Effect of Fe_(2)O_(3)on the Structure,Physical Properties and Crystallization of CaO-Al_(2)O_(3)-SiO_(2)Glass

The calcium aluminosilicate-based glasses(CaO-Al_(2)O_(3)-SiO_(2),CAS)with different Fe_(2)O_(3)content(0.10wt%,0.50wt%,0.90wt%,and 1.30wt%)were prepared by traditional melt-quenching method.The glass network structure,thermal and mechanical properties,and crystallization behavior changes were investigated by nuclear magnetic resonance spectrometer,Fourier-transform infrared spectro-photometer,X-ray diffractometer,differential scanning calorimetry and field emission scanning electron microscope measurements.The change of Q^(n)in glass structures reveals the glass network connectivity decreases due to the increasing content of Fe_(2)O_(3)addition,resulting in the increasing of non-bridging number in glass structure.The glass densities slightly rise from 2.644 to 2.681 g/cm^(3),while Vickers’s hardness increases at first,from 6.469 to 6.901 GPa,then slightly drops to 6.745 GPa,with Fe_(2)O_(3)content increase.There is almost no thermal expansion coefficient change from different Fe_(2)O_(3)content.The glass transmittance in visible range gradually decreases with higher Fe_(2)O_(3)content,resulting from the strong absorption of Fe^(2+)and Fe^(3+)ions.The calculated activation energy from thermal analysis results first decreases from 282.70 to 231.18 kJ/mol,and then increases to 244.02 kJ/mol,with the Fe_(2)O_(3)content increasing from 0.10wt%to 1.30wt%.Meanwhile,the maximum Avrami constant of 2.33 means the CAS glasses exhibit two-dimensional crystallization.All of the CAS glass-ceramics samples contain main crystal phase of anorthite,the microstructure appears lamellar and columnar crystals.

Cryo-EM combined with image deconvolution to determine ZIF-8 crystal structure

Metal–organic frameworks(MOFs) are crystalline porous materials with tunable properties, exhibiting great potential in gas adsorption, separation and catalysis.[1,2]It is challenging to visualize MOFs with transmission electron microscopy(TEM) due to their inherent instability under electron beam irradiation. Here, we employ cryo-electron microscopy(cryoEM) to capture images of MOF ZIF-8, revealing inverted-space structural information at a resolution of up to about 1.7A and enhancing its critical electron dose to around 20 e^(-)/A^(2). In addition, it is confirmed by electron-beam irradiation experiments that the high voltage could effectively mitigate the radiolysis, and the structure of ZIF-8 is more stable along the [100] direction under electron beam irradiation. Meanwhile, since the high-resolution electron microscope images are modulated by contrast transfer function(CTF) and it is difficult to determine the positions corresponding to the atomic columns directly from the images. We employ image deconvolution to eliminate the impact of CTF and obtain the structural images of ZIF-8. As a result, the heavy atom Zn and the organic imidazole ring within the organic framework can be distinguished from structural images.

Crystal structure,phase transitions,and thermodynamic properties of magnesium metavanadate(MgV_(2)O_(6))

As a promising anode material for magnesium ion rechargeable batteries,magnesium metavanadate(MgV_(2)O_(6))has attracted considerable research interest in recent years.A MgV_(2)O_(6)sample was synthesized via a facile solid-state reaction by multistep-firing stoichiometric mixtures of MgO and V2O5 powder under an air atmosphere.The solid-state phase transition fromα-MgV_(2)O_(6)toβ-MgV_(2)O_(6)occurred at 841 K and the enthalpy change was 4.37±0.04 kJ/mol.The endothermic effect at 1014 K and the enthalpy change was 26.54±0.26 kJ/mol,which is related to the incongruent melting ofβ-MgV_(2)O_(6).In situ XRD was performed to investigate phase transition of the as-prepared MgV_(2)O_(6)at high temperatures.The cell parameters obtained by Rietveld refinement indicated that it crystallizes in a monoclinic system with the C2/m space group,and the lattice parameters of a=9.280 A°,b=3.501 A°,c=6.731 A°,β=111.76°.The solid-state phase transition fromα-MgV_(2)O_(6)toβ-MgV_(2)O_(6)was further studied by thermal kinetics,indicating that this process is controlled first by a fibril-like mechanism and then by a spherulitic-type mechanism with an increasing heating rate.Additionally,the enthalpy change of MgV_(2)O_(6)at high temperatures was measured utilizing the drop calorimetry,heat capacity was calculated and given as:Cp=208.3+0.03583T-4809000T^(−2)(298-923 K)(J mol^(−1)K^(−1)),the high-temperature heat capacity can be used to calculate Gibbs free energy of MgV_(2)O_(6)at high temperatures.

