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Trichocadinins B-G (1-6), six new cadinane-type sesquiterpene derivatives, each with C-14 carboxyl functionality, were isolated from the culture extract of Trichoderma virens QA-8, an endophytic fungus obtained from the fresh inner tissue of the medicinal plant Artemisia argyi. Their structures were elucidated by interpretation of the NMR spectroscopic and mass spectrometric data. The structures and absolute configurations of compounds 1 and 3 were confirmed by X-ray crystallographic analysis. Compounds 1-3 showed antibacterial and antifungal activity.

Carotane sesquiterpenes are commonly found in plants but are infrequently reported in the fungal kingdom. Chemical investigation of Trichoderma virens QA-8, an endophytic fungus associated with the inner root tissue of the grown medicinal herb Artemisia argyi H. Lév. and Vaniot, resulted in the isolation and characterization of five new carotane sesquiterpenes trichocarotins I–M (1–5), which have diverse substitution patterns, and seven known related analogues (6–12). The structures of these compounds were established on the basis of a detailed interpretation of their NMR and mass spectroscopic data, and the structures including the relative and absolute configurations of compounds 1–3, 5, 9, and 10 were confirmed by X-ray crystallographic analysis. In the antibacterial assays, all isolates exhibited potent activity against Escherichia coli EMBLC-1, with MIC values ranging from 0.5 to 32 µg/mL, while 7β-hydroxy CAF-603 (7) strongly inhibited Micrococcus luteus QDIO-3 (MIC = 0.5 µg/mL). Structure-activity relationships of these compounds were discussed. The results from this study demonstrate that the endophytic fungus T. virens QA-8 from the planted medicinal herb A. argyi is a rich source of antibacterial carotane sesquiterpenes, and some of them might be interesting for further study to be developed as novel antibacterial agents.

The AcOEt extract of Artemisia argyi-derived fungus Trichoderma koningiopsis QA-3 showed potent inhibitory activity against pathogenic bacteria. Fractionation of the extract resulted in the isolation of three new polyketides (1-3) and two new terpenoids (4 and 5), together with three known metabolites (6-8). Their chemical structures were analyzed by NMR spectra, ECD, HR-ESI-MS or HR-EI-MS, optical rotation, and X-ray crystallographic data, as well as by comparison with literature reports. In the antibacterial assays, 3-hydroxyharziandione (4) showed potent activity against human pathogen Escherichia coli with an MIC value of 0.5 μg/mL, while 6-(3-hydroxypent-1-en-1-yl)-2H-pyran-2-one exhibited strong activity against marine-derived aquatic pathogen Micrococcus luteus with an MIC value of 1.0 μg/mL.

Six novel diacetoxyboron complexes of bis-β-diketones linked thienothiophene moiety were synthesized from acetoacetone by cyclization, Claisen condensation and chelation reaction. The obtained complexes were confirmed by means of 1H NMR, FTIR, MS and elemental analysis and their electrochemical and photoluminescent properties were investigated by cyclic voltammetry, UV–vis absorption and fluorescence spectroscopy. The results showed that these diacetoxyboron complexes yielded a blue emission in DMF solution and emitted a greenish-yellow emission in powders and PMMA films. Especially, diacetoxyboron bis-β-diketonate with tert-butylphenyl thienothiophene exhibited the most intense photoluminescent intensity, highest quantum efficiency (Φu = 0.95) in solution and longest lifetime value (τ = 38.42 μs) in PMMA film among these complexes. In addition, these diacetoxyboron complexes showed the low-lying LUMO energy levels (2.71–2.75 eV), which was suitable for electron transfer.

Trichocadinins B-G (

Eight new highly oxygenated fungal polyketides, namely, 15-hydroxy-1,4,5,6-tetra-epi-koninginin G (1), 14-hydroxykoninginin E (2), koninginin U (3), 4′-hydroxykoninginin U (4), koninginin V (5), 14-ketokoninginin B (6), 14-hydroxykoninginin B (7), and 7-O-methylkoninginin B (8), together with six known related analogues (9–14), were isolated from Trichoderma koningiopsis QA-3, a fungus obtained from the inner root tissue of the well known medicinal plant Artemisia argyi. All these compounds are bicyclic polyketides, with compound 1 contains unusual hemiketal moiety at C-5 and compounds 2–14 having ketone group at C-1 and double bond at C-5(6). The structures and absolute configurations of the new compounds were established by spectroscopic analysis, X-ray crystal diffraction, modified Mosher’s method, and ECD calculation. The absolute configurations of the known compounds 9, 10, and 12 were determined by X-ray crystal diffractions for the first time. The antimicrobial activities against human pathogen, marine-derived aquatic bacteria, and plant-pathogenic fungi of compounds 1–14 were evaluated, and compound 1 showed remarkable activity against aquatic pathogen Vibrio alginolyticus with MIC value 1 µg/mL, which is as active as that of the positive control.

