SYNTHESIS, MOLECULAR STRUCTURE, SPECTRA AND ELECTROCHEMISTRY OF TWO GEOMETRIC ISOMERS OF TETRAKIS(2-ANILINOPYRIDINATO) DIRHODIUM*

Two gemetric isomers of new dirhodium complex, Rh_2(ap)_4(ap=2-anilinopyridinato),have been synthesixed and isolated. The isomers were characterized by a single-crystal X-ray diffraction analysis. They are 4,0 gemeter (compound 1) and 2,2 trans geometer (compound 2).The radical cations of 1and 2are ESR active. The ESR spectrum of 1+ions, reports that the order of g value is g_⊥>g_e>∥,and the value of g is split into doublet at 77K. This result is consistent with a calculation of the self-consistent-charge discrete variational method. It is shown conclusively that the odd electron is localized on one rhodium. ion with no bound axial ligand, thus giving the first example of true Rh(Ⅱ )—Rh(Ⅲ) complex. The ESR spectrum of 2+ shows g split into a 1:2:1 trilet .In addition, cyclic voltammetry and ESCA of two isomers were detrmined and analyxed. The results indicate that Rh_2(ap)_4 is not only chemically reactive but also sensitive to photochemical oxidation, thus having a wide application in future.     

Fluorescence Quenching of a Novel Eu(Ⅲ) Coordination Compound for the Detection of Trace Amounts of Water: Synthesis,Structure and Photoluminescent Property

A novel luminescent coordination compound Eu(TTA)_3(DEDAF)(1, TTA = 1,1,1-trifluoro-3-(2-thenoyl)acetone, DEDAF = 9,9-diethyl-4,5-diazafluoren) has been synthesized and fully characterized by infrared spectrum, elemental analysis, UV-vis spectrum, etc. X-ray single-crystal diffraction analysis reveals that compound 1 shows a mononuclear structure with the europium atom in coordinating to one DAF and three TTA ligands. The mononuclear structure units are assembled into a 3-D polymer by hydrogen bonds and π-π interactions. Photoluminescent property of 1 was investigated in detail at room temperature. Complex 1 emits strong red luminescence. However, it could be quenched even by small amount of water. The fluorescence intensity at 614 nm decreases linearly with the water content increasing(vol% in acetonitrile) in the range of 0.025~0.2% under 278 nm excitation. Thermogravimetric analysis has also been studied, which demonstrates good thermal stability of 1.     

Crystal Structure,Electrochemical and Fluorescent Properties of a New Copper(Ⅱ) Coordination Polymer with 2,3-Pyridinedi-carboxylic Acid

A new copper(Ⅱ) coordination polymer [Cu_5(Hpt)_5(H_2O)_2(2,3-PCA)2]n·12 nH_2O(1) has been successfully synthesized under hydrothermal conditions with copper hydroxide, 3-(pyridin-2-yl)-1,2,4-triazole(Hpt) and 2,3-pyridinedi-carboxylic acid(2,3-PCA). The structure of the title compound was determined by X-ray diffraction analyses, elemental analyses and IR spectrum. The architecture of 1 consists of one-dimensional sandwich-like chains which are connected by extensive hydrogen bonding interactions. The solid-state photoluminescence displays an obvious emission band at 384 nm upon excitation at 340 nm. In addition, electrochemistry property has also been studied.     

Synthesis,Structure and Luminescent Properties of a Two-dimensional Cobalt(Ⅱ) Coordination Polymer Based on 2-Thiobarbituric Acid

A two-dimensional coordination polymer [Co(H_2tba)_2(DMF)_2]_n 1(H_2tba = 2-thiobarbituric acid anion, DMF = N,N-dimethylformamide) has been synthesized by Co Cl2·6H2O with the 2-thiobarbituric acid ligands under solvothermal conditions. Compound 1 was further characterized by FTIR, elemental analysis, TGA and powder XRD techniques. Single-crystal X-ray diffraction studies revealed that the title compound crystallizes in the monoclinic space group Pbca with a = 12.5948(12), b = 11.4269(11), c = 14.8939(15) ?, V = 2143.5(4) ?~3, Z = 4, Dc = 1.523 g·cm-3, F(000) = 1012, μ = 1.038 mm~(-1), R = 0.0358 and w R2 = 0.0888(I 2σ(I)). Single-crystal X-ray diffraction analysis reveals that 1 is the first two-dimensional noninterpenetrating(4, 4) net coordination polymer based on the 2-thiobarbituric acid. Coordination polymer 1 exhibits two luminescent emission spectra at 477 and 489 nm with the excitation peak at 273 nm.     