The Crystal Structure Study of CaSrFe0.75Co0.75Mn0.5O6−δ by Neutron Diffraction

The crystal structure of CaSrFe0.75Co0.75Mn0.5O6−δ is investigated through neutron diffraction techniques in this study. The material is synthesized using a solid-state synthesis method at a temperature of 1200˚C. Neutron diffraction data is subjected to Rietveld refinement, and a comparative analysis with X-ray diffraction (XRD) data is performed to unravel the structural details of the material. The findings reveal that the synthesized material exhibits a cubic crystal structure with a Pm-3m phase. The neutron diffraction results offer valuable insights into the arrangement of atoms within the lattice, contributing to a comprehensive understanding of the material’s structural properties. This research enhances our knowledge of CaSrFe0.75Co0.75Mn0.5O6−δ, with potential implications for its applications in various technological and scientific domains.

Analyses of Reaction Mechanisms among Different Sulfonation Reagents and m-Diphenylamine and Crystal Structures of the Formed Compounds

In the traditional process, m-phenylenediamine reacts with fuming sulfuric acid at high temperature to get intermediates, and then after dehydration occurs intramolecular rearrangement to get 2,4-diaminobenzenesulfonic acid. Traditional methods need to consume a lot of fuming sulfuric acid or concentrated sulfuric acid, resulting in high industrial large-scale production cost, more waste, and posing a serious environmental pollution risk. In this thesis, three different sulfonation reagents were used for the sulfonation reaction of m-phenylenediamine, and the reaction mechanisms and crystal structures of the three pathways were investigated. The three routes are: 1) one-step synthesis of monosulfonated compound 1 from raw material and sulfur trioxide (SO3);2) rapid reaction of raw material and chlorosulfonic acid to synthesize bisulfonated compound 2;3) direct eutectic crystallization of raw material and ordinary sulfuric acid to obtain compound 3. The crystal structure of the compounds synthesized by three paths was analyzed by X-ray single crystal diffraction, and compound 1 was characterized by NMR, Fourier infrared spectra, UV-visible spectrum and Mass spectrometry. The one-step synthesis of SO3 as a sulfonation reagent has the advantages of mild reaction conditions, simple operation and low cost.

Hydrothermal Synthesis,Crystal Structure and Fluorescence Spectrum Studies of a Supramolecular Compound {[2-(2-Pyridyl)benzimidazoleH_2]^(2+)·[SbCl_5]^(2-)}_2

A new supramolecular compound, { [2-（2-pyridyl）benzimidazoleH2]2＋.[SBC15]2-}2, was synthesized by the hydrothermal reaction of o-diaminobenzene, 2-pyridinecarboxylie acid and SbCl3 in 1：1 HC1 solution, and characterized by chemical analysis, elemental analysis, IR spectra, thermogravimetfic analysis and fluorescence spectra. The crystal structure was deter- mined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P211c, with a = 16.0397（13）, b = 14.3189（12）, c = 15.6370（13） A, β = 105.8980（10）°, V = 3454.0（5） A3, Z = 4, C24H22Cl10N6Sb2, Mr = 992.48, Dc = 1.909 g/cm3,/z = 2.366 mm-1, S = 1.010, F（000） = 1920, R = 0.0254 and wR = 0.0555. The coordination anion, [SbCl5]2- which is a distorted tetragonal pyramid, is composed by coordinating action with Sb3＋ ion and five adjacent chloride ions. Every four coordination anions of [SbCl5]2- form a biquaternion ring structure through the secondary bonding of Sb...Cl. Moreover, the compound adopts a three-dimensional network supramolecular structure because of the hydrogen bonds and π-π stacking between the rings and the 2-（2-pyridyl）benzimidazole divalent cations. The title compound also shows good fluorescent behaviors.

