Porphyrinic Silver Cluster Assembled Material for Simultaneous Capture and Photocatalysis of Mustard-Gas Simulant.

Silver cluster-assembled materials (SCAMs), by virtue of their tunable structure, accessible surface area and excellent stability, hold great promise as highly efficient catalysts. Herein, we report a new SCAM [Ag12(StBu)6(CF3COO)3(TPyP)]n (denoted as Ag12TPyP) composed of a Ag12 chalcogenolate cluster core stabilized by porphyrinic ligands. Ag12TPyP showed superior sulfur mustard simulant (2-chloroethyl ethyl sulfide, CEES) degradation efficiency and achieved a half lifetime (t1/2) of 1.5 min with 100% selectivity. The experimental results demonstrated that synergistic effects between the silver cluster and photosensitizer ligand promote the efficiency of the generation of singlet oxygen (1O2), which accelerates the decontamination rate. Additionally, benefiting from strong affinity between the silver cluster and CEES, Ag12TPyP exhibits a CEES uptake of 74.2 mg g-1. This work demonstrates that SCAMs offer a new route to the rational design of novel materials for the detoxification of mustard gas.

Reactivity Study of a Pyridyl-1-azaallylgermanium(I) Dimer: Synthesis of Heavier Ether and Ester Analogues of Germanium.

The reactivity study of a pyridyl-1-azaallylgermanium(I) dimer LGe-GeL [1; L = N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)] with different stoichiometric ratios of elemental selenium and tellurium is described. The reactions of 1 with 1 equiv of selenium and tellurium afforded the first examples of heavier ether analogues of germanium, bis(germylene) selenide and telluride LGe(µ-E)GeL [E = Se (2) and Te (3)], respectively. Meanwhile, the reactions of 1 with 2 equiv of selenium and tellurium gave the heavier ester analogues LGe═E(µ-E)GeL [E = Se (4) and (5)]. All compounds have been characterized by X-ray crystallography and multinuclear NMR spectroscopy.

A dual functional probe for "turn-on" fluorescence response of Pb(2+) and colorimetric detection of Cu(2+) based on a rhodamine derivative in aqueous media.

A dual functional probe L based on rhodamine was devised and synthesized. Probe L can sense Pb(2+) and Cu(2+) in aqueous solution through two approaches: a significant fluorescence enhancement caused by Pb(2+) and a visible color change from colorless to orchid induced by Cu(2+). Competitive experiments showed that probe L had high fluorescence sensitivity for Pb(2+) and excellent colorimetric selectivity for Cu(2+) over many environmentally relevant ions. The mechanisms of L for sensing Pb(2+) and Cu(2+) have been well demonstrated by ESI-MS, (1)H NMR titration, IR, the crystal structure of L-Pb(2+) and density functional theory calculation of L-Cu(2+). In addition, fluorescence image detection of Pb(2+) in living cells displayed an enhanced fluorescence effect.

Divalent zinc and cadmium coordination polymers of a new flexible tetracarboxylate ligand: syntheses, crystal structures and properties.