Syntheses,Crystal Structures,SHG Response and Purple Luminescent Property of Tetra(isothiocyanate) Mn(Ⅱ) and Substituted Benzyl Triphenylphosphonium Cations

Researches on multifunctional molecular materials with both nonlinear optical activity and fluorescence properties have received much interest in molecular chemistry since they have wide application prospects. Here a novel ionic compound 2(BPP)~+·[Mn(NCS)_4]~(2-)(1) was synthesized via the assembly of benzyltriphenylphosphorus chloride, isothiocyanate and manganese chloride, which displays both strong SHG response and purple luminescence. Compound 1 belongs to monoclinic system and crystallizes in Cc space group. X-ray single-crystal diffraction analysis shows that Mn~(2+) ions are tetra-coordinated with N atoms of four NCS-ions through forming a distorted tetrahedral configuration. The anion Mn(NCS)_4~(2-) forms a 1D chain structure through strong S···S interaction. At the same time, there are abundant C–H···S and π···π interactions, which further accumulate into a three-dimensional supramolecular structure. Solid-state fluorescence studies show that the complex 1 has strong purple fluorescence with emission wavelength of 396 nm under excitation wavelength 248 nm. In particular, the second harmonic generation(SHG) measurements show that compound 1 has nonlinear optical activity and its SHG response is 2.25 times that of standard potassium dihydrogen phosphate(KDP). This multifunctional molecular material with SHG response and purple fluorescence is of great significance for the development of new metal organic complexes with potential application prospects.     

Synthesis of Novel Quaternary Selenide K2CdSnSe4

<正>A novel quaternary metal selenide,K_2CdSnSe_4,was synthesized via a molten-salt reaction at 550℃.The compound has a one-dimensional structure containing a chain of _∞~1[CdSnSe_4]~(2-) anions separated by K~+ cations.The crystal belongs to the space group I-42m,with the unit cell parameters a=0.80298(11) nm,b=0.80298(11) nm, c=0.69217(14) nm,α=β=γ=90°.A reflectance spectroscopy study reveals the nature of the semiconductor with an energy gap of 1.7 eV for the compound and it has a strong optical absorption in a range of 2—5 eV.     

Ionothermal Synthesis and Characterization of a Three-dimensional Anionic Zinc-5-sulfoisophthalate Framework Charge-balanced with the 1-Ethyl-3-methylimidazolium

The ionothermal reaction of Zn(NO_3)_2·6H_2O with 5-sulfoisophthalic acid monosodium salt(NaH_2SIP) and 1,2,4-triazole in 1-ethyl-3-methylimidazolium tetrafluoroborate(EMIM-BF_4) ionic liquid has afforded the compound {(EMIM)[Zn(SIP)]}_n(1).The Zn(Ⅱ) ions are linked by the carboxylate groups of SIP~(3-) ligands to give a two-dimensional layered structure featuring the centrosymmetric dinuclear Zn_2(μ_2-COO)_2 units.The adjacent two-dimensional layers are further linked by the Zn-0 bonds between the Zn(Ⅱ) ions and the sulfonate O atoms to generate a three-dimensional anionic[Zn(SIP)]_n~(n-) framework featuring one-dimensional open channels propagating along the a axis.The imidazolium cations[EMIM]~+ derived from ionic liquid act as extraframework charge-balancing species for the anionic[Zn(SIP)]_n~(n-) framework and occupy the void space of the one-dimensional open channels.The rich ionic environments of the ionic liquid may be particularly helpful in the formation of the ionic compound 1.The roles of the ionic liquid in ionothermal synthesis and crystallization of the compound are briefly discussed.Furthermore,compound 1 displays a photoluminescent emission at 490 nm upon excitation at 406 nm.     