Artemisia argyi is broadly cultivated as a medicinal plant in Qichun of Hubei province in central China. Five new fungal polyketides (1–5) and two known analogues (6 and 7) were isolated and identified from the culture extract of Trichoderma koningiopsis QA-3, an endophytic fungus obtained from the inner tissue of Artemisia argyi that was collected from Qichun. Their structures were elucidated by detailed interpretation of the spectroscopic data and the structures and absolute configurations of compounds 1–4 were confirmed by X-ray crystallographic analysis. Compounds 1–3 are tricyclic polyketides possessing octahydrochromene framework and having ketal unit in their structures, while compounds 4/7 and 5/6 are related bicyclic and tricyclic analogues, respectively. The antibacterial activities against human pathogen E. coli and seven marine-derived aquatic pathogens as well as against eight agro-pathogenic fungi for each of the isolated compounds were evaluated. Compounds 1–7 showed activity against human pathogen Escherichia coli (each with MIC 64 μg mL−1), while 1 and 7 inhibited most of the tested aquatic bacteria and agro-pathogenic fungi (MICs ranging from 4 to 64 μg mL−1), respectively.

A highly selective and sensitive oxadiazole-based chemosensor, 2-(2-hydroxyphenyl)-5-(4-dimethylaminophenyl)-1,3,4-oxadiazole, was designed and synthesized. The UV–vis absorption and fluorescence behavior between chemosensor and Cu 2+ ion were investigated in 9:1 (v/v) ethanol–Hepes buffer (pH = 7.0) solution. The fluorescence of the chemosensor can be dramatically quenched by Cu 2+ ion in aqueous solution, whereas it was not any interference from other metal ions such as Al 3+ , Ba 2+ , Ca 2+ , Cd 2+ , Co 2+ , Cr 3+ , Fe 3+ , Hg 2+ , K + , Mg 2+ , Na + , Ni 2+ , Pb 2+ and Zn 2+ . The complex formed between chemosensor and Cu 2+ ion is found to be 2:1 stoichiometry with an association constant of 6.38 × 10 4 M −1 . The detection limit for Cu 2+ ion determination is 8.71 × 10 −7 mol L −1 . In addition, the binding mode between chemosensor and Cu 2+ ion was confirmed by 1 H NMR and mass spectrometry.

Two fluorinated β-diketones and their six europium (III) complexes using 2,2-dipyridine, 1,10-phenanthroline or 4′-phenyl-terpyridine as the secondary ligand were synthesized and characterized. The photoluminescence behavior for these complexes was investigated in solid state in detail. Based on the emission spectra and luminescence decay curves of these complexes in solid state, the Judd−Ofelt intensity parameters (Ωt), lifetime (τ) and luminescence quantum efficiency (η) were determined. The Ω2 values indicate that the europium (III) ion is in a highly polarizable chemical environment in these complexes. Europium (III) complexes with the secondary ligands 2,2-dipyridine or 1,10-phenanthroline exhibited much better photoluminescence properties than complexes with the secondary ligand 4′-phenyl-terpyridine. Especially, europium (III) complexes of 4,4,4-trifluoro-1-(4-fluorophenyl)-butane-1,3-dione containing the secondary ligands 2,2-dipyridine or 1,10-phenanthroline showed a longer lifetime (τ = 0.799 and 0.826 ms, respectively) and a higher luminescence quantum efficiency (η = 56.5 and 56.1, respectively) among these complexes.

A novel bispyrazole, 2,6-bis(5-phenyl-1H-pyrazol-3-yl)-pyridine, was designed and synthesized. The bispyrazole showed extreme selectivity for Ni2+ over other metal ions such as Ag+, Al3+, Ba2+, Ca2+, Cd2+, Co2+, Cr3+, Cu2+, Fe3+, Hg2+, K+, Mg2+, Na+, Pb2+, and Zn2+ in MeOH–H2O solution. The sensing sensitivity and binding properties of the bispyrazole for nickel(II) ion were investigated by fluorescent spectroscopic techniques. It was found that the bispyrazole possessed high selectivity and sensitivity toward Ni2+ over other metal ions. The binding stoichiometry was confirmed as 1:1 (bispyrazole/Ni2+) by Job plot experiment and the linearity of the Benesi–Hildebrand plot. The binding constants K and thermodynamic parameters (ΔH, ΔG, and ΔS) at different temperatures were obtained. Meanwhile, the detection limit of the bispyrazole for Ni2+ was determined to be 3.25 × 10−7 mol L−1.

