Crystal structure and fluorescence property of antofloxacin

Antofloxacin free base is prepared from antofloxacin hydrochloride by removing hydrogen chloride. Its crystal is obtained by slow evaporation of an acetonitrile-methanol mixed solution. Single-crystal X-ray diffraction reveals that the crystallography belongs to a triclinic PI space group with cell parameters： a = 0. 663 07（13） nm, b = 0. 898 39（18） nm, c = 1. 569 0（3） nm, α = 75.12（3）°,β = 87.92（3）°, γ = 77.57 （3）°. Antofloxacin shows no fluorescence in solution, but the crystalline state emits strong green light at 510 nm under the excitation of 360 nm, indicating a fluorescence enhancement induced by aggregation. It demonstrates that intermolecular packing and interaction in the crystal lead to the improved fluorescence quantum yield. These results provide important intbrmation for the further exploration of the structure-activity relationship of antofloxacin and the development of new drugs.

Ionothermal Synthesis and Fluorescence Property of a Complex Constructed by Seven Nuclear(CH_3COO)_2Co_7(OH)_2] Clusters and 4,4＇-Oxybisbenzoic Acid Ligand

A new 3D cobalt metal-organic framework [C_7H_（13）N_2]_2[（CH_3COO）_2Co_7（oba）_5-（Hoba）_2（OH）_2]·H_2O has been synthesized under ionothermal conditions and characterized by elemental analysis, FT-IR, XRD, and TG. This complex crystallizes in monoclinic system, space group P21/c with a = 19.4499（4）, b = 10.8839（2）, c = 27.7796（5） ？, β = 104.467（2）o, V = 5694.22（19） ？~3, Z = 2, C_（116）H_（92）Co_7N_4O_（42）, M_r = 2626.45, D_c = 1.532 g/cm^3 , F（000） = 2682, μ = 1.085 mm-1, R = 0.0387 and wR = 0.1177. Its structure is characterized as a 3D open framework constructed by seven nuclear clusters [（CH_3COO）_Co_7（OH）_2] and the 4,4？-oxybisbenzoic acid ligand. The used ILs cations are located in the middle of the pore and compensate for the negative charges of framework. Furthermore, its fluorescence property has also been studied.

Hydrothermal Synthesis, Crystal Structure and Fluorescence Property of a Novel Coordination Polymer [Eu_2(C_6H_8O_4)_3(H_2O)_2]_n·n(4,4′-bpy)

A novel coordination polymer [Eu2(C6H8O4)3(H2O)2]n?n(4,4?-bpy) (Mr = 928.51) was synthesized by the hydrothermal reaction of EuCl3?6H2O, adipic acid and 4,4?-bpy, and determined by elemental analysis, IR spectroscopy, thermal gravimetric analysis, single-crystal diffraction and fluorescence property. X-ray analysis reveals that a three-dimensional network has been formed between Eu3+ by carboxyl of adipic acid. The crystal is of orthorhombic, space group Pbcn with a = 21.870(7), b = 7.652(2), c = 19.624(6) ?, V = 3284.1(17) ?3, Z = 4, Dc = 1.878 g/cm3, μ = 3.854 mm-1, F(000) = 1824, R = 0.0345 and wR = 0.0565. The coordination polymer exhibits intensive red light under UV excitation at room temperature, which is attributed to the 5D0→7F2 transition of Eu(Ⅲ) ions.

Synthesis, Single-crystal Structure and Fluorescence Property of a New Boron Compound Based on 2-(2'-hydroxyphenyl)-1H-benzimidazole

A new boron compound [C27H21BN4O3] based on 2-(2?-hydroxyphenyl)-1 Hbenzimidazole has been synthesized and characterized by single-crystal X-ray diffraction, and its crystal crystallizes in the monoclinic system, space group P21/n with a = 9.6544(5), b = 14.1558(8), c = 16.4314(9) ?, β = 97.730°, Mr = 460.29, V = 2225.2(2) ?~3, Z = 4, Dc = 1.374 g/cm~3, μ = 0.74 mm-1, S = 1.051, F(000) = 960, the final R = 0.0643 and w R = 0.1569 for 2233 observed reflections(I > 2σ(I)). The title compound is a B(III) center mononuclear molecule in the asymmetric unit. The typical structural characteristic of the title compound is the methanol group adopting a μ2-bridging mode to link two different adjacent chelating modes though two types of hydrogen bonds to form a one-dimensional supramolecular structure. Additionally, aromatic π-π stacking interactions between adjacent benzimidazolyl groups lead to a three-dimensional network. Furthermore, the stability and fluorescence property revealed the potential applications in the organic photoelectric material.