Synthesis, Crystal Structure and DNA Binding Studies of α,α'-Bis(3,5-bismethyl-1-pyrozolyl)- carbene-acetyl-isopropenyl Hydrazine

The title compound α,α'-bis(3,5-bismethyl-pyrozole-N-yl)-carbene-acetyl-isopro-penyl hydrazine (C16H22N6O, Mr = 314.40) has been prepared. It was characterized by elemental analysis as well as IR, MS, 1H-NMR and 13C-NMR spectra. Its crystal structure was determined by single-crystal X-ray diffraction, getting the following data: triclinic, space group P1 with a = 6.9734(16), b = 10.773(3), c = 12.001(3) A, α = 75.311(4), β = 82.695(4), γ = 77.143(4)°, Z = 2, V = 847.9(3) A3, Dc : 1.231 g/cm3, F(000) = 336 and μ(MoKα) = 0.082 mm-1 (λ = 0.71073 A). The results of crystal structure determination show that there exist intermolecular and intramolecular hydrogen bonds, resulting in a two-dimensional supramolecular framework of the title compound. The binding of the title compound to DNA was investigated by absorption, emission, and viscosity measurements. The title compound shows absorption hyperchromicity accompanied by a blue shift at about 254 nm. The binding constant Kb for the title compound has been determined to be 1.89 × 104 M-1 from absorption measurements. The addition of the title compound to DNA pretreated with EB causes appreciable reduction in the emission intensity, indicating that the DNA-bound EB fluorophore is partially replaced by the title compound. The value of K is 3.093 × 104 M-1. The relative viscosity of DNA decreased with the addition of the title compound. Results suggest that the title compound binds to DNA with a non-classical intercalative or groove interaction mode. The observed efficient nuclease activity of the title compound is interesting and may have further influences on the chemistry of DNA minor groove binders.     

Synthesis,Crystal Structure and DNA Binding Studies of α,α'-Bis(3,5-bismethyl-1-pyrozolyl)-carbene-acetyl-isopropenyl Hydrazine

The title compound α,α'-bis(3,5-bismethyl-pyrozole-N-yl)-carbene-acetyl-isopro- penyl hydrazine (C16H22N6O, Mr = 314.40) has been prepared. It was characterized by elemental analysis as well as IR, MS, 1H-NMR and 13C-NMR spectra. Its crystal structure was determined by single-crystal X-ray diffraction, getting the following data: triclinic, space group P1 with a = 6.9734(16), b = 10.773(3), c = 12.001(3) , α = 75.311(4), β = 82.695(4), γ = 77.143(4)o, Z = 2, V = 847.9(3) 3, Dc = 1.231 g/cm3, F(000) = 336 and μ(MoKα) = 0.082 mm-1 (λ = 0.71073 ). The results of crystal structure determination show that there exist intermolecular and intramolecular hydrogen bonds, resulting in a two-dimensional supramolecular framework of the title compound. The binding of the title compound to DNA was investigated by absorption, emission, and viscosity measurements. The title compound shows absorption hyperchromicity accompanied by a blue shift at about 254 nm. The binding constant Kb for the title compound has been determined to be 1.89 × 104 M-1 from absorption measurements. The addition of the title compound to DNA pretreated with EB causes appreciable reduction in the emission intensity, indicating that the DNA-bound EB fluorophore is partially replaced by the title compound. The value of K is 3.093 × 104 M-1. The relative viscosity of DNA decreased with the addition of the title compound. Results suggest that the title compound binds to DNA with a non-classical intercalative or groove interaction mode. The observed efficient nuclease activity of the title compound is interesting and may have further influences on the chemistry of DNA minor groove binders. Keywords: α,α'-bis(3,5-bismethyl-pyrozole-N-yl)-carbene-acetyl-isopropenyl, preparation, crystal structure, DNA binding     

Synthesis,Crystal Structure and Photoluminescence of a TADF Dinuclear Cu(Ⅰ) Complex

