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Developing hierarchical ordered systems is challenging. Using organo-macrocycles to construct metal–organic frameworks (MOFs) and porous coordination cages (PCCs) provides an efficient way to obtain hierarchical assemblies. Macrocycles, such as crown ethers, cyclodextrins, calixarenes, cucurbiturils, and pillararenes, can be incorporated within MOFs/PCCs and they also endow the resultant composites with enhanced properties and functionalities. This review summarizes recent developments of organo-macrocycle-containing hierarchical MOFs/PCCs, emphasizing applications and structure–property relationships of these hierarchically porous materials. This review provides insights for future research on hierarchical self-assembly using macrocycles as building blocks and functional ligands to extend the applications of the composites. [ABSTRACT FROM AUTHOR]

Surface organic ligands are critical in dictating the structures and properties of atomically precise metal nanoclusters. In contrast to the conventionally used thiolate, phosphine and alkynyl ligands, nitrogen donor ligands have not been used in the protection for well‐defined metal nanoclusters until recently. This review focuses on recent developments in atomically precise metal nanoclusters stabilized by different types of nitrogen donor ligands, in which the synthesis, total structure determination and various properties are covered. We hope that this review will provide insights into the rational design of N donor‐protected metal nanoclusters in terms of structural and functional modulation. [ABSTRACT FROM AUTHOR]

By directly reducing alkynyl–silver precursors, we successfully obtained a large alkynyl‐protected silver nanocluster, (C7H17ClN)3[Ag112Cl6(C≡CAr)51], which is hitherto the largest structurally characterized silver nanocluster in the alkynyl family. The cluster exhibits four concentric core–shell structures (Ag13@Ag42@Ag48@Ag9), and four types of alkynyl–silver binding modes are observed. Chloride was found to be critical for the stabilization and formation of the silver nanocluster. The release of chloride ions in situ from CH2Cl2 solvent has been confirmed by mass spectrometry. This study suggests that the combination of alkynyl and halide ligands will pave a new way for the synthesis of large silver nanoclusters. [ABSTRACT FROM AUTHOR]

Two homoleptic alkynyl‐protected gold clusters with compositions of Na[Au25(C≡CAr)18] and (Ph4P)[Au25(C≡CAr)18] (Na⋅1 and Ph4P⋅1, Ar=3,5‐bis(trifluoromethyl)phenyl) were synthesized via a direct reduction method. 1 is a magic cluster analogous to [Au25(SR)18]− in terms of electron counts and metal‐to‐ligand ratio. Single‐crystal structure analysis reveals that 1 has an identical Au13 kernel to [Au25(SR)18]−, but adopts a distinctly different arrangement of the six peripheral dimer staple motifs. The steric hindrance of alkynyl ligands is responsible for the D3 arrangement of Au25. The introduction of alkynyl also significantly changes the optical absorption features of the nanocluster as supported by DFT calculations. This magic cluster confirms that there is a similar but quite different parallel alkynyl‐protected metal cluster universe in comparison to the thiolated one. Magic clusters Na[Au25(C≡CAr)18] and (Ph4P)[Au25(C≡CAr)18] (Ar=3,5‐bis(trifluoromethyl)phenyl) exhibit novel connection between staples and the Au13 core. Steric hindrance caused by rigid ligand coordination preference accounts for the different geometric and electronic structures. [ABSTRACT FROM AUTHOR]

For the first time total structure determination of homoleptic alkynyl-protected gold nanoclusters is reported. The nanoclusters are synthesized by direct reduction of PhC≡CAu, to give Au44(PhC≡C)28 and Au36(PhC≡C)24. The Au44 and Au36 nanoclusters have fcc-type Au36 and Au28 kernels, respectively, as well as surrounding PhC≡C-Au-C2(Ph)Au-C≡CPh dimeric 'staples' and simple PhC≡C bridges. The structures of Au44(PhC≡C)28 and Au36(PhC≡C)24 are similar to Au44(SR)28 and Au36(SR)24, but the UV/Vis spectra are different. The protecting ligands influence the electronic structures of nanoclusters significantly. The synthesis of these two alkynyl-protected gold nanoclusters indicates that a series of gold nanoclusters in the general formula Au x(RC≡C) y as counterparts to Au x(SR) y can be expected. [ABSTRACT FROM AUTHOR]

For the first time total structure determination of homoleptic alkynyl-protected gold nanoclusters is reported. The nanoclusters are synthesized by direct reduction of PhC≡CAu, to give Au44(PhC≡C)28 and Au36(PhC≡C)24. The Au44 and Au36 nanoclusters have fcc-type Au36 and Au28 kernels, respectively, as well as surrounding PhC≡C-Au-C2(Ph)Au-C≡CPh dimeric 'staples' and simple PhC≡C bridges. The structures of Au44(PhC≡C)28 and Au36(PhC≡C)24 are similar to Au44(SR)28 and Au36(SR)24, but the UV/Vis spectra are different. The protecting ligands influence the electronic structures of nanoclusters significantly. The synthesis of these two alkynyl-protected gold nanoclusters indicates that a series of gold nanoclusters in the general formula Au x(RC≡C) y as counterparts to Au x(SR) y can be expected. [ABSTRACT FROM AUTHOR]