Syntheses,Crystal Structures and Fluorescence Properties of Two Complexes Based on a New Chiral Ligand

A new homochiral ligand,（R）-2-（4-pyridyl）-4,5-dihydrothiazole-4-carboxylic acid（HL^R）, has been synthesized. Two complexes, [ZnL2^R（H2O）2]·H2O（1） and [MnL2^R（H2O）2]？H2O（2） have been prepared by the reactions of Zn（Ⅱ） and Mn（Ⅱ） ions with the ligand HLR, and characterized by single-crystal X-ray diffraction analysis and fluorescence. Complexes 1 and 2 are isomorphs, and both of the Zn（Ⅱ） and Mn（Ⅱ） centers in 1 and 2 are six-coordinated by the two NO units of two ligands and two water oxygen atoms, showing distorted octahedral coordination geometry. Complexes 1 and 2 show fluorescent properties in the solid state at room temperature.

Synthesis,crystal structure and fluorescence of a new europium complex with 2-bromobenzoate and 2,2'-bipyridine

A new complex of {[Eu2(2-BrBA)6(2,2’-bpy)2]2·CH3CH2OH·H2O} (2-BrBA=2-bromobenzoate; 2,2’-bpy=2,2’-bipyridine) was prepared by solvent method and characterized with X-ray single-crystal diffraction, IR spectroscopy, UV spectroscopy, and fluorescence spectroscopy. The complex crystallized in triclinic crystal system, Pī space group, with a=1.17196(4) nm, b=2.36142(9) nm, c=2.59151(9) nm, α=113.266(2)°, β=101.100(2)°, and γ=94.400(2)°. Two independent dinuclear molecules were contained in the asymmetric unit. The two molecules were similar to each other. Each Eu(Ⅲ) ion was nine-coordinated with seven oxygen atoms from five 2-BrBA ligands and two nitrogen atoms from 2,2’-bpy molecule. The carboxylate groups acted as bidentate-chelating, bidentate-bridging and chelating-bridging coordination modes. The complex adopted a distorted monocapped square-antiprism coordination geometry. Five peaks at 579, 591, 613, 652, and 697 nm appeared in the fluorescence spectrum, corresponding to 5D0→7F0, 5D0→7F1, 5D0→7F2, 5D0→7F3, and 5D0→7F4 transition emissions of the Eu(Ⅲ) ion, respectively.

A Zinc(Ⅱ) Coordination Framework Based on Terpyridine and 5-Nitroisophthalic Acid Mixed Ligands: Synthesis, Crystal Structure and Fluorescence Property

A new coordination framework, {[Zn（L1）（5-nipc）]·H2O}n（1, L1 = 4ˊ-（4-pyridyl）-4,2ˊ：6ˊ,4ˊˊ-terpyridine, 5-nipc = 5-nitroisophthalic acid）, has been prepared under hydrothermal conditions, and determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR and powder X-ray diffraction. Complex 1 crystallizes in monoclinic, space group C2/c with a = 29.983（9）, b = 13.709（3）, c = 14.391（3）A, β = 114.93（4）°, V = 5364（2） A3, Dc = 1.493 g/cm^3, C28H19N5O7 Zn, Mr = 602.85, F（000） = 2464, μ（Mo Kα） = 0.972 mm^-1, Z = 8, R = 0.0935 and w R = 0.1509 for 4724 observed reflections（I 〉 2σ（I））. The structure of 1 exhibits a three-dimensional（3D） network with a layer-pillar structure. The fluorescence property of 1 is also investigated.