A series of seven metal-organic frameworks, namely, {[Zn(4)(bptc)(2)(bpp)(2)].3.5H(2)O}(n) (1), {[Zn(2)(bptc)(bix)].H(2)O}(n) (2), {[Zn(2)(bptc)(bpe)(1.5)(H(2)O)(3)].H(2)O}(n) (3), [Zn(2)(Hbptc)(mu(3)-OH)(4,4'-bpy)](n) (4), [Cd(2)(bptc)(bpa)(2)(H(2)O)](n) (5), [Cd(2)(bptc)(bpp)(2)(H(2)O)(2)](n) (6), {[Cd(4)(bptc)(2)(bix)(2)(H(2)O)(2)].4.5H(2)O}(n) (7) (bptc = 2,2',3,3'benzophenonetetracarboxylate), have been hydro(solvo)thermally synthesized through the reaction of 2,2',3,3'-benzophenone tetracarboxylic dianhydride (2,2',3,3'-bptda) with divalent zinc and cadmium salts in the presence of ancillary nitrogen ligands (bpa = 1,2-bis(4-pyridyl)ethane, bpe = 1,2-bis(4-pyridyl)ethene, bpp = 1,3-bi(4-pyridyl)propane, bix = 1,4-bis(imidazol-1-ylmethyl)benzene, and bpy = 4,4'bipyridine). Due to various coordination modes and conformations of the versatile 2,2',3,3'-bptc ligand and co-ligands, these complexes exhibit structural and dimensional diversity. In compounds 1-5, M-bptc (M = Zn or Cd) ribbons are connected together through bpp, bix, bpe, bpy and bpa, respectively, to form metal-organic sheets, which are then united together to generate 3D supramolecular structures through interlayer hydrogen bonding, C-H...pi, or pi...pi interactions. In the structure of 4, the ribbon is formed from interlaced coaxial meso-helical Zn-Hbptc chains, and the meso-helical chains are stabilized by the bpa co-ligand in 5. Compound 6 features a 3D metal-organic framework in which [Cd(2)(bptc)](n)meso-helices are bridged by bpp ligands to exhibit a (2,6,2)-connected self-penetrating network with the Schläfli symbol (12)(4(2)12(9)16(4))(4)(2). Compound 7 also exhibits a 3D metal-organic framework in which [Cd(2)(bptc)](n) layers are connected by pillared bix ligands to yield a (4,4,8)-connected network with the Schläfli symbol (4(16)6(12))(4(4)6(2))(4(4)6(2))(2). Compounds 1 and 7 display intense blue fluorescence emissions at 460 and 465 nm, respectively, and may be suitable as excellent candidates of blue fluorescent materials.

Dipyrazinyl sulfoxide complexes of silver(I), zinc(II), and cadmium(II): ligation modes and anion tuning.

The new ligand dipyrazinyl sulfoxide (also named sulfinyldipyrazine and abbreviated as pyz(2)SO) and a series of its metal complexes including {[Ag(pyz(2)SO)](NO(3)).CH(3)CN}(infinity) (1), {[Ag(pyz(2)SO)](PF(6))}(infinity) (2), [Ag(3)(pyz(2)SO)(2)(ClO(4))(3)](infinity) (3), [Ag(pyz(2)SO)(CF(3)CO(2))](infinity) (4), {[Zn(pyz(2)SO)(H(2)O)(4)](NO(3))(2).H(2)O}(infinity) (5), {[Zn(pyz(2)SO)(H(2)O)(2)](ClO(4))(2)}(infinity) (6), and {[Cd(pyz(2)SO)(2)(H(2)O)](ClO(4))(2).H(2)O}(infinity) (7) have been synthesized and characterized by single-crystal X-ray analysis. The counteranions in these complexes prefer to be embraced by a pair of pi-acidic heterocyclic rings via anion-pi interactions, which consequently affect the process of supramolecular assembly. Seven distinct ligation modes of pyz(2)SO involving various bonding combinations of the sulfoxide oxygen and/or pyrazinyl nitrogen atoms (labeled A-G) are observed. Diverse coordination motifs such as (4,4) network, ladder-type, necklace-like, linear, and zigzag-chain structures are found in 1-7. Interestingly, the sulfoxide group of the pyz(2)SO ligand exhibits unusual dipolar sulfinyl...sulfinyl and S=O...pi(pyrazinyl) intermolecular interactions in the supramolecular assemblies of neat pyz(2)SO, 1, and 3-5.

Synthesis, structure and dioxygen reactivity of a bis(micro-iodo)dicopper(I) complex supported by the [N-(3,5-di-tert-butyl-2-hydroxybenzyl)-N,N-di-(2-pyridylmethyl)]amine ligand.

