With H2 O or NH3 stimuli, the blue cobalt-based metal-organic framework (MOF) BP can reversibly transform to red RP. The removal/recovery of terephthalate ligands accompanied by the transformation leads to a gate effect, which allows the encapsulation and release of small solvent molecules under certain conditions. This is the first example of topology transformation from a self-penetrating to interpenetrating net in 3D MOFs.

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In this work, BEA-type hierarchically structured stannosilicate zeolite Sn-Beta-H was developed, which involved alkali-induced degradation of all-silica Beta (Si-Beta) and self-assembly of the resultant Si-Beta fragments with SnCl2·2H2O in the hydrothermal condition templated with tetraethylammonium hydroxide (TEAOH) and polydiallydimethylammonium chloride (PDADMAC). The synthesized Sn-Beta-H zeolite was comprehensively characterized by means of XRD, N2 physisorption, TEM, UV–vis, XPS, TG, DRIFT, and FTIR spectroscopy with pyridine and deuterated acetonitrile adsorption. The Lewis acidity related to isolated tetrahedrally coordinated Sn species in the hierarchical porous Beta framework was revealed, which existed in the form of partially hydrolyzed and framework-integrated species. The Sn-Beta-H zeolite worked efficiently in the catalytic transformation of a series of carbohydrates into methyl lactate, outperforming the microporous Sn-Beta and postsynthesized mesoporous meso-Sn-Beta counterparts. The influence parameters such as mesoporosity, hydrophilicity/hydrophobicity, and Lewis acidity on the glucose conversion were studied in detail.

Seven new metal complexes with the formulas, [ Zn 2 (L 1 ) 2 (H 2 O)] n (1), [Cd 2 (L 1 )Cl 2 (H 2 O)] n (2), [Cd 3 (L 1 ) 3 (H 2 O) 12 ] and {[Cd 3 (L 3 ) 2 Cl 4 ] • (H 2 O) 4 } n (7), have been synthesized by the reactions of Zn II or Cd II salts with three structurally related flexible bis (tetrazol-5-yl) alkanes, 1,2-bis(tetrazol-5-yl)ethane (H 2 L 1 ), 1,3-bis(tetrazol-5-yl)propane (H 2 L 2 ), and 1,4-bis(tetrazol-5-yl)butane (H 2 L 3 ), and characterized by single crystal X-ray diffraction analysis, IR spectroscopy, and thermogravimetric (TG) analysis. Because of the geometrical requirements of different metal ions and the diverse coordination modes of the tetrazolate rings of flexible bis(tetrazole) ligands as well as the different reaction conditions, the obtained complexes show diverse structures from one-dimensional (1D) chain to three-dimensional (3D) coordination polymers. 1, 4, and 6 are Zn II complexes in which the Zn II ions show tetrahedral coordination geometries. 1 and 4 are 3D frameworks, while 6 is 1D chain structure. 2, 3, 5, and 7 are Cd II complexes, and the Cd II ions show octahedral coordination geometries. 3 is a twodimensional (2D) sheet and 2, 5, 7 are all 3D frameworks. The tetrazolate rings of the structurally related ligands adopt either µ 1 -tetrazolyl, µ 2 -tetrazolyl, µ 3 -tetrazolyl, or µ 4 -tetrazolyl modes in our obtained complexes. The fluorescent properties of these complexes have also been investigated in the solid state at room temperature.

Aiming at tuning the adsorption and fluorescence properties of targeted porous organic polymer, four new aminal-linked porous organic polymers (NAPOPs) were synthesized through the reaction of 1,4-Bis(4,6-diamino-s-triazin-2-yl) benzene (BATB) with four kinds of aldehydes substituted with different N-heterocyclic groups. Among the polymers, NAPOP-3 decorated with 5-phenyl-tetrazole group shows the largest CO 2 adsorption capacity (2.52 mmol g 21 at 273 K and 100 kPa) because of its relative large surface area, while NAPOP-1 decorated with piperazine groups shows relative large CO 2 /N 2 adsorption selectivity (77 at 273 K and 100 kPa), attributable to its large CO 2 adsorption heats and cabined pore (<4 Å ). Meanwhile, NAPOP-1 and 23 exhibit high adsorption rate toward iodine with a high capacity (>240 wt %). In addition, different luminescence emissions were also observed for NAPOPs, indicating different intramolecular charger transfer occurred inside polymer networks.