Alkynyl-modified Naphthalimide:Synthesis,Crystal Structure and Fluorescence Spectrum

A novel alkynyl substituted N-aryl-1,8-naphthalimide II （C20H11NO2） was synthesized for the discovery and evaluation of new fluorescence probes, and was characterized by X-ray crystal diffraction. It crystallizes in monoclinic, space group P21/n with a = 15.898（3）, b = 5.0102（10）, c = 17.962（4）A, β = 92.97（3）°, V = 1428.7（5） A^3, Z = 4, Mr = 297.30, Dc = 1.382 g/cm^3, F（000） = 616,/J = 0.090 mm^-1, S = 1.011, the final R = 0.0542 and wR = 0.1204 for 1669 observed reflections with I 〉 2σ（I） and 212 variable parameters. Hydrogen-bounding and n-stacking interactions were discussed. The influence of acetylene group on the fluorescence properties was also investigated. In comparison with N-phenyl-1,8-naphthalimide I （C18H11NO2）, few new structure characters and fluorescence properties of the title compound have been found.

Crystal Structure, One-and Two-photon Excited Fluorescence and Bioimaging of a D-π-A Structural Triphenylamine Derivative

An electron donor-π-bridge-electron acceptor(D-π-A) optical functional organic compound comprising a triphenylamine moiety as the electron donor and pyridine moiety as the electron acceptor was synthesized. The structure of the compound was solved by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21, with a = 9.753(5), b = 8.815(5), c = 25.554(5) ?, β = 96.315(5)°, V = 2184(2) ?~3, Z = 2, D_c = 1.136 g/m^3, F(000) = 792, Μr = 746.92, μ = 0.069 mm^(-1), the final R = 0.0658 and wR = 0.1730 for 6790 observed reflections with I > 2(I). Study of nonlinear optical properties shows that the compound exhibits excellent two-photon excited fluorescence with the two-photon absorption cross-section value of 116 GM. The structure-property relationship was researched in detail through X-ray crystallography and quantum chemical calculation. Result of living cell imaging experiment shows its potential in fluorescence microscopy bioimaging.

Synthesis, crystal structure, and fluorescence of two dimeric europium(III) complexes with 2-(trifluoromethyl)benzoate

Two complexes [Eu2（2-TFMBA）6（2,2′-bipy）2]·2H2O （1） and Eu2（2-TFMBA）6（1,10-phen）2 （2） （2-TFMBA=2-（Trifluoromethyl） benzoate; 2,2′-bipy=2,2′-bipyridine; 1,10-phen= 1,10-phenanthroline） were synthesized by solvent method and determined by X-ray diffraction analysis. Complex 1 crystallizes in monoclinic system with space group P21/c, whereas complex 2 crystallizes in triclinic system with space group Pi. Both are binuclear molecules with an inversion center. In complex 1, two center Eu^3＋ ions are linked together by four 2-TFMBA ligands in bidentate-bridging mode. Each Eu^3＋ ion is eight-coordinated with six O atoms from five 2-TFMBA ligands and two N atoms from one 2,2′-bipy molecule. In complex 2, two center Eu^3＋ ions are linked together by four 2-TFMBA ligands in two modes, namely, bidentate-bridging and tridentate-bridging. Each Eu^3＋ ion is nine-coordinated with seven O atoms from five 2-TFMBA ligands and two N atoms from one 1,10-phen molecule. The two complexes both exhibited strong red fluorescence under ultraviolet light, and the ^5D0→^7Fj （j=0-4） transition emissions of Eu^3＋ ion were observed in their emission spectra.

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.

Synthesis,Crystal Structure,Fluorescence Properties and Geometrical Calculation of 4,8,10-Trimethyl-2-(3,5-dimethylpyrazol)-pyrido-[2',3':3,4]-pyrazol[1,5-a]-pyrimidin