The air-sensitive bis(micro-iodo)dicopper(I) complex 1 supported by [N-(3,5-di-tert-butyl-2-hydroxybenzyl)-N,N-di-(2-pyridylmethyl)]amine (L) has been prepared by treating copper(I) iodide with L in anhydrous THF. Compound 1 crystallizes as a dimer in space group C2/c. Each copper(I) center has distorted tetrahedral N2I2 coordination geometry with Cu-N(pyridyl) distances 2.061(3) and 2.063(3) A, Cu-I distances 2.6162(5) and 2.7817(5) and a Cu...Cu distance of 2.9086(8) A. Complex 1 is rapidly oxidized by dioxygen in CH2Cl2 with a 1 : 1 stoichiometry giving the bis(micro-iodo)peroxodicopper(II) complex [Cu(L)(micro-I)]2O2 (2). The reaction of 1 with dioxygen has been characterized by UV-vis, mass spectrometry, EPR and Cu K-edge X-ray absorption spectroscopy at low temperature (193 K) and above. The mass spectrometry and low temperature EPR measurements suggested an equilibrium between the bis(micro-iodo)peroxodicopper(II) complex 2 and its dimer, namely, the tetranuclear (peroxodicopper(II))2 complex [Cu(L)(micro-I)]4O4 (2'). Complex 2 undergoes an effective oxo-transfer reaction converting PPh3 into O=PPh3 under anaerobic conditions. At sufficiently high concentration of PPh3, the oxygen atom transfer from 2 to PPh3 was followed by the formation of [Cu(PPh3)3I]. The dioxygen reactivity of 1 was compared with that known for other halo(amine)copper(I) dimers.

Chemistry and biological activities of caffeic acid derivatives from Salvia miltiorrhiza.

Caffeic acid (3,4-dihydroxycinnamic acid), one of the most common phenolic acids, frequently occurs in fruits, grains and dietary supplements for human consumption as simple esters with quinic acid or saccharides, and are also found in traditional Chinese herbs. Caffeic acid derivatives occur as major water-soluble components of Salvia miltiorrhiza, including caffeic acid monomers and a wide variety of oligomers. This review provides up-to-date coverage of this class of phenolic acids in regard to structural classification, natural resources, chemical and biosyntheses, analytical methods and biological activities including antioxidant, anti-ischemia reperfusion, anti-thrombosis, anti-hypertension, anti-fibrosis, antivirus and antitumor properties. Special attention is paid to both structural classification and biological activities. The structural diversity and the pronounced biological activities encountered in the caffeic acid derivatives of S. miltiorrhiza indicate that this class of compounds is worthy of further studies that may lead to new drug discovery.

Synthesis, Crystal Structure, and Second-Order Optical Nonlinearity of Bis(2-chlorobenzaldehyde thiosemicarbazone)cadmium Halides (CdL(2)X(2); X = Br, I).

The new Schiff base ligand 2-chlorobenzaldehyde thiosemicarbazone (L, 1) has been synthesized and characterized by spectral techniques and single-crystal X-ray analysis. Crystals of 1 are monoclinic, space group P2(1)/n with a = 12.964(4) Å, b = 5.131(5) Å, c = 4.970(1) Å, beta = 94.32(2) degrees, and Z = 4. The thiosemicarbazone moiety adopts a configuration with N(1) cis to N(3) and places the E configuration about both the bonds C(1)-N(2) and C(2)-N(3). The monodentate behavior of the neutral ligand (L) has been investigated in two cadmium halides CdL(2) Br(2) (2) and CdL(2)I(2) (3). Compound 2 crystallizes in space group Cc witha = 8.175(1) Å, b = 14.176(1) Å, c = 21.073(1) Å, beta = 94.02(1) degrees, and Z = 4. Compound 3 crystallizes in space group P&onemacr; with a = 10.9577(1) Å, b = 16.174(1) Å, c = 7.878(1) Å, alpha = 100.50(1) degrees, beta = 109.39(1) degrees, gamma = 83.67(1) degrees, and Z = 2. The coordination geometry about the cadmium(II) atom in compound 2 conforms to a tetrahedral configuration with two sulfur atoms from two unequivalent neutral ligands and two bromide atoms. Whereas the coordination geometry about the cadmium(II) atom in compound 3 is (4 + 1) distorted trigonal bipyramidal with two iodide atoms and one sulfur atom in the equatorial plane, the other thiosemicarbazone sulfur and the iodide atom I(1a) of an adjacent moiety occupy the axial positions. Compound 2 exhibits powder SHG efficiencies ca. 20 times that of urea, whereas compound 3 does not exhibit any SHG efficiency. Theory and experiment suggested that intermolecular contact is the main factor controlling the SHG efficiencies of compounds.