Six novel difluoroboron complexes with fluoroquinolones were prepared from fluoroquinolones via complexation with boron trifluoride etherate in DMF–CH2Cl2 solution. Their spectroscopic properties were investigated by UV–vis absorption, FTIR, 1H NMR and fluorescence spectroscopic techniques. The results showed that these difluoroboron complexes exhibited the intense fluorescence emission at 401–579 nm under UV visible illumination and possessed a relatively high quantum yield in DMSO solution and solid state. Especially, the difluoroboron complex of Levofloxacin displayed the strongest fluorescence and highest quantum yield (Φu = 0.63) in these difluoroboron complexes, due to its conjugated rigid plane system via four fused six-membered cyclic structures.

A series of six new thienothiophene functionalized difluoroboron bis-β-diketonates were synthesized and characterized. Their photophysical properties were investigated by UV–vis absorption, fluorescence spectroscopy and the method of CIE chromaticity in solution and powders. The results showed that these difluoroboron complexes yielded a blue-green emission at 474–500 nm in DMF solution and emitted a green to yellow emission at 541–587 nm in powders. Especially, the complex 3c showed the stronger fluorescence intensity, much higher quantum yield (Φu = 0.89) in DMF solution and larger Stokes shifts (∆λstokes = 149 nm), longer lifetime value (τ = 3.54 ns) in powders as compared to other complexes. The CIE coordinate of the complex 3c was positioned in an ideal orange-yellow region of the chromaticity diagram. Meanwhile, their electrochemical properties were also studied by the cyclic voltammetry; the HOMO, LUMO energy levels and energy band gaps were determined from the onset oxidation and reduction potentials.

The fluorinated β-diketone ligand, 4,4,4-trifluoro-1-(6-methoxy- naphthalen-2-yl)-butane-1,3-dione (HL), and its ternary europium (III) complexes using water (H2O), 2,2-dipyridine (Bipy), 1,10-phenanthroline (Phen) and 4′-phenyl-terpyridine (Phterpy) as the secondary ligand were synthesized and characterized by elemental analysis, FT-IR, 1H NMR, UV–vis absorption, ESI–MS and fluorescence spectroscopic techniques. All these europium complexes exhibited the characteristic emission bands that arise from the 5D0 → 7FJ (J = 0–4) transitions of the europium ion in solid state. Based on their emission spectra and lifetimes, the Judd–Ofelt intensity parameters (Ω2 and Ω4), the radiative decay rate Arad, the nonradiative rates Anrad, and the quantum efficiency (η) were determined and compared. The ternary complexes, EuL3·Bipy, EuL3·Phen and EuL3·Phterpy, exhibited much higher quantum efficiencies and lifetime values, which can be attributed to the displacement of water molecules from the coordination sphere by the heterocyclic nitrogen donors. Especially, the complex EuL3·Phen exhibited the longest lifetime τ (0.704 ms) and the highest luminescence quantum efficiency η (47.9%) among these complexes. Meanwhile, complexes EuL3·Bipy, EuL3·Phen and EuL3·Phterpy also displayed higher Ω2 values than the complex EuL3·2H2O, indicating their hypersensitive character of the 5D0 → 7F2 transition and a highly polarizable chemical environment around the europium(III) ion.

Some novel difluoroboron bis-β-diketonates containing a pyridyl moiety were synthesized from diethyl 2,6-pyridinedicarboxylate via Claisen condensation with the corresponding aryl methyl ketones and followed by complexation with boron trifluoride etherate. Their spectroscopic behaviors were studied by FTIR, 1H NMR, UV–Vis, and fluorescence spectroscopic techniques. The results indicated that difluoroboron bis-β-diketonates exhibited violet or blue fluorescence emission at 428–454 nm under UV illumination in DMSO and possessed high extinction coefficients. It was found that the nature of the substituents at benzene ring in bis-β-diketone ligands had a significant impact on the photoluminescence behaviors of difluoroboron complexes. The complex 5b exhibited the strongest photoluminescence intensity and highest quantum yield (Φ u = 0.93), due to two strong electron-donating methoxyl moieties in molecule and the compound 4b displayed the lowest photoluminescence intensity and quantum yield, assigned to the heavy atom effect of the chlorine atom in its molecule. The photoluminescence intensity and quantum yield of these difluoroboron complexes decreased in the sequence, 5b > 2b > 1b > 3b > 4b.