A novel compound 4,8,10-trimethyl-2-（3,5-dimethylpyrazol）-pyrido-[2＇,3＇：3,4]-py-razol-[1,5-5-a]-pyrimidine（C17H18N6） has been synthesized from 2,6-dichloro-4-methylnico-tino-nitrile,hydrazine and acetylacetone by substitution and cyclolization.The structure was charac-terized by elemental analysis,1H NMR and IR,and single-crystal structure was determined by X-ray diffraction analysis.The compound crystallizes in the monoclinic system,space group P21/c with a = 8.0338（9）,b = 28.618（3）,c = 7.2688（8）,β = 111.051（2）o,V = 1559.6（3） 3,Z = 4,Dc = 1.305 g/cm3,μ = 0.083 mm-1,Mr = 306.37,F（000） = 648,S = 0.971,the final R = 0.0795 and wR = 0.1746 for 1457 observed reflections（Ⅰ 〉 2σ（Ⅰ））.The results demonstrate that the pyridine,pyrazole and pyrimidine rings are nearly coplanar,which is evident from the dihedral angles among the four rings in the range of 0.13～4.15o.The face-to-face π-π stacking interactions among pyridine,pyrazol and pyrimidine rings result in a supramolecular crystal,in which they seem to be effective in stabilizing the structure.Meanwhile,the fluorescence properties of the title compound were discussed,which showed very strong fluorescence.The calculated results（selected bond lengths,bond angles and torsion angles） are all typical and agree well with the experimental results,which demonstrates that B3LYP/6-31＋G＊ is suitable for the title compound.

Hydrothermal Synthesis, Crystal Structure and Fluorescence Properties of a Three-dimensional Triply-bridged Binuclear Zinc(Ⅱ) Complex [Zn_2(Mba)_3(Phen)_2EtOH)]·ClO_4

The novel complex [Zn2（Mba）3（Phen）2EtOH）]·ClO4 （Hrnba = methoxybenzoic acid, Phen = 1,10-phenanthroline, EtOH = ethanol） was synthesized by hydrothermal reactions, and its structure was determined by X-ray diffraction. The crystal belongs to the triclinic system, space group Pi with a = 1.15362（1）, b = 1.3655（3）, c = 1.61451（1） nm, α= 72.842（2）, β = 83.259（3）, y = 72.083（2）°, V = 2.3112（6） nm3, Z = 2,μ（MoKa） = 11.71 cm-1, F（000） = 1120, R = 0.0552 and wR = 0.1157 （I 〉 2σ（I））. The two centric zinc（H） ions in the complex locate in a distorted octahedral coordination geometry and a distorted trigonal bipyramid coordination geometry, respectively. Two bridging bidentate carboxyl groups and a μ2-O carboxyl group from three methoxybenzoic acids act as the bridge to link two Zn（Ⅱ） ions. The asymmetric units are connected by π-π packing interactions between aromatic rings to form a three-dimensional supramolecular network. The experimental results show a good fluorescence property for the complex.

Synthesis,Crystal Structure and Fluorescence Property of a New Trinuclear Nickel(Ⅱ) Complex Bridged by 2,6-Pyridine Dicarboxylic Acid

A new trinuclear nickel complex,[Ni3（pdc）3（2,2＇-bipy）3（H2O）2]·2H2O（H2pdc = pyridine 2,6-dicarboxylic acid,2,2＇-bipy = 2,2＇-bipyridine） has been hydrothermally synthesized and characterized by IR,elemental analysis and X-ray diffraction methods.Crystal data for this complex：monoclinic,space group P21/n,a = 21.206（4）,b = 10.002（2）,c = 28.066（6）,β = 108.18（3）°,C51H41N9Ni3O16,Mr = 1212.06,V = 5.656（2） nm3,Dc = 1.423 g·cm-3,μ（MoKα） = 1.062 mm-1,Z = 4,F（000） = 2488,GOOF = 1.034,the final R = 0.0543 and wR = 0.1237 for 6149 observed reflections with Ⅰ 〉 2σ（Ⅰ）.In the complex,three nickel（Ⅱ） ions are bridged by the pyridine 2,6-dicarboxylic acid groups,and all nickel（Ⅱ） ions are seven-coordinated by nitrogen atoms of 2,2＇-bipyridine and pyridine 2,6-dicarboxylic acid and oxygen atoms from pyridine 2,6-dicarboxylic and water to adopt a severely distorted pentagonal bipyramidal geometry.The emission and excitation peaks of the complex in ethanol solutions are located at 336 and 316 nm,respectively.

