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We report bifunctional three-dimensional (3D) Cu-MOFs with high selectivity of CO(2) over N(2) and H(2) as well as high catalytic activity for transesterification of esters. The Cu-MOFs containing Cu(2) dinuclear units connected by glutarates and bipyridyl ligands are formulated as [{Cu(2)(Glu)(2)(μ-bpa)}·(CH(3)CN)](n) (1) and [{Cu(2)(Glu)(2)(μ-bpp)}·(C(3)H(6)O)](n) (2) (Glu = glutarate, bpa = 1,2-bis(4-pyridyl)ethane, bpp = 1,3-bis(4-pyridyl)propane). These two new bifunctional 3D Cu-MOFs possess very similar pore shape with different pore dimensions. Their gas sorption behaviors were investigated by using CO(2), N(2) and H(2) at suitable temperatures. Both MOFs exhibited good CO(2) selectivity over N(2) and H(2). MOF 1 having a smaller pore dimension exhibited much higher CO(2) adsorption enthalpy than MOF 2 having a larger pore dimension. However, MOF 2 exhibited more enhanced CO(2) uptake ability than MOF 1. A subtle variation of pore dimension indeed influenced the CO(2) uptake ability somewhat significantly especially at higher temperatures such as 273 K and 298 K. Heterogeneous catalytic activities of the MOFs were also investigated in detail. Only MOF 1 appeared to be an efficient, mild, and easily recyclable heterogeneous catalyst for the transesterification of esters and constitutes a promising class of heterogeneous catalysts that allowed reuse without a significant loss of activity through twenty runs with ester.

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Zinc sensors based on 2,3-dipicolylamine (DPA) and quinoline have been synthesized. They fluoresced in the presence of Zn(2+) and remained fluorescent when other metal ions were present. Fluorescence enhancement of the sensors was not seen for most other metal ions. In vitro studies with fibroblasts showed fluorescence when sensor and Zn(2+) were present. As seen by single crystal X-ray analysis, four nitrogens from the sensor bind to Zn(2+). These new sensors have lower binding constants than the pentadentate sensors based on 2,2-DPA.

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A highly selective and sensitive fluorescent chemosensor exhibited enhanced fluorescence in the presence of Al3+ and in living cells.

The participation of multiple active oxidants generated from the reactions of two manganese(III) porphyrin complexes containing electron-withdrawing and -donating substituents with peroxyphenylacetic acid (PPAA) as a mechanistic probe was studied by carrying out catalytic oxidations of cyclohexene, 1-octene, and ethylbenzene in various solvent systems, namely, toluene, CH(2) Cl(2) , CH(3) CN, and H(2) O/CH(3) CN (1:4). With an increase in the concentration of the easy-to-oxidize substrate cyclohexene in the presence of [(TMP)MnCl] (1a) with electron-donating substituents, the ratio of heterolysis to homolysis increased gradually in all solvent systems, suggesting that [(TMP)Mn-OOC(O)R] species 2a is the major active species. When the substrate was changed from the easy-to-oxidize one (cyclohexene) to difficult-to-oxidize ones (1-octene and ethylbenzene), the ratio of heterolysis to homolysis increased a little or did not change. [(F(20) TPP)Mn-OOC(O)R] species 2b generated from the reaction of [(F(20) TPP)MnCl] (1b) with electron-withdrawing substituents and PPAA also gradually becomes involved in olefin epoxidation (although to a much lesser degree than with [(TMP)Mn-OOR] 2a) depending on the concentration of the easy-to-oxidize substrate cyclohexene in all aprotic solvent systems except for CH(3) CN, whereas Mn(V)=O species is the major active oxidant in the protic solvent system. With difficult-to-oxidize substrates, the ratio of heterolysis to homolysis did not vary except for 1-octene in toluene, indicating that a Mn(V)=O intermediate generated from the heterolytic cleavage of 2b becomes a major reactive species. We also studied the competitive epoxidations of cis-2-octene and trans-2-octene with two manganese(III) porphyrin complexes by meta-chloroperbenzoic acid (MCPBA) in various solvents under catalytic reaction conditions. The ratios of cis- to trans-2-octene oxide formed in the reactions of MCPBA varied depending on the substrate concentration, further supporting the contention that the reactions of manganese porphyrin complexes with peracids generate multiple reactive oxidizing intermediates.