A binuclear Cu(Ⅰ) complex[Cu(PCNP)(mepypz)]_2(BF_4)_2 (1,PCNP=2,6-bis(diphenylphosphine)-benzonitrile,mepypz=2-methyl-6-(1H-pyrazol-3-yl)-pyridine was synthesized from the reaction of Cu(CH_3CN)_4BF_4,PCNP and mepypz in CH_2Cl_2 at room temperature.The compound was characterized by NMR,UV-vis and X-ray single-crystal structure analysis.It crystallizes in monoclinic space group P2_1/c with a=14.0139(5),b=11.8149(3),c=27.1248(10)?,β=96.686(4)°,V=4460.6(3)?~3,Z=2,M_r=1561.97,D_c=1.163 g/cm~3,F(000)=1600.0,μ=1.774 mm~(–1),GOOF=1.071,the final R=0.0523 and w R=0.1412 for 7919 observed reflections with I2σ(I).The Cu atoms in the complex are four-coordinated and adopt a distorted tetrahedral coordination geometry.In the solid state,the complex exhibits yellowish-green emission with a peak wavelength of 546 nm,a lifetime of 390μs,and a quantum yield of 0.45 at room temperature.The temperature-dependent investigation of luminescent properties suggests that the complex emits thermally activated delayed fluorescence (TADF) at room temperature.     

ENHANCEMENT OF THE SALT EFFECT ON THE CONFORMATION OF M. L. DNA MOLECULES BY METHYLATION

Methylated Micrococcus luteus DNA (M. L. DNA) in which the DNA methylation level was 2.39% was prepared by using Hhal DNA methylase. (The natural M. L. DNA is completely unmethylated.) The [θ]_(275) value of M. L. DNA was decreased and the —[θ]_(220-250) value was increased with increasing concentration of MgC1_2. The UV spectra of M. L. DNA at different concentration of MgCl_2 showed that a hypochromisity happens at 260nm with increasing concentration of MgC1_2. The heat-releasing of M. L. DNA also increased with increasing concentration of MgC1_2. A11 these results showed that the M. L. DNA molecules tend to shrink in space, The difference between methylated DNA and unmethylated DNA was compared. The sensitivity of methylated DNA to MgC1_2 is 40—70 fold higher than that of the unmethylated M. L. DNA.     

A Heterometallic Cu(Ⅰ)-Sr(Ⅱ) Coordination Polymer Based on Isonicotinic Acid Ligand: Synthesis,Crystal Structure,Luminescence and Photocatalytic Performance for Methylene Blue Degradation

Presented here is a new heterometallic Cu(I)-Sr(Ⅱ) coordination polymer, [Cu(3)Sr_2(isonic)_5 Br_2(H_2O)_3]n·n(H_2O)(1, Hisonic = isonicotinic acid), has been synthesized via the hydrothermal reactions of CuBr, Sr(NO_3)_2 and isonicotinic acid. The crystal structure is of triclinic system, space group P1 with a = 7.111(2), b = 14.934(4), c = 18.0255(11) ?, α = 83.137(15), β = 87.155(15), γ = 79.75(2)°, V = 1869.4(8) ?~3, C_(30)H_(29)Br_2Cu(3)N_5O_(14)Sr_2, Mr = 1209.27, Z = 2, Dc = 2.148 g/cm~3, F(000) = 1178, μ = 6.725 mm~(-1), R = 0.0500 and wR = 0.1008 for 4688 observed reflections(I 2s(I)). Single-crystal X-ray diffraction analysis revealed that compound 1 features a 3 D heterometallic framework stabilized by bifunctional isonic ligands. In addition, the luminescent and photocatalytic properties of compound 1 were also investigated at room temperature.     

Crystal Structure and DFT Studies of a Triazole Derivative： 4- （ 2-Hydrobenzylideneamino ） -3- （ 1,2,4-triazol-4-ylmethyl） 1H-1, 2,4-triazole-5 （4H） -thione

A novel triazole derivative 4-(2-hydrobenzylideneamino)-3-(1,2,4-triazol-4-ylmethyl)-1H-1,2,4-triazole-5(4H)-thione(1) was synthesized and characterized using elemental analysis, FTIR, and 1H NMR, and its crystal structure was determined via X-ray single crystal diffraction analysis. Crystal data: monoclinic, P2(1)/c, a=0.83335(9) nm, b=1.49777(16) nm, c=1.14724(12) nm, β =107.990(2)°, D=1.470 Mg/m3, and Z=4. The geometries and the vibrational frequencies were determined using the density functional theory(DFT) method at the B3LYP/ 6-31G level. To demonstrate the accuracy of the reaction route of compound 1, one of the important intermediates was also tested using the same method. The structural parameters of the two compounds calculated using the DFT study are close to those of the crystals, and the harmonic vibrations of the two compounds computed via the DFT method are in good agreement with those in the observed IR spectral data. The thermodynamic properties of the title compound were calculated, and the compound shows a good structural stability at normal temperature. The test results of biological activities show that it has a certain bactericidal ability.     