Synthesis,Crystal Structure,Fluorescence Property and Antibacterial Activity of Two Unprecedented One-dimensional Chain Metal-organic Coordination Polymers: Zn(H-SSA)(Phen)(H_2O)_2and Cu(H-SSA)(Phen)(H_2O)_2

The reaction of 5 sulfosalicylic acid (H 3 SSA) with o phenanthroline (Phen), NaOH, and MCl 2 (M=Zn, Cu) affords Zn(H SSA)(Phen)(H 2O) 2 (1) and Cu(H SSA)(Phen)(H 2O) 2 (2), respectively. Compounds 1 and 2 are characterized by elemental analysis, IR, fluorescence spectra and single crystal X ray diffraction analysis. The X ray diffraction analyses reveal that compounds 1 and 2 are isostructure. The 5 sulfosalicylic acid ligand loses two protons at the sulfo group and carboxylic group during the reaction. The Zn(II) and Cu(II) ions are six coordinated and adopt distorted octahedral geometry, which are surrounded by two N atoms from Phen, two O atoms from two water molecules, one O atom from —SO 3 group and one oxygen from carboxylic group of the other H SSA. Compounds 1 and 2 have unprecedented one dimensional linear chain formed by a repeating mononuclear structural unit, which is bridged by H SSA. The fluorescence intensity of 1 and 2 is stronger than that of Phen and H 3 SSA at 400 nm. The lowest excited single states of these complexes are assigned as mainly Phen localized 1(π,π *). The antibacterial activity test shows that compounds 1 and 2 strongly inhibit the growth of Streptococcus haemolyticus, Straphylococcus aureus and Escherichia coli .

Synthesis,Structures,and Fluorescence Property of a Novel Heterometallic Complex Constructed by Imidazole

A novel heterometallic complex constructed by imidazole ligand,CoZn(C3N2H3)4(1),has been synthesized under hydrothermal conditions.Compound 1 was characterized by IR spectra,thermal analysis,powder X-ray diffraction and single-crystal X-ray diffraction.Single-crystal X-ray diffraction studies reveals that compound 1 is in the tetragonal system,space group I41cd with a=23.4371(5),b=23.4371(5),c=12.4430(7)?,V=6834.9(4)?3,Z=16,C12H12CoN8Zn,Mr=392.60,Dc=1.526 g/cm^3,F(000)=3152,μ=2.381 mm–1,R=0.0323 and w R=0.0789.The CoZn(C3N2H3)4 is one-dimensional heterometallic molecular chains,which are further extended into a 3D open framework.Moreover,the solid-state fluorescence property of the complex has also been investigated at room temperature.

Preparation and Fluorescence Properties of Co-doped Nanocomposite Film Based on Supra Molecular Structure

A novel materials design procedure based on the co-doping of metal nanoparticle and azo dye compound （MNPADC） is developed to improve the properties of functional molecules. The synthesized materials were characterized by transmission electron micrograph （TEM）, ultraviolet-visible absorption spectra （UV-Vis） and fluorescence spectra （FS）. It was found that the fluorescence intensity of methyl orange （MO） was enhanced by 5 times in the aqueous composite system doped with silver nanoparticles whereas it was reduced by 15% and 20% in composite films with co-mixing and coating structures, respectively. The results indicate that the properties of functional molecules can be greatly improved in composite film with supra molecular structure and that the procedure presented here is effective.