Three 2,6-bis (1,3,4-oxadiazol-2-yl) pyridine derivatives were synthesized and their structures were conformed by1H NMR, FTIR, MS techniques and elemental analysis. The UV–Vis absorption and fluorescence emission spectra of these compounds were investigated in chloroform solution. The results showed that these bis-1,3,4-oxadiazole derivatives had broad and strong absorption at 278−302 nm in the UV–Vis spectra and exhibited fluorescence emission at 338 −367 nm under UV illumination in fluorescence spectra. It was found that the nature of the substituents at benzene ring in bis-1,3,4-oxadiazole derivatives had a significant impact on their photoluminescence behaviors.

A new tris-β-diketone ligand, 2-[4,6-bis-(1-benzoyl-2-oxo-2-phenyl-ethyl)-[1,3,5]triazin-2-yl]-1,3-diphenyl-propane-1,3-dione ( H 3 L ), and its trinuclear europium complexes, Eu 3 (DBM) 6 L ( C1 ), Eu 3 (DBM) 6 (Bipy) 3 L ( C2 ) and Eu 3 (DBM) 6 (Phen) 3 L ( C3 ) were synthesized and their spectroscopic behaviors were studied by FT-IR, 1 H NMR, UV–vis and photoluminescence spectroscopic techniques. These europium complexes exhibited the characteristic emission bands that arise from the 5 D 0 → 7 F J ( J = 0–4) transitions of the europium ion in solid state. The Ω 2 and Ω 4 intensity parameters, lifetime ( τ ) and luminescence quantum yield ( η ) were calculated according to the emission spectra and luminescence decay curves in solid state. The results indicated that these trinuclear europium complexes displayed a longer lifetime ( τ ) and higher luminescence quantum efficiency ( η ), especially complexes C2 ( τ = 0.820 ms, η = 46.5%) and C3 ( τ = 0.804 ms, η = 47.4%), which due to the effect of two additional europium ion lumophors and the introduction of the third ligands, Bipy or Phen in trinuclear complexes. Their Ω 2 values demonstrated that the europium ion in these complexes is in a highly polarizable chemical environment.

Six new bis-β-diketones (RCOCH2CO-C7H7N-COCH2COR) were synthesized from 3,5-diacetyl-2,6-dimethylpyridine via Claisen condensation with the corresponding esters, and then reacted with boron trifluoride etherate to afford difluoroboron bis-β-diketonate derivatives. Their spectroscopic properties were investigated by UV–vis, FTIR, 1H NMR and fluorescence spectroscopic techniques. It was found that these boron complexes exhibited violet or blue fluorescence emission at 422–445 nm and possessed high extinction coefficients. The results indicate that the extending π-conjugation can increase the fluorescence intensity and quantum yield for these boron complexes. Especially, the compound 2b displayed the stronger fluorescence intensity and the highest fluorescence quantum yield (Φu = 0.94) in these boron compounds. However, compounds 2c and 2d had the lower fluorescence intensity and quantum yield as a result of the heavy atom effect of the chlorine atom in the molecules.

The synthesis of a novel bispyrazole derivative 2,6-bis (5-(p-methylphenyl)-1-H-pyrazol-3-yl) pridine (BMPP) was described and its structure was conforrmed by1H NMR, FTIR, MS techniques and elemental analysis. The interactions of Zn2+ion with BMPP were assessed by fluorescence quenching techniques. The results revealed that the quenching effect is resulting from the formation of Zn2+-BMPP nonfluorescent complex. The SternVolmer curves suggested that the quenching effect was the static quenching. The main action forces of these reactions was spontaneous, mainly hydrogen bonds and ΔS-driven obtained by using thermodynamic equations.

Three novel europium complexes with 1-(4-tert-butylphenyl)-3-(2-naphthyl)-propane-1,3-dione (TNPD) and 2,2-dipyridine (Bipy) or 1,10-phenan-throline (Phen) were synthesized and confirmed by FT-IR, 1H NMR, UV–vis absorption and elemental analysis. Photoluminescence behavior of complexes Eu(TNPD)3, Eu(TNPD)3⋅Bipy and Eu(TNPD)3⋅Phen were investigated in detail. Their emission spectra exhibited the characteristic emission bands that arise from the 5D0 → 7FJ (J = 0–4) transitions of the europium ion in solid state. Meanwhile, the results of their lifetime decay curves indicated that only one chemical environment existed around the europium ion. The intrinsic luminescence quantum efficiency (η) and the experimental intensity parameters (Ωt) of europium complexes were determined according to the emission spectra and luminescence decay curves in solid state. The complex Eu(TNPD)3⋅Phen showed much longer lifetime (τ) and higher luminescence quantum efficiency (η) than complexes Eu(TNPD)3 and Eu(TNPD)3⋅Bipy.