THE STUDY OF SPECTRA AND X-RAY CRYSTAL STRUCTURE OF A NOVEL BIONICS INSECTICIDE——(CH_3)_2NHCH(CH_2S_2O_3)_2Na·H_2O

IR and NMR spectra of novel bionics insecticide—C_5NS_4O_6H_(12)Na·H_2O have been studied. The molecular and crystal structures of the compound also have been determined. The compound crystallizes in the monoclinic space group C_(2h)~5, - P2_1/n with α= 8.0972. (9) , b =16.262(4), c = 10.370(3), β= 94.26(2)° and z = 4.The result shows that N atom in this compound captures a proton to form HN~ group, Na~ is in statistical disorder. Therefore, the structural formula of tho compound is (CH_3)_2HN~ —CH(CH_2S_2O_3~-)_2·1/2 (Na~ )_2·H_2O.     

CsCl-TmCl3-HCl-H2O(25 ℃)的相平衡及其固相化合物

The equilibrium solubilities of the quaternary system CsCl-TmCl₃-HCl-H₂O was determined at 25 ℃ and the corresponding equilibrium diagram was constructed. The diagram is a complicated system with limited solid solutions and formation of a new compound 3CsCl·2TmCl₃·14H₂O. The new compound has been characterized by XRD, TC-DTG and fluorescence spectrometry. Results show that upconversion spectrum exhibits at 335 nm when exciting at 860 nm, and fluorescence spectrum exhibits at 295 nm and 385 nm when exciting at 240 nm. The compound loses its crystal water by four steps at 50 to 250 ℃. Using a heat conduction calorimeter, the standard molar enthalpy of dissolution of 3CsCl·2TmCl₃·14H₂O was determined to be (-11.601 ± 0.050) kJ·mol^-1 at 298.15 K.     

SYNTHESIS AND PROPERTIES OF HOMOPOLYMER AND COPOLYMERS OBTAINED FROM 1-OCTADECENE WITH ZIRCONOCENE CATALYSTS

Studies related to the behavior of different metallocene catalysts for the homopolymerization of 1-octadecene andits copolymerization with ethylene will be presented. The metallocenes: rac-Et(Ind)_2ZrCl_2, rac-Me_2Si(Ind)_2ZrCl_2 andPh_2C(Flu)(Cp)ZrCl_2 were chosen for the homopolymerization study. They show important differences in catalytic activity athigh temperatures (≥70℃), with rac-Et(Ind)_2ZrCl_2 showing the highest activity. At lower temperatures (≤30℃) thedifferences are negligible. For the copolymerization of ethylene with 1-octadecene only the catalysts rac-Et(Ind)_2ZrCl_2 andrac-Me_2Si(Ind)_2ZrCl_2 were studied. The results show that their catalytic activity is just like that for the homopolymerizationof 1-octadecene, with higher activity for the metallocene with the Et-bridged catalyst. ~(13)C-NMR analysis shows that thecomposition of the copolymerization products depends on the catalytic systems. Copolymers obtained with rac-Me_2Si(Ind)_2ZrCl_2 have greater comonomer incorporation. Thermal analysis shows that poly-1-octadecene synthesized withthe catalyst rac-Et(Ind)_2ZrCl_2 is very dependent on the polymerization temperature. The homopolymer obtained at 70℃presents two endothermal peaks at 41℃ and 53℃, as compared with the one obtained at 30℃ which presents one wider peakwith a maximum at 67℃. For the catalyst rac-Me_2Si(Ind)_2ZrCl_2 this trend is not observed. The type of metallocene and thereaction time do not significantly change the intrinsic viscosity, but the polymerization temperature changes it drastically,giving higher values at lower temperature. Viscosity measurements on the copolymers show that an increase of comonomerconcentration in the feed reduces the molecular weight of the copolymer, and it was also found that for homopolymer, themolecular weight is independent of the catalytic systems.     