Studies on synthesis and fluorescent property of rare earth complexes RE(ABMF)_2AA and copolymers RE(ABMF)_2AA-co-MMA

Four new complexes RE（ABMF）2AA（RE=Sm, Eu, Tb, Dy） were synthesized by the reaction of RECl3·6H2O with acrylic acid（HAA） and 1-（2-furyl）-3-phenyl-1,3-propanedione（ABMF）.The copolymerization of the rare earth complexes with methyl methacrylate was studied by using 2,2-azobis-isobutyronitrile as an initiator.The composition and structure of the four complexes were characterized by elemental analysis, UV-vis and FTIR.The glass transition temperature and molecular weight of the copolymers were determined.Photolu-minescent measurement showed that ligand ABMF could efficiently transfer the energy to Sm^3＋ and Eu^3＋ ions in the complexes and sensitize the luminescence of the rare earth ions, but could not sensitize Tb^3＋ and Dy^3＋ ions.As a result, both Sm^3＋ and Eu^3＋ complexes emitted the characteristic fluorescence of Sm^3＋ and Eu3＋ ions due to the f-f transitions.The four copolymers could emit strong fluorescence of the rare earth ions.

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.

Influence of Blending Temperature on Fluorescence Properties of Silicone Rubber Matrix Eu(TTA)_2(phen)(MA) Composites

A series of fluorescent composites were prepared by blending silicone rubber with Eu(TTA )2(phen)(MA). The influence of mechanical blending temperature on fluorescent intensity of composites and dispersion of rare earth complexes in the SiR matrix were investigated. As for the cured rubber, it is found that its fluorescent intensity is relatively low compared with that of uncured rubber. Low temperature is beneficial to dispersion of Eu(TTA )2(phen)(MA) homogeneously. When the amount of rare earth complexes is low, the fluorescent intensity of composites prepared by mechanical blending method above melting point of Eu(TTA )2(phen)(MA) is much higher than that of composites prepared below melting point.

Synthesis, Crystal Structure and Fluorescent Property of One New Complex [Na_2(2-benzoylbenzoato)_4(Phen)_2(H_2O)_2]·H_2O

One binuclear sodium（Ⅰ） complex [Na2（2-benzoylbenzoato）4（Phen）2（H2O）2]·H2O has been synthesized with 2-benzoylbenzoic acid and 1,10-henanthroline as ligands. The crystal structure was determined by X-ray diffraction. The crystal belongs to the triclinic system with space group P , a = 1.08096（8）, b = 1.09619（8）, c = 1.09740（8） nm, α = 79.0600（1）, β = 71.0450（1）, γ = 62.0540（1）o, V = 1.08533（1） nm3, Dc = 1.421 g/cm3, Z = 2, F（000） = 484, GOOF = 1.036, the final R = 0.0363 and wR = 0.0961. The crystal structure shows that two neighboring sodium（Ⅰ） ions are linked together by two bridging water molecules, and each end position is coordinated with one 1,10-phenanthroline molecule and one 2-benzoylbenzoato to form a binuclear structure. Each sodium（Ⅰ） ion in the molecule is coordinated with five atoms to give a distorted trigonal bipyramid. The fluorescence property of the title complex is also discussed.

Study on the Surface Photovoltage and Fluorescence Properties of N, N-Bis(4-aminopheny)-1, 4 quinonenediimine Doped with H_4SiW_(12)O_(40)

Aniline oligomer composite materials using heteropolyacid H4SiW12O40 as dopant was synthesized, and the effect of the doping concentration on the photoluminescence and surface photovoltaic properties were investigated.

