Mass Transport of β-Diketonate Precursors for MOCVD of YBa_2Cu_3O_(7-δ) High T_c Superconducting Thin Films

Mass transport of Y(dpm)2 Ba(dpm)5· OH· 2Ho and Cu (dpm)2 by a carrier gas(argon) was theoretically considered and experimentally studied as a function of the system with operating parameters including temperature, carrier gas flow rate and system pressure. The experimental results are in a good agreement with the theoretical prediction. The mechanism of mass transport of these organometallic precursors and their use for YBCO film stoichiometry control and reproducibility are discussed.

UV-Vis Spectrum and the Third-order Nonlinear Optical Properties of the Chiral Camphorderived β-diketonate Platinum Complexes

UV-Vis spectrum and the third-order nonlinear optical properties of the chiral camphor-derived β-diketonate have been studied at the B3LYP/6-31G＊ level. The results showed that the introduction of electron-drawing group -CF3 and -C3F7 on β-diketonate made the strongest absorption peak red-shift and the lowest energy absorption blue-shied. Introduction of -OC2H5 on the benzene or pyridine ring made the lowest energy absorption blue-shift. When the -C2H3 was introduced on the benzene or pyridine ring, the lowest energy absorption was red-shifted. Introduction of electron-donating group on β-diketonate can enlarge their nonlinear optical properties. On the contrary, the introduction of electron-drawing group dropped it down.

Quadruple-stranded Eu-helicate Assembled from Bis-β-diketonate： Its Stability Towards Metal Ions

Herein, we reported the synthesis and investigation of highly luminescent quadruple-stranded helicate （C6H 16N）4[Eu2（MBDA）4]2·3 C4H10O.4C2H 3N（ 1-Eu） [H2M B DA=N-methyl-4,4＇-b i s（4,4,4-tri fl uoro-1,3-dioxob utyl）di- phenylamine] for its stability toward metal ions in the solution. The material was characterized via X-ray crystallo- graphic technique, Fourier transform infrared（FTIR） spectroscopy and electrospray ionization quadrapole time-of- flight（ESI-TOF） mass spectrometry. The results on the luminescence quantum yields clearly demonstrate that the ligand can effectively sensitize the luminescence of the Eu3＋ ions（φoverall=15%）. Upon the addition of different metal ions（i, e., Ag＋, Cd2＋, Zn2＋, Fe3＋, A13＋ and Ni2＋） to the CH3CN solution of compound I-Eu, the emission intensities of Eu3＋ ions at 612 nm were affected to some extent, which could be attributed to the presence of ion exchanges between Eu3＋ ions and the metals ions, and the result was confirmed by ESI-TOF mass spectrometry.

Difluoroboron β-diketonate dye with intense red/near-infrared fluorescence in solutions and solid states

Difluoroboronβ-diketonate(BF2bdk)complexes have attracted much attention due to their outstanding photophysical properties.However,BF2bdk with near-infrared fluorescence usually suffer from emission quenching in solid state due to theπ-πstacking in aggregation.Herein,we report a BF2bdk dye exhibiting donor-acceptor(D-A)structure with the difluoroboron moiety acting as the electron acceptor and the aminonaphthalene as the electron donor.It processes intense molar extinction coefficient,large Stokes shift and strong fluorescence in red/NIR region in both solution and aggregations.It was used for NIR imaging in living cells.

Investigation of the Solar Cells with Films of Porous Silicon and <i>β</i>-Diketonates

The experimental results of a research of the solar cells parameters covered with films InxSnyOz, and solar cells covered with films, obtained by dispersion of alcoholic solutions of three-chloride Indium acetyl acetonate of aluminum are represented. The spectral dependencies of reflection factor and open circuit voltage of the film-covered solar cells are obtained. The conditions of deriving and properties of porous silicon and parameters of the solar cells with films of porous silicon and covers, forming a potential barrier, are investigated. It is shown that for optimum parameters of films deriving the solar cells with efficiency 15.8% is possible.

Copper-Catalyzed C-C(O)C Bond Cleavage of Monoalkylated β-Diketone: Synthesis of α,β-Unsaturated Ketones

A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K3PO4) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .

Synergistic extraction of zinc from ammoniacal solutions using β-diketone mixed with CYANEX923 or LIX84I

The extraction behaviors of zinc from ammoniacal solutions were investigated using β-diketone （HA） and their mixtures with CYANEX923 or LIX84I. The effects of pH, total ammonia concentration, extractant concentration, anion species and temperature on zinc extraction were examined. The synergistic mechanism was discussed with regard to the structure of extractant and the extracted zinc complexes. It is found that the increase of total ammonia concentration and pH inhibits zinc extraction for all extraction systems due to the formation of zinc ammine complexes in aqueous phase. This effect of HA with CYANEX923 is evidently smaller than that of HA with LIX84I or HA alone system. Effect of anion species on the zinc extraction by HA with CYANEX923 can be neglected, but this effect of HA alone and the mixture of HA with LIX84I decreases in the order of （NH4）2SO4 〉 NH4NO3 〉 NH4Cl.

3,6-Bis-β-Dicarbonylsubstituted Carbazoles Bearing N-Spacers and Their Eu(III) Complexes as Immunofluorescent Labelling Agents

New reagents for immunofluorescence analysis of carbazole series containing fluorinated β-dicarbonyl fragments and carboxylic substituent groups separated by spacers of different lengths from the light-gathering carbazole scaffold have been developed. The markers in complex with Eu3+ ions possess stability in the aqueous phase, intense and prolonged luminescence (τ 550 - 570 μs) with characteristic emission maxima in the region of 615 nm and excitation wavelengths in the region of 380 - 390 nm, which distinguishes them from most of the analogs used. In the study of marker conjugation with streptavidin, a reagent containing 4 - 5 europium labeling complexes based on spacer-containing carbazole tetraketone was obtained. The marker-doped silicate nanoparticles exhibit intense and long-lived luminescence in the characteristic region.

Synthesis and fluorescent properties in complexes of Eu( Ⅲ), Tb( Ⅲ), and Sm( Ⅲ) with β-diketone and 2,2′-bipyridine

Three new rare earth ternary complexes, RE(PB)_3bpy (RE=Sm^(3+) , Eu^(3+) , and Tb^(3+) ), were synthesized by the reaction of 1-(p-phenylethynyl- phenyl)-1,3-butanedione (HPB) and 2,2′-bipyridine (bpy) with rare earth chloride RECl_3 , respectively, in alcohol solution. The compositions were characterized by means of infrared (IR) spectra, chemical analysis, elemental analysis, and thermodynamic analysis. Luminescent properties of the three complexes were studied. At room temperature, under UV light excitation, the Sm^(3+) , Eu^(3+) , and Tb^(3+) complexes exhibit characteristic emission of the central ions. The fluorescence spectra show that the fluorescence emission intensity of Eu^(3+) complex is the strongest. The narrow strongest emission band of Eu^(3+) complex is considered to be a valuable material with bright red fluorescence.

Synthesis and luminescence properties of rare earth ternary complexes consisting of Tb(Ⅲ), β-diketones and 1,10-phenanthroline (phen)

In order to study the luminescent properties of ternary rare earth complexes with fl-diketone ligand, three new β-diketone ligands, 1-phenyl-3-（p-phenylethynylphenyl）-1,3-propanedione（HPPP）, 1-（2-thienyl）-3-（p-phenylethynylphenyl）-1,3-propanedione （HTPP） and 1-（2-furyl）-3-（p-phenylethynylphenyl）-1,3-propanedione （HFPP）, were synthesized by Sonogashira coupling reaction and Claisen condensation. Three new ternary rare earth complexes, TbL3phen （L = PPP, TPP, or FPP）, were synthesized by the reaction of rare earth chloride TbCl3,1,10-phenanthroline （phen） with HPPP, HTPP, or HFPP respectively, in alcohol solution. The compositions were characterized by means of elemental analysis, chemical analysis, and IR spectra. Luminescent properties of the three new complexes have been studied. The results show that the ternary Yb（Ⅲ） complexes only emit the weak fluorescence of the Tb（Ⅲ） ion, which reveals the triplet state energy of the ligands does not match well with the excited state vibrating energy of Tb^3＋ ion.