Syntheses, Structures and Fluorescent Properties of Copper（II） and Manganese（II） Helical Complexes Bridged by 4,4＇-Dipyridylsulfide

Two isostructural helical coordination polymers, {[Cu(dps)2(Hssa)-(H2O)2]·3H2O}n (1) and {[Mn(dps)2(Hssa)(H2O)2]·2H2O}n (2), have been synthesized by the solvothermal reaction of dps and H3ssa with CuCl2 or Mn(CH3COO)2 (dps = 4,4'-dipyridylsulfide, H3ssa = 5-sulfosalicylic acid). Both compounds crystallize in monoclinic, space group P21/n. In either complex, the central metal ion (CuII for compound 1 and MnII for compound 2) is surrounded by one Hssa2ˉ ligand, two coordinated aquas and three dps molecules with a N3O3 donor set in a distorted octahedral coordination geometry. Half of the dps is monodentate and another half acts as μ2-bridging ligands. It is through the bridging function of dps that the neighbouring metal centers are connected and a one-dimensional helical structure of compound 1 or 2 forms. Fluorescence studies indicate that compounds 1 and 2 have blue emission bands centered at 403 and 405 nm, respectively.     

Poly（meta-phenylene） Derivative with Rigid Twisted Biphenyl Units in Backbone： Synthesis, Structural Characterization, Photophysical Properties and Electroluminescence

A soluble poly(meta-phenylene)derivative with rigid twisted biphenyl unit was synthesized by the Yamamoto coupling reaction.The polymer is soluble in common organic solvents,and the number-average molecular weight is about 6500.The UV-Vis and quantum chemical calculation indicate that the different conformation segments named "conformers" exist in the polymer backbones;it was also further confirmed by the single crystal X-ray diffraction study of the dimeric model compound.The π-π transition of biphenyl segments of twisted and planar conformations made the polymer exhibit a strong absorption around 256 nm and a weak absorption at about 300 nm.Furthermore,the polymer exhibits a strong UV photoluminescence at 372 nm when the excitation wavelengths are longer than 300 nm.The ultraviolet-emitting electroluminescence(EL)device with the single layer structure shows EL λmax of the derivative at 370 nm.     

Synthesis and Structure of an Interlock Network Frame of Cobalt(Ⅱ) Coordination Polymer {[Co(azpy)_2(NCS)_2]·1/4EtOH·1/2H_2O}_n (azpy=4,4′-Azobispyridine)

A compound {[Co(azpy)_2(NCS)_2]·1/4EtOH·1/2H_2O}_n(1), where azpy=4,4'-azobispyridine, was synthesized and characterized by means of IR, TGA-DTA, magnetic susceptibility and X-ray single crystal diffraction. It consists of two independent sets of fully interlocked two-dimensional networks with the dihedral angle 61.7°, organized in parallel stacks of the sheets which are made of edge-shared [Co(Ⅱ)]_4 squares separated by 0. 9062nm, and defined size rhombic channels. The thermal gravimetric analysis indicates that the framework is stable up to 198℃. The variable-temperature magnetic susceptibility measurements indicated that there is a weak antiferromagnetic interaction between the cobalt(Ⅰ) ions in the complex (1).     

Synthesis, Crystal Structure, and Properties of [Cu(tren)(im)Zn(tren)](ClO_4)_3·CH_3OH as a Model Compound of BESOD

This paper reports the synthesis,properties and crystal structure of the title model compound with the ESR parameters g_∥ =2.007,g_⊥=2.191, A_∥=0.0061 cm~(-1), and A_⊥=0.0114 cm~(-1). The crystal belongs to space group C_2~2-P2_1,a=8.924(2),b=11.590(4), c=16.356(6),β =91.40(2)°,Z=2.Cu(Ⅱ) and Zn(Ⅱ) are bridged by the imidazolate ring, with the distance of 5.84.The conductivity and electronic reflectance spectrum of the complex are described.pH dependence in an aqueous solution is also investigated by potentiometric titration, and fitted by a self-written computer program. The results indicate that the imidazolate bridge splits at the side facing Zn(Ⅱ) below pH 8.