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Carbazole is an important compound in pharmaceuticals and functional materials. A new Pd(II) supramolecular cage-catalyzed protocol for the synthesis of multifunctional carbazoles from indoles is described through regioselective successive oxidative Heck reactions. This new protocol is highly efficient, with a low Pd (2.4 mol%) catalyst loading and good compatibility for both N-H free and N-protected indole substrates. Moreover, it can be used to synthesize carbazoles with various functional groups by a one-pot two-step procedure. The excellent catalytic activity can be attributed to the distinct properties of the supramolecular cage structure in uniformly distributive and well-defined Pd(II) active centers on the cage surfaces.

On the basis of hard soft acid base theory, two neutral heterometallic M2Pd3 supramolecular cages, [Al2Pd3(L)6Cl6] (1) and [Fe2Pd3(L)6Cl6] (2) (where HL is 1-(4-(1H-imidazol-1-yl)phenyl)butane-1,3-dione), have been constructed by using the tripodal M(L)3 as metalloligands in combination with PdCl2 or Pd(MeCN)2Cl2. The supramolecular cage can be described as a trigonal bipyramid with two M3+ ions occupying at the two axial sites in ΔΔ or ΛΛ configurations and three Pd2+ ions sitting in the three equatorial positions with square planar geometry in trans configuration. The supramolecular cages exhibit high catalytic activity for the Suzuki–Miyaura coupling with arylbromide or arylchrolide and phenylboronic acid in biorenewable solvent glycerol under mild conditions. Moreover, the catalyst can be readily recycled and reused at least five times without loss of catalytic activity. The high catalytic performance may be attributed to the distinct properties of the cage structure with uniformly distributive and well-defined Pd active centres on the cage surfaces. The high stability in the cage structure also prevents Pd leaching out and agglomeration.

A series of porous MOFs with hendecahedron cage-liked cavity has been constructed from the [Cu2(COO)4] secondary building unit, H3L (H3L = [1,1';3',1'']Terphenyl-4,5',4''-tricarboxylic acid) and pyrazine derivatives varied with different sizes; the structural evolving of the hendecahedron cage and the application in drug delivery and controlled release were presented.

The Cu3(BTC)2 metal–organic framework (MOF) (BTC = 1,3,5-benzenetricarboxylate), also known as HKUST-1, is one of the earliest reported stable MOFs with a very high surface area. In this study, HKUST-1 was used for the first time to absorb the pharmaceutical products of ibuprofen, anethole and guaiacol with loading amount of 0.34 g·g− 1, 0.38 g·g− 1 and 0.40 g·g− 1, respectively, which also showing good controlled drug release property. The result from this work provides a new attempt for HKUST-1 to be used as potential platform for drug delivery and release.

A novel calcium based metal-organic framework (compound 1) was assembled from the connection of nano-sized {Ca11}SBU (2.36nm) and the triple-connective triangle aromatic acid, to give the formation of 3D MOF of 1 companied with a 2D porous structure with two 1D channel (size: 10.7A×10.8A and 9.4A×8.1A, respectively). The framework of 1 can afford a drug loading content of 0.19g/g of guaiacol and exhibited slow release effect toward guaiacol in 15h in PBS solution.Image 4

Solvothermal reaction assisted with microwave leads to the formation of two unique heterometallic cubic clusters [Ni{sub 3}M'(L){sub 3}(OH)(CH{sub 3}CN){sub 3}]{sub 2}.CH{sub 3}CN (M'=K for 1 and M'=Na for 2, where L is an anion of 2-[(2-hydroxy-3-methoxy-benzylidene)-amino]-ethanesulfonate) with higher efficiency, yields and purity than those without it. The 6-metallacrown-3 [Ni{sub 3}(OH)(L){sub 3}]{sup -} groups exhibit interesting ion trapping and self-assembly of size-different Na{sup +} and K{sup +} through form recognition and coordination activity in 1 and 2. The magnetic studies for 1 and 2 suggest that the {l_brace}Ni{sub 3}M'O{sub 4}{r_brace} (M'=K and Na) cores both display dominant ferromagnetic interactions from the nature of the binding modes of mu{sub 3}-O (oxidophenyl) and mu{sub 3}-OH. - Graphical abstract: Solvothermal reaction assisted with microwave leads to two heterometallic cubic clusters with 6-metallacrown-3 structure [Ni{sub 3}O{sub 3}(OH)]{sup -} acting as a host for a K{sup +} or Na{sup +} ion. The {l_brace}Ni{sub 3}M'O{sub 4}{r_brace} (M'=K, Na) cores display dominant ferromagnetic interactions.

[Pb2(boa)(Hbbp)2] has been synthesized by treating 4-carboxylphenoxyacetic (H2boa) and 2,6-bis(benzimidazolyl)pyridine (H2bbp) with metal salts under hydrothermal conditions. Adjacent metal centers forms dinuclear metal complex through carboxylato groups as building blocks. The arrangement of the half deprotonated H2bbp ligand and carboxylate groups exhibits a coordination gap around the Pb(II) ion, occupied possibly by a stereoactive lone pair of electrons on Pb(II), with the coordination environment around the lead atoms is hemidirected. This system is a particularly clear example that coordination sphere of a unique dinuclear Pb(II) compound was controlled by lone pair activity, weak Pb···O interactions, π–π stacking and the hydrogen bonds. The above weak interactions influence differently strong red-shifted effect about the solution and solid-state photoluminescence of the compound, compared to the free ligand.