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,luminescent properties,and theoretical study of novel Sm^(3+) and Dy^(3+) complexes containing β-diketone and 1,10-phenanthroline

Two new ternary complexes of 1-（2-thienyl）-3-（p-phenylethynylphenyl）-1,3-propanedione（HTPP） and 1,10-phenanthroline（phen） with Sm^3＋ and Dy^3＋ were synthesized.The composition of the ternary complexes was characterized as Sm（TPP）3phen and Dy（TPP）3phen,respectively,by infrared（IR） spectra,chemical analysis,elemental analysis,and thermodynamic analysis.At room temperature,under UV light excitation,the Sm^3＋ and Dy^3＋ complexes exhibit characteristic emissions of the central ions.It is found that the fluorescence intensity of Sm（TPP）3phen is stronger than that of Dy（TPP）3phen.In order to explain this phenomenon,an accurate quantum chemistry calculation was carried out,and the result is in good agreement with the experiment data.

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.

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.

Synthesis and Photophysical Properties of Dy^(3+) and Gd^(3+) Polymeric Complexes with Functionalized Polybenzimidazole Containing β-Diketone Side Group

The polymeric ligand PBIa （functionalized polybenzimidazole containing β-diketone side group） was successfully synthesized via the reaction of polybenzimidazole （PBI） with 3-Br-acetylacetone in DM SO solvent using Nail as the deprotonation reagent. Its corresponding polymeric complexes of Dy^3＋ and Gd^3＋ were prepared and characterized by FT-IR, ^1H NMR, molar conductance measurements, and thermal analysis. The photoluminescence properties and the probable mechanism of the Dy and Gd complexes were studied. The measurement and analysis of the thermal properties showed that these were thermal stable.

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.

Design, Synthesis, Crystal Structure and Photoluminescence Properties of Four New Europium (III) Complexes with Fluorinated β-Diketone Ligand

The strong photoluminescence properties of europium complexes with organic ligands attracted the attention of many researchers and found a wide range of uses in medical, industrial and biological fields. In this article, four new Tetrakis europium complexes 3a, 3b, 3c and 3d have been prepared using 1-phenyl-4,4,4-trifluoro-1,3-butenedionato ligand and pyridinium, bipyridinium, piperazinium and piperidinium counter cations. These complexes have been characterized by negative FAB-mass. The crystal structures of 3a, 3b, 3c and 3d were determined by single crystal X-ray diffraction analysis. The complex 3a crystallized in monoclinic form, space group P21/n with four molecules in the unit cell. The complex 3b crystallized in monoclinic form, space group P2/n with two complex molecules in the unit cell. The complex 3c crystallized in monoclinic form, space group C2/c with sixteen molecules in the unit cell. The complex 3d crystallized in monoclinic form, space group P21/n with four complex molecules in the unit cell. The complex 3a has 1,2-alternative structure, 3b has 1,3-alternative structure, 3c has cone like structure and 3d has partial cone like structure. The photoluminescence properties of these complexes have been evaluated. Strong red emissions were observed in all four complexes due to 5D0 → 7F2 transition of Europium (III) ions under UV excitation. Four β-diketone ligands acted as strong antenna ligands and transferred the absorbed energy to europium (III) ion effectively;consequently strong red luminescence was observed.

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.

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.

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.

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.

Synthesis and Physico-Chemical Characterizations of Novel Hydrazone Ligands and Their Metal Complexes against Hormone-Dependent and Independent Cancers

This work deals with the synthesis and physicochemical characterizations of a new group of novel retinoidal ligands and their metal complexes. Their in vitro anti-proliferative activities have shown that ligand L1 is effective against human breast cancer BT-20 and MCF-7 cell lines. At the same time, compound L2 exerts its effect on human prostate cancer PC-3 and human breast cancer MDA-MB-231 and MCF-7 cell lines respectively. The retinoid ligands exert their pleiotropic action toward retinoic acid receptors (RARs) than their metal complexes but all compounds exhibit concentration-dependent.

Structures and magnetism of dinuclear Co complexes based on imine derivatives

This study presents the synthesis of three dinuclear cobalt complexes based on three imine derivatives:bis-[4-(2-pyridylmethyleneamino)-phenyl]thioether(L1),bis-[4-(2-pyridylmethyleneamino)-phenyl]ether(L2),and bis-[4-(2-pyridylmethyleneamino)-phenyl]methane(L3).Single-crystal X-ray diffraction analysis reveals that the complexes[Co_(2)(L1)3](ClO_(4))4·2CH_(3)CN(1),[Co_(2)(L2)3](ClO_(4))4·2CH_(3)OH(2),and[Co_(2)(L3)3](ClO_(4))4·2CH_(3)OH(3)all exhibit a dinuclear structure.Magnetic test results show that complex 3 exhibited irreversible SCO behavior induced by loss of solvent at 300 K,with the average Co-N bond length increasing from 0.2139(3)to 0.2153(3)nm.Meanwhile,the desolvated complex 3 exhibited paramagnetic behavior similar to that of complexes 1 and 2.Variable-temperature UV-Vis spectroscopic studies also indicate that complex 3 undergoes a solvent-loss-induced spin-state transition.CCDC:2347354,1(120 K);2347355,2(120 K);2347356,3(120 K);2347357,3(400 K).

Aerobic Enantioselective Epoxidation of Styrene Analogues Induced by (β-Diketone)-iron( Ⅲ ) Complex

Tris（d,d-dicampholylmethanato） iron （Ⅲ） complex, Fe（dcm）3, was found to be an excellent catalyst for asymmetric oxygenation of styrene analogues into the corresponding epoxides. Good chemical yields and higher enantioselectivity were obtained with combined use of molecular oxygen and an aldehyde at 30℃, Some factors influencing enantioselectivity were discussed.