Five new difluoroboron complexes with 4-pyridyl-β-diketones were synthesized and their structures were confirmed by elemental analysis, IR, 1H NMR, ESI-MS and UV–vis spectroscopy. Their photoluminescence behavior was studied in DMF solution and solid state. The quantum yields (Φu) of complexes 2a–2e in DMF solution were measured relative to quinine sulfate and their lifetime values (τ) were calculated according to the luminescence decay curves in the solid state. From these data, the difluoroboron complexes exhibited the excellent photoluminescence properties. Especially, the complexes 2d and 2e displayed the stronger photoluminescence intensity, much higher quantum yield and longer lifetime value as compared to complexes 2a, 2b and 2c. The results indicate that the substituents at the 4-position on benzene ring have a significant impacts on the photoluminescence properties of the difluoroboron complexes.

Preparation and photoluminescence behavior of four new europium (III) ternary complexes with β-diketones (1-(6-methoxy-naphthalen-2-yl)-3-phenyl-propane-1,3-dione (MNPPD) and 1-(4-tert-butyl-phenyl)-3-(6-methoxy-naphthalen-2-yl)-propane-1,3-dione (BPMPD)) and 2,2-dipyridine (Bipy) or 1,10-phenanthroline (Phen) were reported, in the solid state. Complexes Eu(MPPD) 3 ·Bipy, Eu(BMPD) 3 ·Bipy, Eu(MPPD) 3 ·Phen and Eu(BMPD) 3 ·Phen were characterized by elemental analysis, FT-IR, 1 H NMR, UV–vis absorption. The emission spectra show narrow emission bands that arise from the 5 D 0 → 7 F J ( J = 0–4) transitions of the europium ion. Based on the emission spectra and luminescence decay curves in solid state, the intensity parameters ( Ω t ), lifetime ( τ ) and emission quantum efficiency ( η ) were determined. The Ω 2 values indicate that the Eu(III) ion in these complexes is in a highly polarizable chemical environment. Complexes Eu(MPPD) 3 ·Bipy and Eu(MPPD) 3 ·Phen showed a longer lifetime ( τ ) and a higher luminescence quantum efficiency ( η ), which indicated that the energy transfer to the europium ion from MNPPD ligand is more efficient than that from BPMPD ligand.

Five pyridyl-β-diketones were synthesized by Claisen condensation of ethyl nicotinate with various aryl methyl ketones in benzene in the presence of sodium amide as the base, and then reacted with boron trifluoride diethyl etherate in dichloromethane to afford some new boron difluoride pyridyl-β-diketonate derivatives. The compounds obtained were characterized using FTIR, (1)H NMR, elemental analysis and mass spectrometry. Their optical properties were studied in DMF by UV-vis absorption and fluorescence spectroscopy. The results showed that these boron complexes exhibited intense fluorescence in the blue-green region (420-490 nm) under UV radiation with a relatively high quantum yield. Especially, compounds 4b and 5b displayed much higher quantum yield as compared to compounds 1b, 2b and 3b.

A novel fluorescent chemosensor based on the oxadiazole, 2-(2-hydroxyphenyl)-5-(4-methoxyphenyl)-1,3,4-oxadiazole, was designed and synthesized. The interaction of the oxadiazole with different metal ions had been investigated through UV–vis absorption and fluorescence spectra in 9:1 (v/v) ethanol-water (pH = 7.0) solution. The oxadiazole showed a pronounced fluorescence enhancement at 430 nm upon addition of Zn2 + in aqueous solution, whereas it had no apparent interference from other metal ions. The results indicated that the oxadiazole possessed high selectivity and sensitivity to Zn2 + ion. The stoichiometric ratio between the oxadiazole and Zn2 + ion was calculated to be 2:1 by Job plot experiment, meanwhile their binding modes was confirmed by 1H NMR and mass spectrometry. Their association constant was determined to be 1.95 × 105 M− 1 and the detection limit for Zn2 + ion was 6.14 × 10− 7 mol/L.