Synthesis and fluorescence properties of Tb(Ⅲ) complexes with pyridine-2,6-dicarboxylic acid derivatives

Two novel ligands named 4-styrylpyridine-2,6-dicarboxylic acid (4-SPDA) and 4-(4-(2-(2, 6-dicarboxypyridin-4-yl)- vinyl)styryl)pyridine-2,6-dicarboxylic acid(DSPDA) and their complexes with Tb(Ⅲ) were synthesized and characterized by infrared spectrometry, 1H nuclear magnetic resonance, elemental analysis and gas chromatograph-mass spectrometry. The ligand synthetic route was optimized. The fluorescence properties of the complex in solid state, in different kind of solvents and in solutions with different pH values were investigated in detail. The results show that the yields of DSPDA and 4-SPDA reach over 78% by Wittig-Horner reaction and other eight pyridine-2, 6-dicarboxylic acid derivatives with different substituents on pyridine ring, and their complexes with Tb(Ⅲ) are also obtained. The fluorescence intensities of the complexes with electron-donating groups are more intense than those of the complexes with electron-withdrawing groups on pyridine ring; fluorescence intensities of the complexes are the strongest in neutral solution (pH=7), and the less the dipole moment of solvent molecule is, the stronger the fluorescence intensity is. It is found that the two ligands (4-APDA and DSPDA) are the good sensitizers for Tb(Ⅲ) ion.

Syntheses, Crystal Structures and Fluorescence Properties of Two Pb(Ⅱ) 1-Naphthoate Complexes

Two new 1-naphthoate-based Pb（Ⅱ） complexes, [Pb（phen）（NA）2]n 1 and [Pb（bpp）（NA）2]n 2 （NA = 1-naphthoate, phen = 1,10-phenanthroline, and bpp = 1,3-bi（4-pyri- dyl）propane）, were hydrothermally synthesized and structurally characterized. 1 is of monoclinic system, space group C2/c with a = 28.114（3）, b = 10.9601（10）, c = 8.6843（8） , β = 93.3760（10）°, V = 2671.3（4） 3, Dc = 1.814 g/cm3, Mr = 729.73, Z = 4, F（000） = 1416, μ = 6.360 mm-1, the final R = 0.0346 and wR = 0.0948 for 2184 observed reflections with I 〉 2σ（I）. Complex 2 crystallizes in monoclinic, space group C2/c with a = 26.491（2）, b = 8.7773（6）, c = 27.893（2） , β = 113.3020（10）°, V = 5956.8（8）3, Dc = 1.668 g/cm3, Mr = 747.78, Z = 8, F（000） = 2928, μ = 5.706 mm-1, the final R = 0.0211 and wR = 0.0493 for 3677 observed reflections with I 〉 2σ（I）. Both complexes present one-dimensional （1-D） zigzag chains extended by anionic NA linkers for 1 and bridged by neutral bpp connectors for 2, which are further aggregated into 2-D supramolecular networks by interchain π···π stacking interactions. In addition, the two solid-state complexes exhibit different strong emissions at room temperature, suggesting their potential applications as fluorescence materials.

Fluorescence Properties of Porphyrin Dimers Incorporating an Anhydride Linker

A preliminary study on a novel free base porphyrin dimer and a zinc prophyrin dimer by comparing their fluorescence properties with those of the corresponding monomers is presented. The fluorescence intensity of the free base dimer is five times higher than that of the monomer, but the fluorescence intensity of the zinc porphyrin dimer is nearly similar to that of the zinc porphyrin monomer. The emission spectra show that energy transfer occurs between the two units.

Fluorescence Quantum Efficiency Enhancement in CaWO_4:Eu^(3+),Na^+ Nanocrystals by Tridoping with F^- Ions

We demonstrated that tridoping with F- ions is an effective way to improve the fluorescence quantum efficiency of CaWO4：Eu3＋,Na＋ nanocrystals. F--tridoped samples with different F- concentrations were synthesized by a hydrothermal process. The fluorescence spectra and decay curves were measured at room temperature. The fluorescence intensity of F--tridoped samples is about 3 times that for the non F--doped sample. The fluorescence quantum efficiency can be enhanced by 21% when the atomic ratio of F to W was 0.7.