An intensely luminescent gold(I)-silver(I) cluster [(C)(AuPPhpy2)6Ag6(CF3CO2)3](BF4)5 (PPhpy2=bis(2-pyridyl)phenylphosphine) ( 3) is synthesized by the reaction of [(C)(AuPPhpy2)6Ag4](BF4)6 with AgCF3CO2. All eight faces of the octahedral C@Au6 core in 3 are capped, that is, six faces are capped by silver ions and two by tetrafluoroborates. Cluster 3 is intensely luminescent in solution with a quantum yield of 92 %. Ligation of CF3CO2− ions is vital for the construction and emission properties of 3, as confirmed by DFT calculations. BF4− ions are involved in the protecting sphere of the metal core, as evidenced by 19F NMR data. The participation of phosphines, CF3CO2−, and BF4− ions in the protection of the emissive core and the enhancement of the rigidity of the cluster result in the high emission efficiency. This is the first example of organic ligands and inorganic anions forming a rigid protecting sphere for luminescent coinage-metal clusters. [ABSTRACT FROM AUTHOR]

A red-near-IR dual-emissive nanocluster with the composition [Au10Ag2(2-py−C≡C)3(dppy)6](BF4)5 ( 1; 2-py−C≡C is 2-pyridylethynyl, dppy=2-pyridyldiphenylphosphine) has been synthesized. Single-crystal X-ray structural analysis reveals that 1 has a trigonal bipyramidal Au10Ag2 core that contains a planar Au4(2-py−C≡C)3 unit sandwiched by two Au3Ag(dppy)3 motifs. Cluster 1 shows intense red-NIR dual emission in solution. The visible emission originates from metal-to-ligand charge transfer (MLCT) from silver atoms to phosphine ligands in the Au3Ag(dppy)3 motifs, and the intense NIR emission is associated with the participation of 2-pyridylethynyl in the frontier orbitals of the cluster, which is confirmed by a time-dependent density functional theory (TD-DFT) calculation. [ABSTRACT FROM AUTHOR]

A convenient method for the synthesis of silver alkynyl compounds containing different nuclearities has been developed. The reaction of AgC≡CBut and AgX (X = CF3CO2−, C2F5CO2−) in the presence of auxiliary ligands L (L = bipyridine, bipy; 1,10-phenanthroline, phen; 2-(diphenylphosphino)pyridine, dppy) under different conditions afforded a family of new silver alkynyl compounds, namely, [Ag3(bipy)(C≡CBut)(CF3CO2)2]n (1), [Ag4(bipy)2(C≡CBut)(CF3CO2)3]n (2), [Ag6(phen)3(C≡CBut)2(C2F5CO2)4(MeOH)(EtOH)] (3), [Ag8L4(C≡CBut)2(C2F5CO2)6] (L = bipy, 4; L = phen, 5), [Ag10(dppy)2(C≡CBut)6X4] (X = CF3CO2−, 6; X = C2F5CO2−, 7), [Ag12(bipy)2(C≡CBut)8(C2F5CO2)4] (8) and [Ag12(phen)4(C≡CBut)6(CF3CO2)6]·2EtOH (9). Single-crystal X-ray analysis revealed that compounds 1 and 2 display infinite-chain structures, while the other seven compounds are discrete molecules containing silver nuclearities varying from 6 to 12. The formation of various structural motifs depends on the reactant ratios and the ligands/anions with different nature. [ABSTRACT FROM AUTHOR]

The Frontispiece shows two nanoclusters are induced by the change of the surface alkynyl structures. The alkynyl −C≡C−tBu gives rise to a more spherical surface shape in 1 (red background) while −C≡CC6H4‐p‐tBu to a flat shape in 2 (green backgroud). The red and green also represent their different crystal colors and different UV/Vis properties. There are also Cl (green ball) and dppf (purple ball) surrounding these structures, suggesting co‐protection by three types of ligands. For more information, see the Full Paper Y.‐M. Lin, Q.‐M. Wang et al. on page 16029 ff. [ABSTRACT FROM AUTHOR]

The Frontispiece shows two nanoclusters are induced by the change of the surface alkynyl structures. The alkynyl −C≡C−tBu gives rise to a more spherical surface shape in 1 (red background) while −C≡CC6H4‐p‐tBu to a flat shape in 2 (green backgroud). The red and green also represent their different crystal colors and different UV/Vis properties. There are also Cl (green ball) and dppf (purple ball) surrounding these structures, suggesting co‐protection by three types of ligands. For more information, see the Full Paper Y.‐M. Lin, Q.‐M. Wang et al. on page 16029 ff. [ABSTRACT FROM AUTHOR]

By directly reducing alkynyl–silver precursors, we successfully obtained a large alkynyl‐protected silver nanocluster, (C7H17ClN)3[Ag112Cl6(C≡CAr)51], which is hitherto the largest structurally characterized silver nanocluster in the alkynyl family. The cluster exhibits four concentric core–shell structures (Ag13@Ag42@Ag48@Ag9), and four types of alkynyl–silver binding modes are observed. Chloride was found to be critical for the stabilization and formation of the silver nanocluster. The release of chloride ions in situ from CH2Cl2 solvent has been confirmed by mass spectrometry. This study suggests that the combination of alkynyl and halide ligands will pave a new way for the synthesis of large silver nanoclusters. [ABSTRACT FROM AUTHOR]

Small anions play a big role in the preparation of an intensely luminescent gold(I)–silver(I) cluster. In their Communication on page 7117 ff. Q.‐M. Wang and co‐workers show that the stepwise addition of silver ions to the gold‐cluster precursor enhances the rigidity of the cluster. The emissive core is fully protected by organic ligands and inorganic anions, which results in high emission efficiency. [ABSTRACT FROM AUTHOR]