The β-diketone ligand, 1-(4-methoxyphenyl)-3-phenylpropane-1,3-dione (MPPD), and its binary Eu(III) complexes Eu(MPPD) 3 , ternary complexes Eu(MPPD) 3 ·Bipy with 2,2-dipyridine (Bipy) and Eu(MPPD) 3 ·Phen with 1,10-phenanthroline (Phen) were prepared. The complexes were characterized with by elemental analysis, FT-IR, 1 H NMR, UV–vis absorption, thermogravimetric analysis (TGA), ESI-MS and fluorescence spectroscopic techniques. TGA results showed that these complexes have good thermal stability. The emission spectra for complexes 2 – 4 exhibited the characteristic emission bands that arise from the 5 D 0 → 7 F J ( J = 0–4) transitions of the europium ion in solid state and chloroform solution. Based on the emission spectra in solid state, the Eu(III) ion could be sensitized efficiently by the ligands to some extent, in particular, in the ternary system, the secondary ligands Bipy and Phen acting as a light-harvesting center was involved in the highly efficient energy transfer process. In addition, the experimental intensity parameters, Ω 2 and Ω 4 were calculated from the fluorescence emission spectra. The radiative decay rate A rad , the nonradiative rates A nrad , the lifetime ( τ ) and the luminescent quantum yield ( η ) were determined and analyzed.

The reactions of 3(5)-(4-methoxyphenyl)-5(3)-phenyl-1H-pyrazole (L 1 ) with nitric acid and 5-(4-benzyloxyphenyl)-3-(furan-2-yl)-1H-pyrazole(L 2 ) with hydrochloric acid produced [HL 1 · NO3] (Salt-1) and [HL 2 · Cl] (Salt-2). The structures of Salt-1 and Salt-2 were determined by single crystal X-diffraction. In Salt-1, HL 1 showed [2 + 2] binding of NO3 − ions in the solid state to form dimer architecture with R 1 2 (4) and R 4 4 (14) graph sets. An anion directed one-dimensional anion-assisted helical chain with active participation of the chloride ion and protonated pyrazole via N–H···Cl hydrogen bonding in Salt-2. In addition, the protonated HL 2 molecules interacted with each other through weak C–H···π interactions resulting in the formation of another one-dimensional helical chain.

Some new 3,5-diaryl-1H-pyrazoles were prepared from aryl methyl ketones via Claisen condensation with aromatic esters and followed by cyclization with hydrazine monohydrate. Their structures were confirmed by IR, 1H NMR spectroscopy, mass spectrometry and elemental analysis. The X-ray structure for 3(5)-(4-tert-butylphenyl)-5(3)-(4-methoxyphenyl)-1H-pyrazole (2b) was presented. The results show that compound 2b exists as tautomers I and II, and its molecules are connected by the N–H···N intermolecular hydrogen bonds to form cyclic dimers consisting of the tautomers I and II.

Five diaroylmethanatoboron difluoride derivatives were prepared from aryl methyl ketones via Claisen condensation with aromatic esters and followed by complexation with boron trifluoride etherate. Their structures and spectroscopic properties were studied by elemental analysis, IR, NMR, ESI–MS, UV and fluorescence spectroscopy. The results showed that these boron complexes had strong fluorescent peaks in the 400–500 nm range in chloroform and high quantum yields. The emission peaks for boron complexes containing naphthyl group exhibited considerable red shift as compared to those of containing phenyl group.

Methyl 2-(2,4-dichloro-5-fluorobenzoyl)-3-(pyrimidin-2-ylamino)acrylate has been prepared. Its crystal structure is discussed. The compound crystallizes in the triclinic space group P-1 with a = 11.6259 (7) A, b = 11.8789 (7) A, c = 13.9206 (5) A, α = 68.0250 (10)°, β = 77.5660 (10)°, γ = 62.4950 (10)°, V = 1579.18 (14) A3, Z = 4. There are two independent but chemically identical molecules in the asymmetric unit. The molecules are packed in the crystal structure by weak intermolecular C–H···O and C–H···F interactions.

A complex of Cu(II) with 1-(6-hydroxynaphthalen-2-yl) butane-1,3-dione (HNBD) was synthesized and characterized by elemental analysis, IR, UV and TG-DTA techniques. IR spectra as well as UV-visible absorption measurements indicated that Cu(II) ion was coordinated to the HNBD ligand. The TG-DTA curves showed that the thermal decomposition for Cu(II) complex was a three-steps process. At first, the complex had a mass loss of water molecules at temperature below 134°C, then the thermal decomposition of the anhydrous complex was a two-stage process, which corresponded to the loss of two naphthol molecules and the oxidative decomposition of other organic fragments of ligand. The final decomposition product of the complex was CuO.

The polyoxometalate complexes of ciprofloxacin with HnXW12O40(X=B, Si, P) were prepared from ciprofloxacin hydrochloride and HnXW12O40·nH2O (X=B, Si, P) in aqueous solution, and characterized by elemental analysis, IR spectra and TG-DTA. The IR spectrum confirmed the presence of Keggin-type anion of heteropoly acids and the characteristic functional group of ciprofloxacin after the polyoxometalate complexes are formed. The TG/DTA curves showed that their thermal decomposition was a more-steps process consisting of simultaneous processes involving also Keggin anion. The residue of decomposition is a mixture of WO3and B2O3, SiO2or P2O5, confirmed by X-ray diffraction and IR spectroscopy. And the possible thermal decomposition mechanisms of the complexes are proposed.

