, air, or O), which indicates that the coordination wheel will be a promising electrocatalyst candidate for the compartmentless glucose-air fuel cell. Meanwhile, benefiting from its confined cavity and inner sulfur surface, such a coordination wheel can serve as a general template for the fabrication and encapsulation of tiny metal nanoclusters of Au, Pd, Ir, Ru, Rh, Pt, and AuPd. In electrochemical examinations, the bimetallic AuPd clusters confined in the coordination wheel show higher current density than commercial Pt/C toward hydrogen evolution reaction (HER). The present study shows that the designed coordination wheel can be used as not only a type of novel catalyst itself but also a class of templates for metal cluster catalysts.

A novel coordination nanocage was obtained with in situ-generated tetrazole ligands from the cobalt-thiacalix[4]arene system. Four in situ-generated 1,3-bis(2H-tetrazol-5-yl)benzene ligands bolster eight Co4-calix shuttle-cock-like secondary building units (SBUs) into a hollow tetragonal prism with a high surface area. The unprecedented {Co32} nanocage presents the highest nuclearity example.

Supramolecular coordination complexes (SCCs) have been investigated extensively as the catalysts. Herein, we synthesize a calixarene-based {Co26} SCC (CIAC-126) for this purpose, which is constructed by 6 shuttlecock-like Co3-TC4A secondary building units, 1 Co8 cubic cluster, and 12 bridging imidazole-4,5-dicarboxylic ligands. CIAC-126 is featured with a three-piece burr puzzle in which each piece is perpendicular to the other two as the axes in a 3D Cartesian coordination system, leading to abundant edge defects. Electrocatalytic studies show that the composite of CIAC-126 and the commercial ordered mesoporous carbon (CMK-3), CIAC-126&CMK-3 (1:3, w/w), exhibits Pt-like electrocatalytic oxygen reduction activity in basic media due to the synergistic effect of the two components which provides both approachable active sites and electrical conductivity. It has higher stability than the commercial Pt/C catalyst, and there is almost no change in the oxygen reduction reaction (ORR) polarization curve after 3000 cycles. Furthermore, the nickel precursor instead of the cobalt feed leads to the formation of an open icosahedral {Ni36} coordination cage (CIAC-127) which displays modest ORR activity.

A metal-organic nanotube (MONT) was assembled by bridging the truncated metal-calixarene octahedra with coordinating water molecules. Remarkably, the tubular compound exhibited a much higher sorption capacity for CH and CH than for CH, and hence represents a promising material for separating these gases. The addition of a little NiSO into the reaction system led to the formation of a 2D metal-calixarene network.

Ultrafine metal nanoparticles (MNPs) with size <2 nm are of great interest due to their superior catalytic capabilities. Herein, we report the size-controlled synthesis of gold nanoparticles (Au NPs) by...

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