A New Cadmium(Ⅱ) Coordination Polymer Extended through Hydrogen Bonds and π-π Stacking Interactions: Synthesis and Photoluminescence Property

A new coordination polymer, {[Cd(OPY)(tdc)(HO)]·H2 O}n(OPY = 4,4?-(oxybis(4,1-phenylene))dipyridine, H2 tdc = thiophene-2,5-dicarboxylic acid), has been synthesized hydrothermally based on a V-shaped ligand OPY. The structure was fully characterized by elemental analysis, FT-IR spectroscopy, and X-ray single-crystal diffraction analysis. In1, two OPY ligands and one water molecule acted as terminal ligands coordinating to Cdcation to form [Cd(OPY)HO]units, which are then linked by tdc2-ligands to generate a one-dimensional chain. Every two adjacent chains linked by extensive O–H···O hydrogen bonds constitute one-dimensional double-chains, and such chains are extended into two-dimensional layers via O–H···N hydrogen bonds. These layers are further connected to form a three-dimensional supramolecular architecture via π-π stacking interactions. In addition, the thermal stability and solid state fluorescence property of 1 were also investigated.

Synthesis and Fluorescent Property of Europium Ternary Complex-MMA Copolymer

Under the mild condition a new ternary rare earth complex Eu （ DBM ）2MA · 2H2O [ DBM： C6H5COCHCOC6H5; MA： CH2C（CH3）COO^- ] was synthesized by the reaction of EuCl3 with dibenzoylmethane and methacrylate in alcohol. A new bonded copolymer Eu（DBM）2MA-MMA was prepared by copolymerization of the Eu（DBM）2MA·2H2O complex with methyl methacrylate（MMA） monomer using AIBN as an initiator. The composition, structure and fluorescence properties of the complex and copolymer were characterized by means of elemental analysis, complex titration, IR, UV-VIS and fluorescent spectra. The thermal stability, glass temperature and average molecular weight of the copolymer Eu（DBM）2MA-MMA were determined by TG-DTA, DSC and GPC, respectively. The research results show that both of the ternary rare earth complex and the copolymer can emit strong Eu（Ⅲ） fluorescence at 613 nm.

Synthesis,Crystal Structure and Luminescent Property of a 2-D Hybrid Constructed from [Pb_2I_4] Subunits

A novel organic-inorganic hybrid compound, [Pb2I4（bipy）], （bipy = 4,4′-bipyridine）, was synthesized by self-assembly and its structure was determined by X-ray crystallography method The crystal belongs to the monoclinic system, space group P2 1/c with α = 4.4691（9）, b = 15.385（3）, c = 14.136（3） A, β = 93.75（3）°, V= 969.9（3） A^3, Mr = 1078.16, Dc= 3.692 g/cm^3, F（000） = 916, μ = 23.688 mm^-1, Z = 2, the final R = 0.0395 and wR = 0.0887 for 1557 observed reflections with I 〉 2σ（I）. The title compound presents a two-dimensional layer-like structure constructed from [PbI5N] octahedron and bis-bridging ligand 4,4′-bipyridine. The fluorescence of the title compound is also discussed in this communication.

Syntheses, Crystal Structures and Fluorescence Properties of Two Triazolyl Derivatives with Biphenyl Links

Two novel triazolyl derivatives with biphenyl links, namely 4,4-bis（1,2,4-triazol-1-ylmethyl）biphenylene 1 and 4,4-bis（3,5-dimethyl-1,2,4-triazol-1-ylmethyl）biphenylene 2, have been synthesized and structurally characterized by single-crystal X-ray diffraction. Compounds 1·H2O·HCl and 2·2H2O·2HCl crystallize in the monoclinic system with space group C2/c and P21/c, respectively. The dihedral angles of the two phenyl rings are 30.26（6）° in 1·H2O·HCl, while co-planar （0.00（7）°） in 2·2H2O·2HCl. In 1·H2O·HCl, the N-H…O hydrogen bonds link 1 to form chain-like structures which are further connected by O-H…Cl, C-H…Cl, C-H…O and π-π supramolecular interactions. The hydrogen bonds of O-H…Cl in 2·2H2O·2HCl provide distinguishing P/M helical chains along the b axis, and these chains are further connected by N-H…O hydrogen bonds to generate a 2D structure. Compounds 1 and 2 in methanol solution show much stronger emission bands at 319 nm than biphenyl at 316 nm under excitation at 260 nm.