A new Co(II) complex 2 with ligand 4,4,4-trifluoro-1-(6-methoxynaphthalen-2-yl) butane-1,3-dione 1 and pyridine are prepared and crystallized from an acetone solution. The obtained red and transparent crystal conforms to the empirical formula of Co(C15H10O3F3)2·(C5H5N)2. It crystallizes in monoclinic, space group C2/c with a = 23.3152(14), b = 12.0225(7), c = 15.3950(10) A, β = 124.1360(10)°, V = 3571.8(4) A3, Z = 4, C40H30CoF6N2O6, Mr = 807.59, F(000) = 1652, Dc = 1.502 g/cm3, μ = 0.564 mm−1, the final R = 0.0466 and wR = 0.1043 for 3901 observed reflections with I > 2σ(I). X-ray structural analysis revealed that the Co(II) atom is coordinated by two oxygen atoms of 1,3-dione ligands 1 and two nitrogen atoms of pyridines, forming a distorted octahedron coordination geometry. A new cobalt complex 2 bis(pyridine)bis(4,4,4-trifluoro-1-(6-methoxynaphthalen-2-yl)butane-1,3-dione) Cobalt(II), Co(C15H10O3F3)2·(C5H5N)2, has been synthesized and characterized by X-ray structure determination. In the complex, the Co(II) atom is coordinated by four oxygen atoms of the β-diketonate ligands and two nitrogen atoms of pyridines, forming a distorted octahedron coordination geometry.

Seven new 3,5-diaryl-1H-pyrazoles were synthesized by the condensation of 1,3-diketones with hydrazine in ethanol, and characterized. The crystal structures for 3(5)-(4-tert-butylphenyl)-5(3)-(4-fluorphenyl)-1H-pyrazole (5) and 3-(4-tert-butylphenyl)-5-(6-methoxy-naphthalen-2-yl)-1H-pyrazole (7) have been determined by X-ray crystal structure analysis. The N–H…N intermolecular hydrogen bonds join the molecules into dimers. The NH proton of 5 is disordered, and its dimer is formed by the tautomers 5a5b or 5b5a. Compound 7 only exists as a 7a tautomer, and its dimer consists of the tautomers 7a7a.

Some new heteropolyoxometalates of large organic cations with molybdotungstosilicic acids (general formula: (CTMA)4SiMoxW12−xO40⋅mH2O⋅nDMF, x=0,2,4,6,8,10,12) were prepared by the reaction of cetyltrimethylammonium bromide (CTMAB,C16H33N(CH3)3Br) with H4SiMoxW12−xO40(x=0,2,4,6,8,10,12) in aqueous solution and recrystallization in DMF, and characterized by elemental analysis, IR spectra,TG-DTA and XRD techniques. The IR spectrum confirms the presence of Keggin structure and organic cations in these compounds, and it is indicated that the stretching vibration of the M-Od, M-Ob-M and Si-Oa becomes more red-shifted when molybdenum is gradually substituted for the tungsten atom. In particular, the thermal decomposition of the heteropolyoxometalates was studied in nitrogen atmosphere. The TG-DTA curves show that their thermal behaviors not only contain the release of water molecule, DMF molecule, CTMA and its fragments but also contains simultaneous collapse of Keggin anion. Their end products of the thermal decomposition are the mixture of WO3, MoO3 and SiO2. And from the final decomposition temperature of view, it is found that the thermal stability of these compounds gradually is decreased when the number of molybdenum atoms is increased.

Claisen condensation of ethyl isonicotinate with different acetophenones gave the corresponding pyridyl-ß-diketones, while the treatment with hydrazine hydrate yielded 3,5-disubstituted-1H-pyrazoles, which then converted 1,3,5-trisubstituted-pyrazole derivatives containing a pyridyl moiety by N-acylation with acyl chloride. The structures of all newly synthesized compounds are established by FTIR, ¹H NMR, mass spectroscopy and elemental analysis, and in the case of compound 2e, analyzed by single-crystal X-ray diffraction further. The anti-microbial activities of the title compounds have been tested by disc diffusion method against Escherichia coli, Staphylococcus aureus, Pyricularia oryzae and Rhizoctnia solani. The results showed that compounds 3c and 4c exhibited good inhibitory activity against all the tested organisms.

