In response to the need for rapid screening of combinatorial libraries to identify new lead compounds during drug discovery, we have developed an on-line combination of ultrafiltration and electrospray mass spectrometry, called pulsed ultrafiltration mass spectrometry, which facilitates the identification of solution-phase ligands in library mixtures that bind to solution-phase receptors. After ligands contained in a library mixture were bound to a macromolecular receptor, e.g., human serum albumin or calf intestine adenosine deaminase, the ligand-receptor complexes were purified by ultrafiltration and then dissociated using methanol to elute the ligands into the electrospray mass spectrometer for detection. Ligands with dissociation constants in the micromolar to nanomolar range were successfully bound, released, and detected using this method, including warfarin, salicylate, furosemide, and thyroxine binding to human serum albumin, and erythro-9-(2-hydroxy-3-nonyl)adenine binding to calf intestine adenosine deaminase. Repetitive bind- and-release experiments demonstrated that the receptor could be reused. Thus, pulsed ultrafiltration mass spectrometry was shown to provide a simple and powerful new method for the screening of combinatorial libraries in support of new drug discovery.

No abstract

Acid intercalation-exfoliated 2D Bi shows strong nonlinear NIR responses associated with multi-timescale carrier dynamics and is used for mode-locking lasers.

Upon single-crystal-to-single-crystal (SCSC) oxidation/reduction, reversible structural transformations take place between the anionic porous zeolite-like Cu(I) framework and a topologically equivalent neutral Cu(I)Cu(II) mixed-valent framework. The unique conversion behavior of the Cu(I) framework endowed it as a redox-switchable catalyst for the direct arylation of heterocycle C-H bonds.

To systematically explore the effect of polynuclear complexes on photocatalytic degradation of the organic dyes, a series of coordination complexes containing CdII clusters, formulated as {[Cd3L2(H2O)5]·H2O} n (1), {[Cd3L2(hbmb)(H2O)2]·2.5H2O} n (2), {[Cd3L2(btbb)(H2O)2]·2EtOH·1.5H2O} n (3), and {[Cd6L4(bipy)2(H2O)6]·3H2O} n (4) (H3L = 3,4-bi(4-carboxyphenyl)-benzoic acid, hbmb = 1,1′-(1,6-hexane)bis(2-methylbenzimidazole), btbb = 1,4-bis(2-(4-thiazolyl)benzimidazole-1-ylmethyl)benzene, 4,4′-bipy = 4,4′-bipyridine), have been designed and synthesized. Complex 1 based on trinuclear CdII clusters exhibits a new (3,3,6)-connected 3D framework. 2 belongs to a (3,3,8,8)-connected tfz-d topology net with pillar-layered frameworks assembled by two kinds of trinuclear CdII clusters. 3 is a 3D pillar-layered framework, which features a (3,8)-connected tfz-d net based upon one kind of trinuclear CdII cluster. 4 presents a new 3D (3,6,10)-connected framework with dinuclear and tetranuclear clusters. The photocatalytic properties of complexes 1–4 have been studied in detail. Remarkably, 1–4 all reveal good photocatalytic activity in MB/MO degradation. The optical energy gap calculated by the diffuse reflectivity spectra of 1–4 are consistent with their degradation rates. Moreover, the experimental results further demonstrate that the cluster complexes containing different kinds of nuclei may exert different impact on the decomposition of disparate organic dyes.

SC–SC solvent-assisted linker exchange (SALE) in MOF materials is of high interest due to the potential applications. In this work, we reported an efficient transformation via SALE in a water-stable 3D MOF ({[Ni1.5(L)­(4,4′-azobpy)­(H2O)]·6.5H2O} n (1)) (H3L = 1-aminobenzene-3,4,5-tricarboxylic acid). The reaction progress of SALE was monitored and proved by single crystal XRD, PXRD and UV–vis absorption analyses, and the structural integrity of progeny MOFs {[Ni1.5(L)­(4,4′-bpy)­(H2O)]·6H2O} n (2), {[Ni1.5(L)­(bpe)­(H2O)]·8.5H2O} n (3), and {[Ni1.5(L)­(NH2-bpy)­(H2O)]·7.5H2O} n (4) were maintained very well, which is rarely in reported MOF materials. Theoretical calculations and the analyses of core–shell crystals give us better understanding of the exchange process. Interestingly, MOFs 2 and 3 obtained by SALE methods showed the different magnetic behavior comparing to parent MOF 1. Especially, because of the functional −NH2 group, progeny MOF 4 displayed the good capability to remove Hg2+ ions with an adsorption capacity of 93.693 mg/g. This work provides a new way to develop multifunctional MOF materials.

Two novel Eu metal-organic frameworks (MOFs), namely {[Eu(pdba)(HO)]·2HO} (1) and {[Eu(pdba)(HO)]·5HO} (2), were prepared with 4'-(1H-pyrazol-3-yl)-[1,1'-biphenyl]-3,5-dicarboxylic acid (Hpdba) under hydrothermal conditions. MOF 1 exhibits a 3D supramolecular structure assembled from the ππ interactions between the benzene rings of the ligands, whereas 2 comprises a 3D structure through coordination connection between nitrogen atom and Eu. It is worth noting that the two MOFs showed good luminescence performance and high-sensitivity fluorescence quenching behavior toward Fe (Cr) and nitrobenzene. Furthermore, the experimental results for stability in water and cycle test show that these two MOFs can be used as potential fluorescent probes.

No abstract