Synthesis,fluorescence properties of Eu(Ⅲ) complexes with novel carbazole functionalized β-diketone ligand

A novel carbazole functionalized β-diketone, methyl 6-（9-ethylcarbazole-3-yl）-oxoacetyl-2-pyridinecarboxylate （MEP）, and its corresponding binary Eu（III） complexes Eu（MEP）y2H2O and ternary complex Eu（MEP）aPhen with 1,10-Phenanthroline （Phen） were prepared. The ligand was characterized based on elemental analysis, FT-IR, and ^1H NMR, and the complexes were characterized with elemental analysis, FT-IR and thermogravimetric and differential thermal analysis （TG-DTA）. The investigation of fluorescence properties of the complexes Eu（MEP）3·2H2O and Eu（MEP）3Phen showed that the Eu（III） ion could be sensitized efficiently by the ligand to some extent, in partitular, in the ternary system, the secondary ligand Phen acting as a light-harvesting center was involved in the highly efficient energy transfer process, and the emission was stronger than the binary complex. In addition, the introduction of the carbazole moiety enlarged the n-conjugated system of the ligand and enhanced the luminescent intensity of the complexes.

A mild,simple and efficient method for selectiveα-monobromination of 1,3-diketones and β-ketoesters using pyridinium bromochromate

Pyridinium bromochromate has been found to be a highly efficient and selective reagent for the α-monobromination of 1,3- diketones and β-keto-esters in the absence of base, Lewis acid, or other catalyst. The products were formed in high to excellent yields under mild reaction conditions and in short reaction times.

β-Diketones at Water/Supercritical CO2 Interface： A Molecular Dynamics Simulation

The structural and dynamical properties of hexafluoroacetylacetone(HFA) and acetylacetone(AA) at the water/supercritical CO2(Sc-CO2) interface at 20 MPa and 318.15 K are investigated by molecular dynamics simulations.The TIP3P potential is used for water and the EPM2 model is for CO2.The water phase and SC-CO2 phase form a distinct immiscible liquid-liquid interface.The two chelating molecules show interfacial preference.Comparatively,the AA molecules show somewhat more preference for interfacial region,whereas the HFA molecules are preferably near the Sc-CO2 phase.The orientational distribution of the β-diketone molecules and the radial distribution functions between β-diketones and solvents are obtained in order to study the microscopic structural properties of the β-diketones at the water-SC-CO2 interface.It is found that the translational diffusion and rotational diffusion of HFA and AA are obviously anisotropic and decrease as the β-diketone molecules approach the interface.The anisotropic dynamic behavior for the solute molecules is related to the corresponding structural properties.

Synthesis and luminescence properties of rare earth ternary complexes consisting of Eu(III), β-diketones and 1,10-phenanthroline

Three novel β-diketones （HPPP, HTPP, and HFPP） ligands were synthesized by Sonogashira coupling reaction and Claisen condensation. The structure of β-diketones was confirmed with elemental analysis, IR, NMR and MS spectra. Three new ternary complexes consisting of Eu（Ⅲ）, β-diketones, and 1,10-phenanthroline（phen） were synthesized and characterized as TbL3phen （L=PPP, TPP, FPP） with elemental analysis, chemical analysis, and IR spectra, and their luminescence properties were studied.

Asymmetric Intramolecular Cyclopropanation Induced by (β-Diketone)-copper Complex

Asymmetric intramolecular cyclopropanation of allylic diazoacetate was investigated using a chiral (β-diketone)-copper complex as catalyst, excellent yield and enantioselectivity were achieved. Some factors influencing enantioselectivity were discussed.

A NOVEL TITANIUM COMPLEX WITH LINKED β-DIKETONATO-INDENYL LIGAND FOR CATALYTIC SYNDIOSPECIFIC POLYMERIZATION OF STYRENE

A novel ligand (3), in which the indenyl group is linked to a β-diketone moiety through a three-carbon bridge, andits titanium complex (4) were synthesized. The titanium complex was employed as a metallocene analog with co-catalystmethylaluminoxane (MAO) in catalytic syndiospecific polymerization of styrene to give highly syndiotactic polystyrene(s-PS, 96%-97%). Polymerization temperature (T_p) strongly influenced the catalytic activity and syndiotacticity of theproduced PS. The activities of catalyst 4 increase from 1.84×10~6 to 3.26×10~6 gPS/molTi·h with the increase of T_p from60℃ to 80℃ and the syndiotacticities of the produced s-PS also increase slightly. Then, both the catalytic activity and thesyndiotacticity of PS decrease at T_p of 90℃.