One Novel 2D Co(Ⅱ) Polymer with 1,2,3-Triazole Derivative: Crystal Structure, Fluorescence and Hirshfeld Surface Analysis

One new polymer [Co（L）（H2O）2]n（1） was synthesized by 4-（ethoxycarbonyl）-5-methyl-1H-1,2,3-triazole-1-carboxylic acid（Emtc） under the in situ solvent thermal reaction（H2L = 1-（carboxymethyl）-5-methyl-1H-1,2,3-triazole-4-carboxylic acid）. The title complex performs a wave-like 2D framework and the ligand H2L demonstrates the coordination mode as μ4-η-2：η-1η-1：η-1. The crystal structure has been established by single-crystal X-ray diffraction, and characterized by FT-IR. Fluorescent property was investigated in this work. Hirshfeld surface analysis has also been carried out on 1, and obvious main intermolecular interactions are observed.

Conjugate Fluorescent Compound Based on Pyrene-imidazole: Design, Synthesis, Crystal Structure and Fluorescence Property

Pyrenes are an important group of polycyclic aromatic hydrocarbons(PAHs). In order to expand the diversity of conjugate compounds based on pyrene, two new isomeric compounds anti-PyDTPAI and syn-PyDTPAI containing pyrene, imidazole and triphenylamine are synthesized via a one-pot cyclization reaction and characterized. The anti-PyDTPAI is characterized by single-crystal X-ray diffraction which crystallizes in monoclinic, space group P2_1/n with a = 10.132(4), b = 14.997(7), c = 18.968(9) ?, β = 95.543(19)o, V = 2869(2) ?~3, Z = 2, F(000) = 1092, Dc = 1.196 Mg/m^3, Mr = 1033.28 and μ(Mo Kα) = 0.070 mm^(-1). The presence of intermolecular C–H···π interactions results in the stability of the compound. The crystal structure shows a centrosymmetric, coplanar configuration towards pyrene-imidazole segment and a slip-stacked packing mode across the longer molecular axis which is similar to the J-type aggregation. The investigation of UV-vis absorption and fluorescence in solution indicates a strong blue emission under the ultraviolet light excitation. The two isomers also display high thermal stability which is proved by differential scanning calorimetry(DSC) and thermogravimetric analysis(TGA). Additionally, the molecular structure and HOMO and LUMO levels are calculated by density functional theory(DFT) at the B3 LYP/6-31 G(d) level.

One Novel Mn(Ⅱ)Complex with 1-Substituted-1H-1,2,3-triazole-4-carboxylic Acid:Crystal Structure,Fluorescence and Hirshfeld Surface Analysis

The crystal structure of one novel Mn（II） complex, [Mn（pmta）_3]_2[Mn（H_2O）_6]·4H_2O（1）, is reported（Hpmta = 5-methyl-1-phenyl-1H-1,2,3-triazole-4-carboxylic acid）. In the title compound, the asymmetric unit consists of a [Mn（pmta_）3]ˉ anion, half [Mn（H_2O）_6]^（2＋） counter cation and two lattice H_2O molecules, and the intra- and intermolecular hydrogen bonds connect the complex into a supramolecular structure. The liquid-state fluorescence spectra of complex 1 have been determined. Hirshfeld surface analysis was also studied. The main intermolecular interactions in the complex are O···H and H···H contacts.

Crystal Structures,Characterizations and Fluorescence Properties of Two 3D Ca(Ⅱ)/Sr(Ⅱ)Coordination Polymers Based on 2-Sulfoterephthalate

Two alkaline earth metal coordination polymers [M（2-Hstp）（H2O）] （M = Ca2＋ （1） and Sr2＋ （2）, 2-H3stp = 2-sulfoterephthalate） were synthesized under hydrothermal conditions by the precursor [Mn（2-Hstp）2（4,4？-Hbpy）2] and alkaline earth metal salts. The two alkaline earth complexes are not isomorphic. Complex 1 crystallizes in the monoclinic space group P21/m, while 2 in the monoclinic space group P21/c, despite of their similar formulas. In 1, the Ca2＋ ion lies in a seven-coordinated pentagon bipyramidal configuration, coordinated with five 2-Hstp2- anions and one water molecule. However, the Sr2＋ ion in 2 is coordinated by nine oxygen atoms to form a single-capped square antiprism polyhedron. Both 1 and 2 exhibit π-π＊ emission of the 2-sulfotere- phthalate ligand.