Shengyu Feng

Bright-yellow to orange-red thermochromic luminescence of an AgI6–ZnII2 heterometallic aggregate

A novel octanuclear Ag(I)(6)-Zn(II)(2) heterometallic aggregate, (NH(4))(2){[Zn(2)(phen)(2)(H(2)O)(4)][Ag(6)(mna)(6)]}·2H(2)O·2CH(3)CH(2)OH (1, H(2)mna = 2-mercaptonicotinic acid, phen = 1,10-phenanthroline), was stepwisely obtained based on a hexanuclear silver(i) metalloligand using a liquid-liquid diffusion method. It is an exceedingly rare example that exhibits interesting temperature dependent photoluminescence behaviors, including gradual changes in energy and intensity upon cooling.

A 3D porous metal–organic framework constructed of 1D zigzag and helical chains exhibiting selective anion exchange

Slow diffusion of AgClO44 with Me2Si [(4-(Im-1-yl)Ph]2 (BIPS) yields the crystalline complex 1 with a 3D-braided porous metal–organic framework via self-assembly of two series of 1D polymer chains through both braiding and interpenetrating. Complex 1 consists of two distinct kinds of channels with different sizes and shapes along a and b directions occupied by perchlorate anions and water molecules.

Reactant ratio-modulated six new copper(I)–iodide coordination complexes based on diverse [CumIm] aggregates and biimidazole linkers: syntheses, structures and temperature-dependent luminescence properties

A total of six copper(I)–iodide coordination complexes with diverse [CumIm] aggregates and bidentate biimidazole bridging ligands, [Cu2I2(dmimb)]n (1), [Cu4I4(dmimb)]n (2), [Cu6I6(dmimb)3]n (3), [Cu4I4(dimb)]n (4), [Cu2I2(dimb)2]n (5), and [Cu4I4(dimb)3]n (6), (dmimb = 1,4-di(2-methyl-imidazol-1-yl)butane, dimb = 1,3-di(imidazol-1-yl)benzene), have been synthesized and structurally characterized by single-crystal X-ray diffraction analyses and further characterized by infrared spectra (IR), elemental analyses, powder X-ray diffraction (PXRD) and thermogravimetric analyses (TGA). Single-crystal X-ray diffraction analysis reveals that 1 is a double-chain based 1D ribbon incorporating a discrete [Cu4I4] stepped cubane aggregate. Complex 2 is a 2D layer based on the 1D infinite [Cu6I6]n column aggregate. Complex 3 is a triple-chain based 1D ribbon incorporating a discrete ladder-like [Cu6I6] aggregate. Interestingly, 1 and 3 are a pair of genuine supramolecular isomers controlled by the reaction ratio with an identical chemical composition. In the 2D layered structure of complex 4, the rare “S-shaped-double-bowl” Cu10I10 aggregate is observed and share the Cu2I2 rhomboids to form the 1D infinite [Cu10I10]n column. Complex 5 is a binuclear 18-membered metal–organic macrocycle with [CuI] monomeric units. Complex 6 is also a 2D layer constructed from a 1D infinite [Cu8I8]n aggregate which consists of a 1D infinite [Cu6I6]n column and a [Cu2I2]n ladder. In the overall view, the biimidazole linkers play an important role in the formation of diverse [CumIm] aggregates as well as the resulting structures and topologies. The structural changes of 1/2/3 and 4/5/6 are highly influenced due to the change of the reaction stoichiometry. For 1, 2, 5 and 6, they are non-emissive at both 298 K and 77 K, whereas 3 and 4 exhibit interesting temperature-dependent luminescence properties. The correlation between the luminescence thermochromism and the temperature-dependent variation of the Cu⋯Cu distance is also elucidated.

Solvent-controlled Cd(II) metal–organic frameworks constructed from a tetrapodal silicon-based linker

Two solvent-modulated Cd(II) metal–organic frameworks (MOFs), [Cd4(TCS)2(DMF)2(EtOH)(H2O)7·4DMF]n (1) and [Cd2(TCS)(DMF)2·4H2O]n (2) (H4TCS = tetrakis(3-carboxyphenyl)silicon, DMF = N,N-dimethylformamide), were constructed from a novel tetrapodal silicon-based linker. In 1 and 2, the TCS ligands exhibit different coordination modes and link mononuclear [Cd(COO)4] and tetranuclear [Cd4(COO)8(DMF)4] SBUs (secondary building units) to give 1 and 2 2D 44-sql net and (4,8)-connected 3D framework with rare fluorite (flu) topology, respectively. Dissimilarities in the geometry of both SBUs are originated from the different solvent systems which result in the formation of different networks in each case. The photoluminescence behaviours of them were also discussed.

Effect of hydrophobic chains on the aggregation behavior of cationic silicone surfactants in aqueous solution

Three cationic silicone surfactants, (2-hydroxyethyl)-N,N-dimethyl-3-[tri-(trimethylsiloxy)]silylpropylammonium chloride (Si4ACl), (2-hydroxyethyl)-N,N-dimethyl-3-[bis(trimethylsiloxy)methyl]silylpropylammonium chloride (Si3ACl), and (2-hydroxyethyl)-N,N-dimethyl-3-[bis(trimethylsilylmethyl)methyl]silylpropyl-ammonium chloride (Si3C2ACl), with the same headgroups and different hydrophobic groups were synthesized. Their aggregation behavior in aqueous solution was investigated by surface tension and electrical conductivity. The results show that all the three cationic silicone surfactants perform admirable surface activity. Because of the effect of the hydrophobic groups, the critical micelle concentration values increase following the order Si3C2ACl < Si4ACl < Si3ACl, and Si3C2ACl packs more compactly at the air/water interface compared with Si4ACl and Si3ACl. Electrical conductivity studies show that all the three cationic silicone surfactants have low degree of counterion binding. Thermodynamic parameters (

Comparison of the effect of functional groups on gas-uptake capacities by fixing the volumes of cages A and B and modifying the inner wall of cage C in rht-type MOFs.

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Three- and Eight-Fold Interpenetrated ThSi2 Metal-Organic Frameworks Fine-Tuned by the Length of Ligand

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