A Scope Study of Condensation of1,3-Diketones with Diethyl Acetonedicarboxylate

ＡＳｃｏｐｅＳｔｕｄｙｏｆＣｏｎｄｅｎｓａｔｉｏｎｏｆ１，３－ＤｉｋｅｔｏｎｅｓｗｉｔｈＤｉｅｔｈｙｌＡｃｅｔｏｎｅｄｉｃａｒｂｏｘｙｌａｔｅＺＨＯＮＧＺｈｅｎ－ｑｉ，ＴＡＮＧＨｕｉ－ｔｏｎｇ，ＺＨＡＮＧＰａｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓ...

SYNTHESIS AND MESOMORPHIC PROPERTIES OF FISHBONE-LIKE LIQUID CRYSTALLINE POLYSILSESQUIOXANES——Ⅰ. FISHBONE-LIKE, β-DIKETONE-BASED LIQUID CRYSTALLINE POLYSILSESQUIOXANES AND THEIR COPPER COMPLEXES

Two kinds of fishbone-like, β-diketone-based liquid crystalline polysilsesquioxanes(FBDKLCP'S), homopolymeric (H-FBDKLCP) and copolymeric (C-FBDKaLCP) have been first synthesized via the hydrosilylation reaction of a vinyl-terminated β-diketone with the homopolymeric ladderlike polyhydrosilsesquioxane (LPHSQ) and random copolymethylhydrosilsesquioxane (LRPMHSQ) respectively. These new kinds of FBDKLCP with M of 10~4 is thermotroic liquid crystalline polymer and its clearing temperatures T_i's and mesophase range △T's are much higher than those of the corresponding comb-like β-diketone liquid crystalline polysiloxane (DKLCP) by about 200℃. Similar results have been observed with the comparison of the two different structure Cu-coordinating compounds The significant increases in T_((?))'s and △T's of the FBDKLCP and Cu-FBDKLCP are mainly attributed to the great rigidity of the ladderlike polysilsesquioxane backbone.

SYNTHESIS AND MESOMORPHIC PROPERTIES OF PALLADIUM CHELATES OF LIQUID CRYSTAL POLYSILOXANE WITH β-DIKETONE-BASED SIDE CHAINS

A new type of palladium chelate of β-diketone-based side chain liquid crystal polysiloxane (Pd-DKLCP) has been synthesized by chelation reaction of palladium dichloride with polymeric ligand, β-diketone polysiloxane (DKLCP), using THF as solvent at R.T.. The Pd-chelation results in greatly increasing the phase transition temperature T_K and the enthalpy change △H_K from crystal to liquid crystal state and making the temperature range of LC state △T(△T=T_(Cl)-T_K) widened. All these chelates Pd-DKLCP's do not show T_(Cl) until decomposition at 205℃. It is noteworthy that the Pd-chelation can exert more positive effect on the mesomorphic behaviour of the polymer ligand than the counterpart Cu-DKLCP does. It is probable due to the bigger size of disc-like mesogen formed from β-diketone and Pd^(+2) ion with 4d orbital.

SYNTHESIS AND PROPERTIES OF METAL COMPLEXES OF β-DIKETONE BASED SIDE CHAIN LIQUID CRYSTAL POLYSILOXANE

A new type of metal coordinated liquid crystalline polymers has been synthesized by complexation of metal ions with β-diketone based side chain liquid crystal polysiloxane (DKLCP). The complexation of copper ions with DKLCP greatly increases the phase transition temperature T_k from crystalline state to liquid crystalline state and T_(cl) from LC to isotropic state and makes the range of phase transition ΔT (ΔT=T_(cl)-T_k) widened. These complexes are soluble in common organic solvents. However, the incorporation of europium ions into DKLCP molecules gives rise to reduction in liquid crystallinity and crosslinking in some cases. The DKLCP coordinated with suitable amount of Eu ions can show good liquid crystallinity and fluorescent property.