A new polyoxometalate (CPFX·HCl)3H4SiW12O40·10H2O was prepared from ciprofloxacin hydrochloride and H4SiW12O40·n H2O in aqueous solution, and characterized by elemental analysis, IR spectra and DTA-TG-DTG techniques. The IR spectrum confirmed the presence of Keggin structure and the characteristic functional group for ciprofloxacin in the compound. The TG-DTA-DTG curves showed that its thermal decomposition was a four-step process consisting of simultaneous collapse of Keggin type structure. The residue of decomposition was the mixture of WO3 and SiO2, confirmed by X-ray diffraction and IR spectroscopy. The decomposition mechanism and non-isothermal kinetic parameters of the polyoxometalate were obtained from an analysis to the TG-DTG curves by the single scanning methods (the Achar method and Coats-Redfern method) and the multiple scanning methods (the Kissinger method, Flynn-Wall-Ozawa method and Starink method). The results indicate that the kinetic equations with parameters describing the thermal decomposition reaction are dα/dt=6.65×106[3(1−α)(2/3)]e(−10495.5/T) with E=87.26 kJ/mol and A=6.65×106 s−1 for the second step, dα/dt=7.01×109(1−α)e(−18770.7/T) with E=156.06 kJ/mol and A=7.01×109 s−1 for the third step, dα/dt=9.77×1043[(1−α)2]e(−88980.0/T) with E=739.78 kJ/mol and A=9.77×1043 s−1 for the fourth step.

A novel bispyrazole derivative 2,6-bis(5-(4-methylphenyl)-1-H-pyrazol-3-yl)pyridine was synthesized and its structure was confirmed by 1H NMR, FTIR, MS techniques and elemental analysis. The binding interactions of BMPP with Cd2+, Co2+, Pb2+ and Cu2+ ions were investigated in MeOH–H2O solution by fluorescence quenching technique at two temperatures (25 and 35 °C). Their quenching constants KSV, binding constants K, binding sites n and thermodynamic parameters (ΔH, ΔG and ΔS) were determined. The results indicated that the metal ions quenched the intrinsic fluorescence of the bispyrazole by forming the bispyrazole–metal complexes and their quenching process was a static quenching mechanism. In addition, the process of interaction was spontaneous and mainly ΔS-driven.

Several new trifluoromethyl-1 H -pyrazoles were prepared by reaction of hydrazine monohydrate with 1,3-diketones. Their structures were confirmed by elemental analysis, IR, 1 H NMR and EI-MS spectroscopy. The anti-microbial activities of the newly synthesized compounds were examined by disc diffusion method against Escherichia coli , Staphylococcus aureus , Pyricularia oryzae and Rhizoctnia solani . All the trifluoromethyl-1 H -pyrazoles exhibited a certain degree of anti-bacterial and anti-fungal activities.

Title compounds (II) are synthesized and tested for their antimicrobial activities against E.

The title molecule, C19H19FO2, exits in the enol form with a dihedral angle of 33.06 (8)° between the two benzene rings. The molecular conformation is stabilized in part by an intramolecular O—H...O hydrogen bond.

In the title compound, C21H16O2, the six crystallographically independent molecules (Z′ = 6) all exist in the enolized form. Strong intramolecular hydrogen bonds are observed: one approximate H-atom-centered O...H...O hydrogen bond, two tautomeric forms O—H...O (three molecules) and O...H—O (two molecules). Only one weak intermolecular C—H...O hydrogen bond between two neighboring molecules is observed in the crystal structure. In addition, eight very weak non-conventional intermolecular C—H...π hydrogen-bonding contacts between molecules are observed.

In the crystal structure of the title compound, C20H16O4, which is in the enol form, the central benzene ring makes dihedral angles of 63.42 (9) and 5.19 (10)° with the phenyl and furan rings, respectively. There is a short strong intramolecular O—H...O hydrogen bond.

In the title compound, C19H14O3, two independent mol­ecules exist in the enol form with normal values for bond lengths and angles. The crystal packing is stabilized by van der Waals forces.

The title compound, C20H16O3, is in the enol form, stabilized by an intra­molecular O—H⋯O hydrogen bond.

The crystal structure of the title compound, C23H22O2, which exists in the enol form, is stabilized by an intra­molecular hydrogen bond. The dihedral angle between the naphthyl ring system and the aromatic ring of the t-BuC6H4 group is 23.50 (10)°.

In the crystal structure the title compound, C(15)H(11)FO(2), the molecule exists in the enol form. It is stabilized by an intra-molecular O-H⋯O hydrogen bond, in which the donor O-H and acceptor H⋯O distances are almost equal. The dihedral angle between the two benzene rings is 22.30 (4)°.