A new chemosensor, 2,3,15,16-tetrakis(pyridin-2-yl)-7,8,10,11,20,21,23,24-octahydro[1,4,7,10,13,16]hexaoxacyclooctadecino[2,3-g:11,12-g']diquinoxaline (1), containing 2,3-bis(pyridin-2-yl)quinoxaline and crown ether moieties, has been designed and found to be a ratiometric and selective fluorescent detector of Zn(2+) over a wide range of tested metal ions. The addition of Zn(2+) to the solution of 1 in acetonitrile induced the formation of a 1:2 ligand-metal complex, 1-Zn(2+), which exhibits a remarkable enhanced fluorescent emission centered at 460 nm, with the disappearance of the fluorescent emission of 1 centered at 396 nm due to the mechanism of internal charge transfer. In contrast, the presence of K(+) results in the fluorescence quenching of 1 and 1-Zn(2+) through the photoinduced electron-transfer mechanism. These results demonstrate that 1 can perform as not only an INHIBIT logic gate but also an "off-on-off" molecular switch triggered by Zn(2+) and K(+). The structure of complex 1-Zn(2+) has been characterized by single-crystal X-ray crystallography, mass spectrometry, and (1)H NMR titration experiments. Density functional theory calculation results on 1 and the 1-Zn(2+) complex are well consistent with the experimental results.

In our continuing efforts to explore the effects of ligand modifications on the structures and properties of their metal complexes, we studied the in situ [2 + 3] cycloaddition reactions of benzonitrile, o-phthalodinitrile, 3-cyanobenzoic acid, 4-cyanobenzoic acid with NaN(3) in the presence of Zn(II) and/or Co(II) salts under hydrothermal conditions, and obtained four new Co(II)-doped Zn(II)-tetrazole-benzoate coordination polymers with the formula of [Co(x)Zn(1-x)(L(m))(y)](n) [5-phenyl-1H-tetrazole (HL(1)) for 1, 2-(1H-tetrazol-5-yl)benzoic acid (H(2)L(2)) for 2, 3-(1H-tetrazol-5-yl)benzoic acid (H(2)L(3)) for 3, and 4-(1H-tetrazol-5-yl)benzoic acid (H(2)L(4)) for 4]. The structure of 1 shows a classical diamondoid net, while 2 and 3, take 2D layer structure with (4.6(2))(4.6.4.6) topology and 3D SrAl(2) topology, respectively. The structure of 4 exhibits a four-connected 3D network with rare non-diamondoid 6(6) topology. The coordination modes of the center metal and the ligands in the four complexes are almost the same, being tetrahedral or four-connected, but their topologies are quite different. Thus, the four structurally related ligands allow analysis of the effects of the disposition of a second functional carboxylate group on an aromatic ring and the twist angles of the carboxylate and tetrazoyl out of the plane of the aromatic ring on the overall structural topology of their complexes. Interestingly, the Co(II) ions were doped into the Zn(II) complexes, as confirmed by their macroscopical colors, inductively coupled plasma (ICP) analysis and UV-visible spectra. In addition, the photoluminescence of the four complexes in the solid state at room temperature was briefly studied.

FAU-type hafnosilicate zeolite with a hierarchical structure (Hf-USY) was constructed through a post-synthesis strategy containing the controlled dealumination of the commercial H-USY zeolite and the subsequent dry impregnation of the Cp 2 HfCl 2 precursor. The incorporation of Hf ions into the zeolite framework involved the interaction between the silanol groups from framework dealumination and Cp 2 HfCl 2 molecules. Characterization results from UV−vis and X-ray photoelectron spectroscopy verified that the incorporated Hf ions mainly existed in the tetrahedrally coordinated form in the zeolite framework. The creation of Lewis acid sites associated with Hf incorporation was confirmed by Fourier transform infrared spectroscopy with pyridine and deuterated acetonitrile adsorption. The as-synthesized Hf-USY zeolite served as a highly efficient catalyst in the transfer hydrogenation of ethyl levulinate to γvalerolactone, outperforming the Sn-and Zr-silicate analogues. The Hf-USY catalyst also exhibited good performance in the transfer hydrogenation of more challenging substrates such as furanic, aromatic, as well as alkene-substituted carbonyl compounds into the corresponding alcohols. The influence of Lewis acid sites, preparation parameters, as well as the hydrogen donor on the catalytic activity of the Hf-USY zeolite was investigated in detail.