Catalytic Effect of Transition Metal Complexes of Triaminoguanidine on the Thermolysis of Energetic NC/DEGDN Composite

The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and diethylene glycol dinitrate,has been investigated.Extensive characterization of the resulting energetic composites was carried out using scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and differential scanning calorimetry(DSC).Isoconversional kinetic analysis was performed to determine the Arrhenius parameters associated with the thermolysis of the elaborated energetic formulations.It is found that TAG-M complexes have strong catalytic effect on the thermo-kinetic decomposition of NC/DEGDN by decreasing the apparent activation energy and significantly increased the total heat release.The models that govern the decomposition processes are also studied,and it is revealed that different reaction processes are accomplished by introduction metal complexes of triaminoguanidine.Overall,this study serves as a valuable reference for future research focused on the investigation of catalytic combustion features of solid propellants.

Subtraction of liposome signals in cryo-EM structural determination of protein-liposome complexes

Reconstituting membrane proteins in liposomes and determining their structure is a common method for determining membrane protein structures using single-particle cryo-electron microscopy(cryo-EM).However,the strong signal of liposomes under cryo-EM imaging conditions often interferes with the structural determination of the embedded membrane proteins.Here,we propose a liposome signal subtraction method based on single-particle two-dimensional(2D)classification average images,aimed at enhancing the reconstruction resolution of membrane proteins.We analyzed the signal distribution characteristics of liposomes and proteins within the 2D classification average images of protein–liposome complexes in the frequency domain.Based on this analysis,we designed a method to subtract the liposome signals from the original particle images.After the subtraction,the accuracy of single-particle three-dimensional(3D)alignment was improved,enhancing the resolution of the final 3D reconstruction.We demonstrated this method using a PIEZO1-proteoliposome dataset by improving the resolution of the PIEZO1 protein.

Catalytic Asymmetric Cyclopropanation using a New Chiral β-Diketone Cu (Ⅱ) Complex as a Catalyst

A new chiral β-diketone Cu (Ⅱ) catalyst was synthesized and used for the asymmetric cyclopropanation of styrene with diazoester. A high optical yield (~90%) was achieved. The effect of the structure of substrate on the enantioselectivity was studied. Both chendcal yield and optical yield being reduced when the steric bulky substrate was employed. The reaction mechanism and the chiral model of the transition state are under fufther investigation.

Two novel Cu(Ⅰ)complexes based on diimide and bisphosphine ligands:synthesis,crystal structure and spectroscopic properties

Two Cu(Ⅰ)complexes[Cu(Bphen)(dppBz)]ClO_(4)·2CH_(3)OH(1)and[Cu_(2)(Bphen)_(2)(dpppda)]BF_(4)(2){Bphen=4,7-diphenyl-1,10-phenanthroline,dppBz=1,2-Bis(diphenylphosphino)benzene,dpppda=N1,N1,N4,N4-tetrakis[(diphenylphosphino)methyl]-1,4-benzenediamin}were synthesized using a one-pot method.X-ray crystallography was used to elucidate their crystal structures and photophysical properties.A series of characterization tests including elemental analysis,NMR,FT-IR,UV-Vis absorption spectroscopy,fluorescence spectroscopy,thermal gravimetric analysis and terahertz time-domain spectroscopy(THz-TDS)were used to further investigate their properties.The results show that complex 1 structure is mononuclear containing two solvent molecules per unit cell,while complex 2 structure is binuclear containing two metal centers per unit cell.According to photophysical properties and density functional theory(DFT)calculations,their luminescence properties can be attributed to metal-to-ligand charge transfer(MLCT).Both complexes have a unique stability,which is confirmed by thermal gravimetric analysis.

Novel Iridium Complex with Carbazol-2-yl-β-diketone Derivative:Low-energy Excitation and Red Electrophosphorescent Devices

A novel iridium-complex,（BPPBI） 2 Ir（2-TFDBC）[BPPBI=2-（biphenyl-4-yl）-1-phenyl-1H-benzo[d]imidazole,2-TFDBC=1-（9-ethyl-9H-carbazol-2-yl）-4,4,4-trifluorobutane-1,3-dione],was synthesized,and its structure and component were confirmed by 1 H NMR and element analysis,respectively.UV-Vis absorption and photoluminescent（PL） spectra of（BPPBI） 2 Ir（2-TFDBC） in dichloromethane were investigated.The Ir-complex exhibited a long wavelength excitation of 470 nm,i.e.,low-energy excitation.So,it is a promising candidate for phosphorescent probe and PL material.（BPPBI） 2 Ir（2-TFDBC）-based electroluminescent devices,ITO/MoO 3（10 nm）/NPB（80 nm）/CBP：x（BPPBI） 2 Ir（2-TFDBC）（20 nm）/TPBi（45 nm）/LiF/Al,were fabricated,where x（%） was of 4% or 8% doping concentration（mass fraction）;ITO=indium tin oxides;NBP=N,N＇-bis-（1-naphthalenyl）-N,N＇-bis-phenyl-（1,1＇-biphenyl）4,4＇-diamine,CBP=4,4＇-bis（N-carbazolyl）-1,1＇-biphenyl,TPBi=1,3,5-tris（1-phenyl-1H-benzimidazol-2-yl）benzene.The devices showed a red emission of 620 nm.The maximum current efficiency and brightness were 1.7 cd/A and 4063 cd/m 2 for a device of 8%（mass fraction） doping level,respectively.The moderate luminous efficiency was due to the inadequate energy transfer from the host material to the guest material.